Biology

Biology 0610 — specification explorer

All 388 specification statements from the official Cambridge International specification, as printed.

Paper/unit applicability has not been derived for this course yet — the statements below are the parsed specification, as printed.

1. Characteristics and classification of living organisms

1. Characteristics of living organisms

1.1.1
Describe the characteristics of living organisms by describing: part of an organism causing a change of position or place that break down nutrient molecules and release energy for metabolism respond to changes in the internal or external environment dry mass more of the same kind of organism products of metabolism and substances in excess of requirements energy, growth and development:
- (a) movement as an action by an organism or
- (b) respiration as the chemical reactions in cells
- (c) sensitivity as the ability to detect and
- (d) growth as a permanent increase in size and
- (e) reproduction as the processes that make
- (f) excretion as the removal of the waste
- (g) nutrition as the taking in of materials for

2. Concept and uses of classification systems

1.2.1State that organisms can be classified into groups by the features that they share
1.2.2Describe a species as a group of organisms that can reproduce to produce fertile offspring
1.2.3Describe the binomial system of naming species as an internationally agreed system in which the scientiﬁc name of an organism is made up of two parts showing the genus and species
1.2.4Construct and use dichotomous keys based on identifiable features
1.2.5Explain that classiﬁcation systems aim to reﬂect evolutionary relationships
1.2.6Explain that the sequences of bases in DNA are used as a means of classiﬁcation
1.2.7Explain that groups of organisms which share a more recent ancestor (are more closely related) have base sequences in DNA that are more similar than those that share only a distant ancestor

3. Features of organisms

1.3.1State the main features used to place animals and plants into the appropriate kingdoms
1.3.2
State the main features used to place organisms into groups within the animal kingdom, limited to: birds, reptiles, amphibians, fish insects, arachnids, crustaceans:
- (a) the main groups of vertebrates: mammals,
- (b) the main groups of arthropods: myriapods,
1.3.3Classify organisms using the features identified in 1.3.1 and 1.3.2
1.3.4State the main features used to place all organisms into one of the five kingdoms: animal, plant, fungus, prokaryote, protoctist
1.3.5State the main features used to place organisms into groups within the plant kingdom, limited to ferns and flowering plants (dicotyledons and monocotyledons)
1.3.6Classify organisms using the features identified in 1.3.4 and 1.3.5
1.3.7State the features of viruses, limited to a protein coat and genetic material

2. Organisation of the organism

1. Cell structure

2.1.1Describe and compare the structure of a plant cell with an animal cell, limited to: cell wall, cell membrane, nucleus, cytoplasm, chloroplasts, ribosomes, mitochondria, vacuoles
2.1.2Describe the structure of a bacterial cell, limited to: cell wall, cell membrane, cytoplasm, ribosomes, circular DNA, plasmids
2.1.3Identify the cell structures listed in 2.1.1 and 2.1.2 in diagrams and images of plant, animal and bacterial cells
2.1.4Describe the functions of the structures listed in 2.1.1 and 2.1.2 in plant, animal and bacterial cells
2.1.5State that new cells are produced by division of existing cells
2.1.6
State that specialised cells have specific functions, limited to: trachea and bronchi:
- (a) ciliated cells – movement of mucus in the
- (b) root hair cells – absorption
- (c) palisade mesophyll cells – photosynthesis
- (d) neurones – conduction of electrical impulses
- (e) red blood cells – transport of oxygen
- (f) sperm and egg cells (gametes) – reproduction
2.1.7Describe the meaning of the terms: cell, tissue, organ, organ system and organism as illustrated by examples given in the syllabus

2. Size of specimens

2.2.1State and use the formula: magnification = image size ÷ actual size
2.2.2Calculate magnification and size of biological specimens using millimetres as units
2.2.3Convert measurements between millimetres (mm) and micrometres ( μ m)

3. Movement into and out of cells

1. Diffusion

3.1.1Describe diffusion as the net movement of particles from a region of their higher concentration to a region of their lower concentration (i.e. down a concentration gradient), as a result of their random movement
3.1.2State that the energy for diffusion comes from the kinetic energy of random movement of molecules and ions
3.1.3State that some substances move into and out of cells by diffusion through the cell membrane
3.1.4Describe the importance of diffusion of gases and solutes in living organisms
3.1.5Investigate the factors that influence diffusion, limited to: surface area, temperature, concentration gradient and distance

2. Osmosis

3.2.1Describe the role of water as a solvent in organisms with reference to digestion, excretion and transport
3.2.2State that water diffuses through partially permeable membranes by osmosis
3.2.3State that water moves into and out of cells by osmosis through the cell membrane
3.2.4Investigate osmosis using materials such as dialysis tubing
3.2.5Investigate and describe the effects on plant tissues of immersing them in solutions of different concentrations
3.2.6State that plants are supported by the pressure of water inside the cells pressing outwards on the cell wall
3.2.7Describe osmosis as the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane
3.2.8Explain the effects on plant cells of immersing them in solutions of different concentrations by using the terms: turgid, turgor pressure, plasmolysis, flaccid
3.2.9Explain the importance of water potential and osmosis in the uptake and loss of water by organisms

3. Active transport

3.3.1Describe active transport as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e. against a concentration gradient), using energy from respiration
3.3.2Explain the importance of active transport as a process for movement of molecules or ions across membranes, including ion uptake by root hairs
3.3.3State that protein carriers move molecules or ions across a membrane during active transport

4. Biological molecules

1. Biological molecules

4.1.1List the chemical elements that make up: carbohydrates, fats and proteins
4.1.2
State that large molecules are made from smaller molecules, limited to:
- (a) starch, glycogen and cellulose from glucose
- (b) proteins from amino acids
- (c) fats and oils from fatty acids and glycerol
4.1.3
Describe the use of:
- (a) iodine solution test for starch
- (b) Benedict’s solution test for reducing sugars
- (c) biuret test for proteins
- (d) ethanol emulsion test for fats and oils
- (e) DCPIP test for vitamin C
4.1.4
Describe the structure of a DNA molecule: helix strands together A with T, and C with G (full names are not required):
- (a) two strands coiled together to form a double
- (b) each strand contains chemicals called bases
- (c) bonds between pairs of bases hold the
- (d) the bases always pair up in the same way:

5. Enzymes

1. Enzymes

5.1.1Describe a catalyst as a substance that increases the rate of a chemical reaction and is not changed by the reaction
5.1.2Describe enzymes as proteins that are involved in all metabolic reactions, where they function as biological catalysts
5.1.3Describe why enzymes are important in all living organisms in terms of a reaction rate necessary to sustain life
5.1.4Describe enzyme action with reference to the shape of the active site of an enzyme being complementary to its substrate and the formation of products
5.1.5Investigate and describe the effect of changes in temperature and pH on enzyme activity with reference to optimum temperature and denaturation
5.1.6Explain enzyme action with reference to: active site, enzyme-substrate complex, substrate and product
5.1.7Explain the specificity of enzymes in terms of the complementary shape and fit of the active site with the substrate
5.1.8Explain the effect of changes in temperature on enzyme activity in terms of kinetic energy, shape and fit, frequency of effective collisions and denaturation
5.1.9Explain the effect of changes in pH on enzyme activity in terms of shape and fit and denaturation

6. Plant nutrition

1. Photosynthesis

6.1.1Describe photosynthesis as the process by which plants synthesise carbohydrates from raw materials using energy from light
6.1.2State the word equation for photosynthesis as: carbon dioxide + water → glucose + oxygen in the presence of light and chlorophyll
6.1.3State that chlorophyll is a green pigment that is found in chloroplasts
6.1.4State that chlorophyll transfers energy from light into energy in chemicals, for the synthesis of carbohydrates
6.1.5
Outline the subsequent use and storage of the carbohydrates made in photosynthesis, limited to:
- (a) starch as an energy store
- (b) cellulose to build cell walls
- (c) glucose used in respiration to provide energy
- (d) sucrose for transport in the phloem
- (e) nectar to attract insects for pollination
6.1.6
Explain the importance of:
- (a) nitrate ions for making amino acids
- (b) magnesium ions for making chlorophyll
6.1.7Investigate the need for chlorophyll, light and carbon dioxide for photosynthesis, using appropriate controls
6.1.8Investigate and describe the effects of varying light intensity, carbon dioxide concentration and temperature on the rate of photosynthesis
6.1.9Investigate and describe the effect of light and dark conditions on gas exchange in an aquatic plant using hydrogencarbonate indicator solution
6.1.10State the balanced chemical equation for photosynthesis as: 6CO + 6H O → C H O + 6O continued
6.1.11Identify and explain the limiting factors of photosynthesis in different environmental conditions

2. Leaf structure

6.2.1State that most leaves have a large surface area and are thin, and explain how these features are adaptations for photosynthesis
6.2.2Identify in diagrams and images the following structures in the leaf of a dicotyledonous plant: chloroplasts, cuticle, guard cells and stomata, upper and lower epidermis, palisade mesophyll, spongy mesophyll, air spaces, vascular bundles, xylem and phloem
6.2.3Explain how the structures listed in 6.2.2 adapt leaves for photosynthesis

7. Human nutrition

1. Diet

7.1.1Describe what is meant by a balanced diet
7.1.2
State the principal dietary sources and describe the importance of:
- (a) carbohydrates
- (b) fats and oils
- (c) proteins
- (d) vitamins, limited to C and D
- (e) mineral ions, limited to calcium and iron
- (f) fibre (roughage)
- (g) water
7.1.3State the causes of scurvy and rickets

2. Digestive system

7.2.1
Identify in diagrams and images the main organs of the digestive system, limited to: stomach, small intestine (duodenum and ileum) and large intestine (colon, rectum, anus) liver and gall bladder:
- (a) alimentary canal: mouth, oesophagus,
- (b) associated organs: salivary glands, pancreas,
7.2.2
Describe the functions of the organs of the digestive system listed in 7.2.1, in relation to: and drink, into the body the intestines into the blood cells from the body as faeces:
- (a) ingestion – the taking of substances, e.g. food
- (b) digestion – the breakdown of food
- (c) absorption – the movement of nutrients from
- (d) assimilation – uptake and use of nutrients by
- (e) egestion – the removal of undigested food

3. Physical digestion

7.3.1Describe physical digestion as the breakdown of food into smaller pieces without chemical change to the food molecules
7.3.2State that physical digestion increases the surface area of food for the action of enzymes in chemical digestion
7.3.3Identify in diagrams and images the types of human teeth: incisors, canines, premolars and molars
7.3.4Describe the structure of human teeth, limited to: enamel, dentine, pulp, nerves, blood vessels and cement, and understand that teeth are embedded in bone and the gums
7.3.5Describe the functions of the types of human teeth in physical digestion of food
7.3.6Describe the function of the stomach in physical digestion
7.3.7Outline the role of bile in emulsifying fats and oils to increase the surface area for chemical digestion

4. Chemical digestion

7.4.1Describe chemical digestion as the break down of large insoluble molecules into small soluble molecules
7.4.2State the role of chemical digestion in producing small soluble molecules that can be absorbed
7.4.3
Describe the functions of enzymes as follows: reducing sugars and glycerol:
- (a) amylase breaks down starch to simple
- (b) proteases break down protein to amino acids
- (c) lipase breaks down fats and oils to fatty acids
7.4.4State where, in the digestive system, amylase, protease and lipase are secreted and where they act
7.4.5Describe the functions of hydrochloric acid in gastric juice, limited to killing harmful microorganisms in food and providing an acidic pH for optimum enzyme activity
7.4.6
Describe the digestion of starch in the digestive system: the membranes of the epithelium lining the small intestine:
- (a) amylase breaks down starch to maltose
- (b) maltase breaks down maltose to glucose on
7.4.7
Describe the digestion of protein by proteases in the digestive system: conditions of the stomach conditions of the small intestine:
- (a) pepsin breaks down protein in the acidic
- (b) trypsin breaks down protein in the alkaline
7.4.8Explain that bile is an alkaline mixture that neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action

5. Absorption

7.5.1State that the small intestine is the region where nutrients are absorbed
7.5.2State that most water is absorbed from the small intestine but that some is also absorbed from the colon
7.5.3Explain the significance of villi and microvilli in increasing the internal surface area of the small intestine
7.5.4Describe the structure of a villus
7.5.5Describe the roles of capillaries and lacteals in villi

8. Transport in plants

1. Xylem and phloem

8.1.1
State the functions of xylem and phloem: and support acids:
- (a) xylem – transport of water and mineral ions,
- (b) phloem – transport of sucrose and amino
8.1.2Identify in diagrams and images the position of xylem and phloem as seen in sections of roots, stems and leaves of non-woody dicotyledonous plants
8.1.3
Relate the structure of xylem vessels to their function, limited to: are not required) form a long continuous tube:
- (a) thick walls with lignin (details of lignification
- (b) no cell contents
- (c) cells joined end to end with no cross walls to

2. Water uptake

8.2.1Identify in diagrams and images root hair cells and state their functions
8.2.2State that the large surface area of root hairs increases the uptake of water and mineral ions
8.2.3Outline the pathway taken by water through the root, stem and leaf as: root hair cells, root cortex cells, xylem, mesophyll cells
8.2.4Investigate, using a suitable stain, the pathway of water through the above-ground parts of a plant

3. Transpiration

8.3.1Describe transpiration as the loss of water vapour from leaves
8.3.2State that water evaporates from the surfaces of the mesophyll cells into the air spaces and then diffuses out of the leaves through the stomata as water vapour
8.3.3Investigate and describe the effects of variation of temperature and wind speed on transpiration rate
8.3.4Explain how water vapour loss is related to: the large internal surface area provided by the interconnecting air spaces between mesophyll cells and the size and number of stomata
8.3.5Explain the mechanism by which water moves upwards in the xylem in terms of a transpiration pull that draws up a column of water molecules, held together by forces of attraction between water molecules
8.3.6Explain the effects on the rate of transpiration of varying the following factors: temperature, wind speed and humidity
8.3.7Explain how and why wilting occurs

4. Translocation

8.4.1Describe translocation as the movement of sucrose and amino acids in phloem from sources to sinks
8.4.2
Describe: sucrose or amino acids sucrose or amino acids:
- (a) sources as the parts of plants that release
- (b) sinks as the parts of plants that use or store
8.4.3Explain why some parts of a plant may act as a source and a sink at different times

9. Transport in animals

1. Circulatory systems

9.1.1Describe the circulatory system as a system of blood vessels with a pump and valves to ensure one-way flow of blood
9.1.2Describe the single circulation of a fish
9.1.3Describe the double circulation of a mammal
9.1.4Explain the advantages of a double circulation

2. Heart

9.2.1Identify in diagrams and images the structures of the mammalian heart, limited to: muscular wall, septum, left and right ventricles, left and right atria, one-way valves and coronary arteries
9.2.2State that blood is pumped away from the heart in arteries and returns to the heart in veins
9.2.3State that the activity of the heart may be monitored by: ECG, pulse rate and listening to sounds of valves closing
9.2.4Investigate and describe the effect of physical activity on the heart rate
9.2.5Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible risk factors including: diet, lack of exercise, stress, smoking, genetic predisposition, age and sex
9.2.6Discuss the roles of diet and exercise in reducing the risk of coronary heart disease
9.2.7Identify in diagrams and images the atrioventricular and semilunar valves in the mammalian heart
9.2.8
Explain the relative thickness of: ventricles those of the ventricles:
- (a) the muscle walls of the left and right
- (b) the muscle walls of the atria compared to
9.2.9Explain the importance of the septum in separating oxygenated and deoxygenated blood
9.2.10Describe the functioning of the heart in terms of the contraction of muscles of the atria and ventricles and the action of the valves
9.2.11Explain the effect of physical activity on the heart rate

3. Blood vessels

9.3.1Describe the structure of arteries, veins and capillaries, limited to: relative thickness of wall, diameter of the lumen and the presence of valves in veins
9.3.2State the functions of capillaries
9.3.3
Identify in diagrams and images the main blood vessels to and from the: artery and pulmonary vein pulmonary vein:
- (a) heart, limited to: vena cava, aorta, pulmonary
- (b) lungs, limited to: pulmonary artery and
- (c) kidney, limited to: renal artery and renal vein
9.3.4Explain how the structure of arteries and veins is related to the pressure of the blood that they transport
9.3.5Explain how the structure of capillaries is related to their functions
9.3.6Identify, in diagrams and images, the main blood vessels to and from the liver as: hepatic artery, hepatic veins and hepatic portal vein

4. Blood

9.4.1List the components of blood as: red blood cells, white blood cells, platelets and plasma
9.4.2Identify red and white blood cells in photomicrographs and diagrams
9.4.3
State the functions of the following components of blood: including the role of haemoglobin antibody production nutrients, urea, hormones and carbon dioxide:
- (a) red blood cells in transporting oxygen,
- (b) white blood cells in phagocytosis and
- (c) platelets in clotting (details are not required)
- (d) plasma in the transport of blood cells, ions,
9.4.4State the roles of blood clotting as preventing blood loss and the entry of pathogens
9.4.5Identify lymphocytes and phagocytes in photomicrographs and diagrams
9.4.6
State the functions of: phagocytosis:
- (a) lymphocytes – antibody production
- (b) phagocytes – engulfing pathogens by
9.4.7Describe the process of clotting as the conversion of fibrinogen to fibrin to form a mesh

10. Diseases and immunity

1. Diseases and immunity

10.1.1Describe a pathogen as a disease-causing organism
10.1.2Describe a transmissible disease as a disease in which the pathogen can be passed from one host to another
10.1.3
State that a pathogen is transmitted: and other body fluids surfaces, food, animals and air:
- (a) by direct contact, including through blood
- (b) indirectly, including from contaminated
10.1.4Describe the body defences, limited to: skin, hairs in the nose, mucus, stomach acid and white blood cells
10.1.5
Explain the importance of the following in controlling the spread of disease: sewage treatment are not required):
- (a) a clean water supply
- (b) hygienic food preparation
- (c) good personal hygiene
- (d) waste disposal
- (e) sewage treatment (details of the stages of
10.1.6Describe active immunity as defence against a pathogen by antibody production in the body
10.1.7State that each pathogen has its own antigens, which have specific shapes
10.1.8Describe antibodies as proteins that bind to antigens leading to direct destruction of pathogens or marking of pathogens for destruction by phagocytes
10.1.9State that specific antibodies have complementary shapes which fit specific antigens
10.1.10Explain that active immunity is gained after an infection by a pathogen or by vaccination
10.1.11
Outline the process of vaccination: put into the body by lymphocytes which produce antibodies long-term immunity:
- (a) weakened pathogens or their antigens are
- (b) the antigens stimulate an immune response
- (c) memory cells are produced that give
10.1.12Explain the role of vaccination in controlling the spread of diseases
10.1.13Explain that passive immunity is a short-term defence against a pathogen by antibodies acquired from another individual, including across the placenta and in breast milk
10.1.14Explain the importance of breast-feeding for the development of passive immunity in infants
10.1.15State that memory cells are not produced in passive immunity continued
10.1.16Describe cholera as a disease caused by a bacterium which is transmitted in contaminated water
10.1.17Explain that the cholera bacterium produces a toxin that causes secretion of chloride ions into the small intestine, causing osmotic movement of water into the gut, causing diarrhoea, dehydration and loss of ions from the blood

11. Gas exchange in humans

1. Gas exchange in humans

11.1.1Describe the features of gas exchange surfaces in humans, limited to: large surface area, thin surface, good blood supply and good ventilation with air
11.1.2Identify in diagrams and images the following parts of the breathing system: lungs, diaphragm, ribs, intercostal muscles, larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries
11.1.3Investigate the differences in composition between inspired and expired air using limewater as a test for carbon dioxide
11.1.4Describe the differences in composition between inspired and expired air, limited to: oxygen, carbon dioxide and water vapour
11.1.5Investigate and describe the effects of physical activity on the rate and depth of breathing
11.1.6Identify in diagrams and images the internal and external intercostal muscles
11.1.7State the function of cartilage in the trachea
11.1.8Explain the role of the ribs, the internal and external intercostal muscles and the diaphragm in producing volume and pressure changes in the thorax leading to the ventilation of the lungs
11.1.9Explain the differences in composition between inspired and expired air
11.1.10Explain the link between physical activity and the rate and depth of breathing in terms of: an increased carbon dioxide concentration in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing
11.1.11Explain the role of goblet cells, mucus and ciliated cells in protecting the breathing system from pathogens and particles

12. Respiration

1. Respiration

12.1.1State the uses of energy in living organisms, including: muscle contraction, protein synthesis, cell division, active transport, growth, the passage of nerve impulses and the maintenance of a constant body temperature
12.1.2Investigate and describe the effect of temperature on respiration in yeast

2. Aerobic respiration

12.2.1Describe aerobic respiration as the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy
12.2.2State the word equation for aerobic respiration as: glucose + oxygen → carbon dioxide + water
12.2.3State the balanced chemical equation for aerobic respiration as: C H O + 6O → 6CO + 6H O

3. Anaerobic respiration

12.3.1Describe anaerobic respiration as the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
12.3.2State that anaerobic respiration releases much less energy per glucose molecule than aerobic respiration
12.3.3State the word equation for anaerobic respiration in yeast as: glucose → alcohol + carbon dioxide
12.3.4State the word equation for anaerobic respiration in muscles during vigorous exercise as: glucose → lactic acid
12.3.5State the balanced chemical equation for anaerobic respiration in yeast as: C H O → 2C H OH + 2CO
12.3.612 6 2 5 2 blood during vigorous exercise causing an oxygen debt continued
12.3.7
Outline how the oxygen debt is removed after exercise, limited to: lactic acid in the blood from the muscles to the liver to supply oxygen for aerobic respiration of lactic acid:
- (a) continuation of fast heart rate to transport
- (b) continuation of deeper and faster breathing
- (c) aerobic respiration of lactic acid in the liver

13. Excretion in humans

1. Excretion in humans

13.1.1State that carbon dioxide is excreted through the lungs
13.1.2State that the kidneys excrete urea and excess water and ions
13.1.3Identify in diagrams and images the kidneys, ureters, bladder and urethra
13.1.4Identify in diagrams and images the structure of the kidney, limited to the cortex and medulla
13.1.5
Outline the structure and function of a nephron and its associated blood vessels, limited to: from the blood of water, glucose, urea and ions all of the glucose, some of the ions and most of the water back into the blood excess water and excess ions (details of these processes are not required):
- (a) the role of the glomerulus in the filtration
- (b) the role of the nephron in the reabsorption of
- (c) the formation of urine containing urea,
13.1.6Describe the role of the liver in the assimilation of amino acids by converting them to proteins
13.1.7State that urea is formed in the liver from excess amino acids
13.1.8Describe deamination as the removal of the nitrogen-containing part of amino acids to form urea
13.1.9Explain the importance of excretion, limited to toxicity of urea

14. Coordination and response

1. Coordination and response

14.1.1State that electrical impulses travel along neurones
14.1.2
Describe the mammalian nervous system in terms of: of the brain and the spinal cord consisting of the nerves outside of the brain and spinal cord:
- (a) the central nervous system (CNS) consisting
- (b) the peripheral nervous system (PNS)
14.1.3Describe the role of the nervous system as coordination and regulation of body functions
14.1.4Identify in diagrams and images sensory, relay and motor neurones
14.1.5Describe a simple reflex arc in terms of: receptor, sensory neurone, relay neurone, motor neurone and effector
14.1.6Describe a reflex action as a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands)
14.1.7Describe a synapse as a junction between two neurones
14.1.8Describe the structure of a synapse, including the presence of vesicles containing neurotransmitter molecules, the synaptic gap and receptor proteins
14.1.9
Describe the events at a synapse as: neurotransmitter molecules from vesicles into the synaptic gap across the gap receptor proteins on the next neurone neurone:
- (a) an impulse stimulates the release of
- (b) the neurotransmitter molecules diffuse
- (c) neurotransmitter molecules bind with
- (d) an impulse is then stimulated in the next
14.1.10State that synapses ensure that impulses travel in one direction only

2. Sense organs

14.2.1Describe sense organs as groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
14.2.2Identify in diagrams and images the structures of the eye, limited to: cornea, iris, pupil, lens, retina, optic nerve and blind spot
14.2.3
Describe the function of each part of the eye, limited to: pupil sensitive to light of different colours:
- (a) cornea – refracts light
- (b) iris – controls how much light enters the
- (c) lens – focuses light on to the retina
- (d) retina – contains light receptors, some
- (e) optic nerve – carries impulses to the brain
14.2.4Explain the pupil reflex, limited to changes in light intensity and pupil diameter
14.2.5Explain the pupil reflex in terms of the antagonistic action of circular and radial muscles in the iris
14.2.6Explain accommodation to view near and distant objects in terms of the contraction and relaxation of the ciliary muscles, tension in the suspensory ligaments, shape of the lens and refraction of light
14.2.7Describe the distribution of rods and cones in the retina of a human
14.2.8
Outline the function of rods and cones, limited to: of different colours, for colour vision:
- (a) greater sensitivity of rods for night vision
- (b) three different kinds of cones, absorbing light
14.2.9Identify in diagrams and images the position of the fovea and state its function

3. Hormones

14.3.1Describe a hormone as a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs
14.3.2
Identify in diagrams and images specific endocrine glands and state the hormones they secrete, limited to:
- (a) adrenal glands and adrenaline
- (b) pancreas and insulin
- (c) testes and testosterone
- (d) ovaries and oestrogen
14.3.3
Describe adrenaline as the hormone secreted in ‘fight or flight’ situations and its effects, limited to:
- (a) increased breathing rate
- (b) increased heart rate
- (c) increased pupil diameter
14.3.4Compare nervous and hormonal control, limited to speed of action and duration of effect
14.3.5State that glucagon is secreted by the pancreas
14.3.6
Describe the role of adrenaline in the control of metabolic activity, limited to:
- (a) increasing the blood glucose concentration
- (b) increasing heart rate

4. Homeostasis

14.4.1Describe homeostasis as the maintenance of a constant internal environment
14.4.2State that insulin decreases blood glucose concentration
14.4.3Explain the concept of homeostatic control by negative feedback with reference to a set point
14.4.4Describe the control of blood glucose concentration by the liver and the roles of insulin and glucagon
14.4.5Outline the treatment of Type 1 diabetes
14.4.6Identify in diagrams and images of the skin: hairs, hair erector muscles, sweat glands, receptors, sensory neurones, blood vessels and fatty tissue
14.4.7Describe the maintenance of a constant internal body temperature in mammals in terms of: insulation, sweating, shivering and the role of the brain
14.4.8Describe the maintenance of a constant internal body temperature in mammals in terms of vasodilation and vasoconstriction of arterioles supplying skin surface capillaries

5. Tropic responses

14.5.1Describe gravitropism as a response in which parts of a plant grow towards or away from gravity
14.5.2Describe phototropism as a response in which parts of a plant grow towards or away from the direction of the light source
14.5.3Investigate and describe gravitropism and phototropism in shoots and roots
14.5.4Explain phototropism and gravitropism of a shoot as examples of the chemical control of plant growth
14.5.5
Explain the role of auxin in controlling shoot growth, limited to: shoot tip light and gravity:
- (a) auxin is made in the shoot tip
- (b) auxin diffuses through the plant from the
- (c) auxin is unequally distributed in response to
- (d) auxin stimulates cell elongation

15. Drugs

1. Drugs

15.1.1Describe a drug as any substance taken into the body that modifies or affects chemical reactions in the body
15.1.2Describe the use of antibiotics for the treatment of bacterial infections
15.1.3State that some bacteria are resistant to antibiotics which reduces the effectiveness of antibiotics
15.1.4State that antibiotics kill bacteria but do not affect viruses
15.1.5Explain how using antibiotics only when essential can limit the development of resistant bacteria such as MRSA

16. Reproduction

1. Asexual reproduction

16.1.1Describe asexual reproduction as a process resulting in the production of genetically identical offspring from one parent
16.1.2Identify examples of asexual reproduction in diagrams, images and information provided
16.1.3
Discuss the advantages and disadvantages of asexual reproduction:
- (a) to a population of a species in the wild
- (b) to crop production

2. Sexual reproduction

16.2.1Describe sexual reproduction as a process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other
16.2.2Describe fertilisation as the fusion of the nuclei of gametes
16.2.3State that nuclei of gametes are haploid and that the nucleus of a zygote is diploid
16.2.4
Discuss the advantages and disadvantages of sexual reproduction:
- (a) to a population of a species in the wild
- (b) to crop production

3. Sexual reproduction in plants

16.3.1Identify in diagrams and images and draw the following parts of an insect-pollinated flower: sepals, petals, stamens, filaments, anthers, carpels, style, stigma, ovary and ovules
16.3.2State the functions of the structures listed in
16.3.3Identify in diagrams and images and describe the anthers and stigmas of a wind-pollinated flower
16.3.4Distinguish between the pollen grains of insect-pollinated and wind-pollinated flowers
16.3.5Describe pollination as the transfer of pollen grains from an anther to a stigma
16.3.6State that fertilisation occurs when a pollen nucleus fuses with a nucleus in an ovule
16.3.7Describe the structural adaptations of insect-pollinated and wind-pollinated flowers
16.3.8Investigate and describe the environmental conditions that affect germination of seeds, limited to the requirement for: water, oxygen and a suitable temperature
16.3.9Describe self-pollination as the transfer of pollen grains from the anther of a flower to the stigma of the same flower or a different flower on the same plant
16.3.10Describe cross-pollination as the transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species
16.3.11Discuss the potential effects of self-pollination and cross-pollination on a population, in terms of variation, capacity to respond to changes in the environment and reliance on pollinators continued
16.3.12Describe the growth of the pollen tube and its entry into the ovule followed by fertilisation (details of production of endosperm and development are not required)

4. Sexual reproduction in humans

16.4.1Identify on diagrams and state the functions of the following parts of the male reproductive system: testes, scrotum, sperm ducts, prostate gland, urethra and penis
16.4.2Identify on diagrams and state the functions of the following parts of the female reproductive system: ovaries, oviducts, uterus, cervix and vagina
16.4.3Describe fertilisation as the fusion of the nuclei from a male gamete (sperm) and a female gamete (egg cell)
16.4.4Explain the adaptive features of sperm, limited to: flagellum, mitochondria and enzymes in the acrosome
16.4.5Explain the adaptive features of egg cells, limited to: energy stores and the jelly coat that changes at fertilisation
16.4.6Compare male and female gametes in terms of: size, structure, motility and numbers
16.4.7State that in early development, the zygote forms an embryo which is a ball of cells that implants into the lining of the uterus
16.4.8Identify on diagrams and state the functions of the following in the development of the fetus: umbilical cord, placenta, amniotic sac and amniotic fluid
16.4.9Describe the function of the placenta and umbilical cord in relation to the exchange of dissolved nutrients, gases and excretory products between the blood of the mother and the blood of the fetus
16.4.10State that some pathogens and toxins can pass across the placenta and affect the fetus

5. Sexual hormones in humans

16.5.1Describe the roles of testosterone and oestrogen in the development and regulation of secondary sexual characteristics during puberty
16.5.2Describe the menstrual cycle in terms of changes in the ovaries and in the lining of the uterus
16.5.3Describe the sites of production of oestrogen and progesterone in the menstrual cycle and in pregnancy
16.5.4Explain the role of hormones in controlling the menstrual cycle and pregnancy, limited to FSH, LH, progesterone and oestrogen

6. Sexually transmitted infections

16.6.1Describe a sexually transmitted infection (STI) as an infection that is transmitted through sexual contact
16.6.2State that human immunodeficiency virus (HIV) is a pathogen that causes an STI
16.6.3State that HIV infection may lead to AIDS
16.6.4Describe the methods of transmission of HIV
16.6.5Explain how the spread of STIs is controlled

17. Inheritance

1. Chromosomes, genes and proteins

17.1.1State that chromosomes are made of DNA, which contains genetic information in the form of genes
17.1.2Define a gene as a length of DNA that codes for a protein
17.1.3Define an allele as an alternative form of a gene
17.1.4Describe the inheritance of sex in humans with reference to X and Y chromosomes
17.1.5State that the sequence of bases in a gene determines the sequence of amino acids used to make a specific protein (knowledge of the details of nucleotide structure is not required)
17.1.6Explain that different sequences of amino acids give different shapes to protein molecules continued
17.1.7Explain that DNA controls cell function by controlling the production of proteins, including enzymes, membrane carriers and receptors for neurotransmitters
17.1.8
Explain how a protein is made, limited to: the nucleus and move to the cytoplasm protein molecules determined by the sequence of bases in the mRNA (knowledge of the details of transcription or translation is not required):
- the gene coding for the protein remains in
- messenger RNA (mRNA) is a copy of a gene
- mRNA molecules are made in the nucleus
- the mRNA passes through ribosomes
- the ribosome assembles amino acids into
- the specific sequence of amino acids is
17.1.9Explain that most body cells in an organism contain the same genes, but many genes in a particular cell are not expressed because the cell only makes the specific proteins it needs
17.1.10Describe a haploid nucleus as a nucleus containing a single set of chromosomes
17.1.11Describe a diploid nucleus as a nucleus containing two sets of chromosomes
17.1.12State that in a diploid cell, there is a pair of each type of chromosome and in a human diploid cell there are 23 pairs

2. Mitosis

17.2.1Describe mitosis as nuclear division giving rise to genetically identical cells (details of the stages of mitosis are not required)
17.2.2State the role of mitosis in growth, repair of damaged tissues, replacement of cells and asexual reproduction
17.2.3State that the exact replication of chromosomes occurs before mitosis
17.2.4State that during mitosis, the copies of chromosomes separate, maintaining the chromosome number in each daughter cell Describe stem cells as unspecialised cells that divide by mitosis to produce daughter cells that can become specialised for specific functions

3. Meiosis

17.3.1State that meiosis is involved in the production of gametes
17.3.2Describe meiosis as a reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells (details of the stages of meiosis are not required)

4. Monohybrid inheritance

17.4.1Describe inheritance as the transmission of genetic information from generation to generation
17.4.2Describe genotype as the genetic make-up of an organism and in terms of the alleles present
17.4.3Describe phenotype as the observable features of an organism
17.4.4Describe homozygous as having two identical alleles of a particular gene
17.4.5State that two identical homozygous individuals that breed together will be pure-breeding
17.4.6Describe heterozygous as having two different alleles of a particular gene
17.4.7State that a heterozygous individual will not be pure-breeding
17.4.8Describe a dominant allele as an allele that is expressed if it is present in the genotype
17.4.9Describe a recessive allele as an allele that is only expressed when there is no dominant allele of the gene present in the genotype
17.4.10Interpret pedigree diagrams for the inheritance of a given characteristic
17.4.11Use genetic diagrams to predict the results of monohybrid crosses and calculate phenotypic ratios, limited to 1 : 1 and 3 : 1 ratios
17.4.12Use Punnett squares in crosses which result in more than one genotype to work out and show the possible different genotypes
17.4.13Explain how to use a test cross to identify an unknown genotype continued
17.4.14Describe codominance as a situation in which both alleles in heterozygous organisms contribute to the phenotype
17.4.15Explain the inheritance of ABO blood groups: phenotypes are A, B, AB and O blood groups and alleles are I , I and I
17.4.16Describe a sex-linked characteristic as a feature in which the gene responsible is located on a sex chromosome and that this makes the characteristic more common in one sex than in the other
17.4.17Describe red-green colour blindness as an example of sex linkage
17.4.18Use genetic diagrams to predict the results of monohybrid crosses involving codominance or sex linkage and calculate phenotypic ratios

18. Variation and selection

1. Variation

18.1.1Describe variation as differences between individuals of the same species
18.1.2State that continuous variation results in a range of phenotypes between two extremes; examples include body length and body mass
18.1.3State that discontinuous variation results in a limited number of phenotypes with no intermediates; examples include ABO blood groups, seed shape in peas and seed colour in peas
18.1.4State that discontinuous variation is usually caused by genes only and continuous variation is caused by both genes and the environment
18.1.5Investigate and describe examples of continuous and discontinuous variation
18.1.6Describe mutation as genetic change
18.1.7State that mutation is the way in which new alleles are formed
18.1.8State that ionising radiation and some chemicals increase the rate of mutation
18.1.9Describe gene mutation as a random change in the base sequence of DNA
18.1.10State that mutation, meiosis, random mating and random fertilisation are sources of genetic variation in populations

2. Adaptive features

18.2.1Describe an adaptive feature as an inherited feature that helps an organism to survive and reproduce in its environment
18.2.2Interpret images or other information about a species to describe its adaptive features
18.2.3Explain the adaptive features of hydrophytes and xerophytes to their environments

3. Selection

18.3.1
Describe natural selection with reference to: for resources individuals that are better adapted to the environment than others next generation:
- (a) genetic variation within populations
- (b) production of many offspring
- (c) struggle for survival, including competition
- (d) a greater chance of reproduction by
- (e) these individuals pass on their alleles to the
18.3.2
Describe selective breeding with reference to: desirable features next generation features:
- (a) selection by humans of individuals with
- (b) crossing these individuals to produce the
- (c) selection of offspring showing the desirable
18.3.3Outline how selective breeding by artificial selection is carried out over many generations to improve crop plants and domesticated animals and apply this to given contexts
18.3.4Describe adaptation as the process, resulting from natural selection, by which populations become more suited to their environment over many generations
18.3.5Describe the development of strains of antibiotic resistant bacteria as an example of natural selection
18.3.6Outline the differences between natural and artificial selection

19. Organisms and their environment

1. Energy flow

19.1.1State that the Sun is the principal source of energy input to biological systems
19.1.2Describe the flow of energy through living organisms, including light energy from the Sun and chemical energy in organisms, and its eventual transfer to the environment

2. Food chains and food webs

19.2.1Describe a food chain as showing the transfer of energy from one organism to the next, beginning with a producer
19.2.2Construct and interpret simple food chains
19.2.3Describe a food web as a network of interconnected food chains and interpret food webs
19.2.4Describe a producer as an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
19.2.5Describe a consumer as an organism that gets its energy by feeding on other organisms
19.2.6State that consumers may be classed as primary, secondary, tertiary and quaternary according to their position in a food chain
19.2.7Describe a herbivore as an animal that gets its energy by eating plants
19.2.8Describe a carnivore as an animal that gets its energy by eating other animals
19.2.9Describe a decomposer as an organism that gets its energy from dead or waste organic material
19.2.10Use food chains and food webs to describe the impact humans have through overharvesting of food species and through introducing foreign species to a habitat
19.2.11Draw, describe and interpret pyramids of numbers and pyramids of biomass
19.2.12Discuss the advantages of using a pyramid of biomass rather than a pyramid of numbers to represent a food chain
19.2.13Describe a trophic level as the position of an organism in a food chain, food web or ecological pyramid
19.2.14Identify the following as the trophic levels in food webs, food chains and ecological pyramids: producers, primary consumers, secondary consumers, tertiary consumers and quaternary consumers
19.2.15Draw, describe and interpret pyramids of energy
19.2.16Discuss the advantages of using a pyramid of energy rather than pyramids of numbers or biomass to represent a food chain continued
19.2.17Explain why the transfer of energy from one trophic level to another is often not efficient
19.2.18Explain, in terms of energy loss, why food chains usually have fewer than five trophic levels
19.2.19Explain why it is more energy efficient for humans to eat crop plants than to eat livestock that have been fed on crop plants

3. Nutrient cycles

19.3.1Describe the carbon cycle, limited to: photosynthesis, respiration, feeding, decomposition, formation of fossil fuels and combustion
19.3.2
Describe the nitrogen cycle with reference to: ammonium ions:
- decomposition of plant and animal protein to
- nitrification
- nitrogen fixation by lightning and bacteria
- absorption of nitrate ions by plants
- production of amino acids and proteins
- feeding and digestion of proteins
- deamination
- denitrification
19.3.3State the roles of microorganisms in the nitrogen cycle, limited to: decomposition, nitrification, nitrogen fixation and denitrification (generic names of individual bacteria, e.g. Rhizobium , are not required)

4. Populations

19.4.1Describe a population as a group of organisms of one species, living in the same area, at the same time
19.4.2Describe a community as all of the populations of different species in an ecosystem
19.4.3Describe an ecosystem as a unit containing the community of organisms and their environment, interacting together
19.4.4Identify and state the factors affecting the rate of population growth for a population of an organism, limited to food supply, competition, predation and disease
19.4.5Identify the lag, exponential (log), stationary and death phases in the sigmoid curve of population growth for a population growing in an environment with limited resources
19.4.6Interpret graphs and diagrams of population growth
19.4.7Explain the factors that lead to each phase in the sigmoid curve of population growth, making reference, where appropriate, to the role of limiting factors

20. Human influences on ecosystems

1. Food supply

20.1.1
Describe how humans have increased food production, limited to: land and improve efficiency crop plants and livestock:
- (a) agricultural machinery to use larger areas of
- (b) chemical fertilisers to improve yields
- (c) insecticides to improve quality and yield
- (d) herbicides to reduce competition with weeds
- (e) selective breeding to improve production by
20.1.2Describe the advantages and disadvantages of large-scale monocultures of crop plants
20.1.3Describe the advantages and disadvantages of intensive livestock production

2. Habitat destruction

20.2.1Describe biodiversity as the number of different species that live in an area
20.2.2
Describe the reasons for habitat destruction, including: production and livestock production:
- (a) increased area for housing, crop plant
- (b) extraction of natural resources
- (c) freshwater and marine pollution
20.2.3State that through altering food webs and food chains, humans can have a negative impact on habitats
20.2.4Explain the undesirable effects of deforestation as an example of habitat destruction, to include: reducing biodiversity, extinction, loss of soil, flooding and increase of carbon dioxide in the atmosphere

3. Pollution

20.3.1Describe the effects of untreated sewage and excess fertiliser on aquatic ecosystems
20.3.2Describe the effects of non-biodegradable plastics, in both aquatic and terrestrial ecosystems
20.3.3Describe the sources and effects of pollution of the air by methane and carbon dioxide, limited to: the enhanced greenhouse effect and climate change
20.3.4
Explain the process of eutrophication of water, limited to: ions producers oxygen in water:
- increased availability of nitrate and other
- increased growth of producers
- increased decomposition after death of
- increased aerobic respiration by decomposers
- reduction in dissolved oxygen
- death of organisms requiring dissolved

4. Conservation

20.4.1Describe a sustainable resource as one which is produced as rapidly as it is removed from the environment so that it does not run out
20.4.2State that some resources can be conserved and managed sustainably, limited to forests and fish stocks
20.4.3Explain why organisms become endangered or extinct, including: climate change, habitat destruction, hunting, overharvesting, pollution and introduced species
20.4.4
Describe how endangered species can be conserved, limited to: habitats:
- (a) monitoring and protecting species and
- (b) education
- (c) captive breeding programmes
- (d) seed banks
20.4.5Explain how forests can be conserved using: education, protected areas, quotas and replanting
20.4.6Explain how fish stocks can be conserved using: education, closed seasons, protected areas, controlled net types and mesh size, quotas and monitoring
20.4.7
Describe the reasons for conservation programmes, limited to: to nutrient cycling and resource provision, including food, drugs, fuel and genes:
- (a) maintaining or increasing biodiversity
- (b) reducing extinction
- (c) protecting vulnerable ecosystems
- (d) maintaining ecosystem functions, limited
20.4.8Describe the use of artificial insemination (AI) and in vitro fertilisation (IVF) in captive breeding programmes
20.4.9Explain the risks to a species if its population size decreases, reducing genetic variation (knowledge of genetic drift is not required)

21. Biotechnology and genetic modification

1. Biotechnology and genetic modification

21.1.1State that bacteria are useful in biotechnology and genetic modification due to their rapid reproduction rate and their ability to make complex molecules
21.1.2
Discuss why bacteria are useful in biotechnology and genetic modification, limited to: and growth:
- (a) few ethical concerns over their manipulation
- (b) the presence of plasmids

2. Biotechnology

21.2.1Describe the role of anaerobic respiration in yeast during the production of ethanol for biofuels
21.2.2Describe the role of anaerobic respiration in yeast during bread-making
21.2.3Describe the use of pectinase in fruit juice production
21.2.4Investigate and describe the use of biological washing powders that contain enzymes
21.2.5Explain the use of lactase to produce lactose-free milk
21.2.6Describe how fermenters can be used for the large-scale production of useful products by bacteria and fungi, including insulin, penicillin and mycoprotein
21.2.7Describe and explain the conditions that need to be controlled in a fermenter, including: temperature, pH, oxygen, nutrient supply and waste products

3. Genetic modification

21.3.1Describe genetic modification as changing the genetic material of an organism by removing, changing or inserting individual genes
21.3.2
Outline examples of genetic modification: produce human proteins confer resistance to herbicides confer resistance to insect pests improve nutritional qualities:
- (a) the insertion of human genes into bacteria to
- (b) the insertion of genes into crop plants to
- (c) the insertion of genes into crop plants to
- (d) the insertion of genes into crop plants to
21.3.3
Outline the process of genetic modification using bacterial production of a human protein as an example, limited to: gene using restriction enzymes, forming sticky ends the same restriction enzymes, forming complementary sticky ends plasmid DNA using DNA ligase to form a recombinant plasmid bacteria (specific details are not required) recombinant plasmids make the human protein continued:
- (a) isolation of the DNA making up a human
- (b) cutting of bacterial plasmid DNA with
- (c) insertion of human DNA into bacterial
- (d) insertion of recombinant plasmids into
- (e) multiplication of bacteria containing
- (f) expression in bacteria of the human gene to
21.3.4Discuss the advantages and disadvantages of genetically modifying crops, including soya, maize and rice