The relationship between
photosynthesis and
respiration
Photosynthesis
as a process in which light energy is used in the synthesis of organic
molecules.
Respiration as
the process by which energy in organic molecules is made available for other
processes within an organism.
ATP The synthesis of ATP
from ADP and inorganic phosphate, and its role as the immediate source of
energy for biological processes.
Light-dependent
reaction The
light-dependent reaction only in sufficient detail to show that:
. light energy
excites electrons in chlorophyll;
. the energy
from these excited electrons is used to generate ATP and reduced NADP;
. photolysis of
water makes hydrogen available for the light-independent reaction and gaseous oxygen is released.
Light-independent
reaction The
light-independent reaction only in sufficient detail to show that:
. carbon dioxide
is accepted by ribulose bisphosphate to form two molecules of
glycerate-3-phosphate;
. ATP and
reduced NADP are required for the reduction of glycerate-3-phosphate to
carbohydrate;
. ribulose
bisphosphate is regenerated.
Chloroplast
structure The
structure and role of chloroplasts in relation to photosynthesis.
Glycolysis and Krebs
cycle The biochemistry of aerobic
respiration only in sufficient detail to show that:
. glycolysis
involves the oxidation of glucose to pyruvate with a net gain of ATP and
reduced NAD;
. pyruvate
combines with coenzyme A to produce acetylcoenzyme A;
. acetylcoenzyme
A is effectively a two-carbon molecule which combines with a four-carbon
molecule to produce a six-carbon molecule which enters Krebs cycle;
. Krebs cycle
involves a series of oxidation reactions and the release of carbon dioxide
leading to the production of ATP and reduced coenzyme (NAD or FAD);
. synthesis of
ATP is associated with the electron transport chain.
Mitochondria The
structure and role of mitochondria in respiration.
Stimulus and
Response Organisms
increase their chances of survival by responding to changes in their
environment.
Information is
transferred in the nervous system through detection of stimuli by receptors and
the initiation of a nerve impulse, leading to an associated response by
effectors by means of a coordinator.
A simple reflex
arc involving three neurones.
Information is
transferred by hormones released by endocrine glands and affecting the
physiological activities of target cells.
Homeostasis Physiological
control systems operate in mammals to maintain a constant internal
Negative feedback
The principle of
negative feedback and its role in restoring systems to their original levels.
Regulation of body
temperature
The processes
involved in thermoregulation in a mammal, includingthe role of thermoreceptors
in the skin and the hypothalamus.
Regulation of
blood sugar The role of insulin and
glucagon in the control of blood sugar, including the importance of specific
membrane receptors and their effect on enzyme-controlled reactions. The
conversion of glucose to glycogen for storage.
Removal of
metabolic waste
Waste products of metabolism are frequently toxic and must be removed from the
body.
Deamination of
excess amino acids and the production of urea. (Details of the ornithine cycle not
required.)
The processes
involved in the formation of urine in the kidney, including ultrafiltration in
the renal capsule and selective
reabsorption in the proximal convoluted tubule.
Regulation of
blood water
potential
The role of the
loop of Henle in maintaining a gradient of ions across the medulla.
The role of ADH
in the control of water by the distal convoluted tubule and the collecting
duct.
The importance
of the ionic gradient in regulating blood water potential.
The mammalian
eye The
structure and function of the iris in controlling the amount of light which
enters the eye.
The roles of the
cornea, lens, ciliary muscles and suspensory ligaments in focusing an image on
the retina.
Rods and cones The structure
of rods and cones.
The
photosensitive bleaching of rhodopsin in rods.
The trichromatic
theory of colour vision as an explanation of the functioning of cones.
Differences in
sensitivity and visual acuity as explained by differences in the distribution
of rods and cones and the connections they make with neurones in the optic
nerve.
impulse The
structure of a myelinated motor neurone.
The
establishment of a resting potential in terms of the differential membrane permeability
and the presence of cation pumps.
The initiation
of an action potential and its all-or-nothing nature, explained by changes in
membrane permeability leading to deplorisation.
The passage of
an action potential along non-myelinated and myelinated axons resulting in
nerve impulses.
The nature and
importance of the refractory period in producing
discrete nerve
impulses.
Synapses and synaptic
transmission
The detailed
structure of a synapse as revealed by an electron microscope.
The sequence of
events involved in the action of a cholinergic synapse and a neuromuscular
junction.
Drugs and
synapses The
effect of drugs on synaptic transmission.
When provided with information, candidates
should be able to
predict and explain the effects of specific
drugs on a synapse.
The brain and cerebral
hemispheres
The principal
functions of the cerebral hemispheres:
. the role of
sensory areas in receiving input from receptors and motor areas controlling
effectors;
. the relationship
between the size of the relevant part of the cerebral hemispheres and the
complexity of innervation;
. the control of
one side of the body by the opposite hemisphere;
. the role of
association areas in interpreting sensory input as illustrated by the visual
association area;
. the location
and role of areas of the cerebral hemispheres associated with speech.
The autonomic nervous
system
The general role
of the sympathetic and parasympathetic components of the autonomic nervous
system.
The specific effects
of the autonomic nervous system on controlling:
. pupil diameter
and tear production in the eye;
. the emptying
of the bladder.
8 Muscles are effectors
which enable movement to
be carried out
Antagonistic
muscle action Candidates should be able to
explain examples of movement in terms of antagonistic muscle action.
Muscle structure The
structure of skeletal muscle as seen with light and electron microscopes.
The relationship
between the structure of a sarcomere and the distribution of actin and myosin.
Muscle
contraction The sliding filament hypothesis of muscle contraction.
The role of
tropomyosin, calcium ions and ATP in the cycle of actomyosin bridge formation.
Candidates should be able to relate the mechanism of muscle
contraction to the appearance of a
sarcomere in a contracted or a
relaxed state.
Genotype The genotype is the genetic
constitution of an organism.
The expression of this genetic
constitution and its interaction with the
environment is the phenotype.
The alleles at a specific locus may be
either homozygous or
heterozygous. Alleles may be dominant,
recessive or codominant.
There may be multiple alleles of a single
gene.
Meiosis and fertilisation The principal
events associated with meiosis, to include:
. pairing by homologous chromosomes;
. formation of bivalents;
. chiasma formation and exchange between
chromatids;
. separation of chromatids;
. production of
haploid cells.
Candidates should be able to explain:
the behaviour of alleles and homologous
chromosomes during meiosis and fertilisation, i.e. independent assortment
during meiosis and random recombination during fertilisation;
the random movement of non-homologous
chromosomes and non allelic genes.
(Details and names of individual stages of
meiosis are not required.)
Sex determination The genetic basis of sex
determination.
Monohybrid and dihybrid inheritance
Candidates should be able to apply the above principles to
interpret and use fully annotated genetic
diagrams to predict the
results of:
. monohybrid crosses involving dominant,
recessive and
codominant alleles;
. crosses involving sex-linked
characteristics;
. dihybrid crosses, including epistasis.
Types of
variation Variation
between individuals may be either continuous or discontinuous.
Causes of
variation Similarities and differences
between individuals within a species may be the result of genetic factors, differences in environmental
factors, or a combination of both.
Candidates should be able to interpret data to determine the relative
effects of genetic and environmental factors involved in continuous and
discontinuous variation.
Candidates should be able to explain how crossing over, independent
assortment of chromosomes, random fusion of gametes and mutation contribute to
genetic variation.
Natural selection Individuals within a
species may show a wide range of variation.
Predation, disease and competition result
in differential survival and reproduction. Those organisms with a selective advantage
are more likely to survive, reproduce and pass on their genes to the next
generation.
Candidates should be able to:
. use specific examples to explain how
natural selection produces changes within a species;
. interpret data and use unfamiliar information
to explain how natural selection produces change within a population.
Speciation The concept of the species in
terms of production of fertile offspring.
Candidates should be able to explain:
. how natural selection and isolation may
result in changes in the allele and phenotype frequency and lead to the
formation of a new species;
. how evolutionary change over a long
period of time has resulted in a great diversity of forms among living
organisms.
Principles of
taxonomy The
principles and importance of taxonomy.
A classification
system comprises a hierarchy in which groups are contained within larger
composite groups with no overlap.
The phylogenetic
groupings are based on patterns of evolutionary history.
The five kingdoms
One hierarchy comprises Kingdom, Phylum, Class, Order, Family, Genus, Species.
The
distinguishing features of the five kingdoms – prokaryotes, protoctists, fungi,
plants and animals.