Standard Grade Biology:
Course summary

Items in italic are for Credit level only.

1. The biosphere

a. Investigating an ecosystem

Parts of an ecosystem (habitat, animals, plants)
Sampling techniques; possible sources of error
Use of keys and checklists
Measuring abiotic factors; possible sources of error
Effect of abiotic factors on distribution of organisms and why

b. How it works

Habitats, communities, populations, and ecosystems.
Producers and consumers.
Food chains and food webs; the effect of removing organisms from food webs.
Energy flow through a food web; pyramids of numbers/biomass.
Population growth; birth/death rates; growth curves.
Factors limiting population growth.
Effects of competition.
Nutrient cycles; the nitrogen cycle.

c. Control and management

Pollution and its sources (domestic/agricultural/industrial); fossil fuels and nuclear energy.

Organic waste as food for micro-organisms depriving water of oxygen; indicator species.

Problems involving poor natural resource management; control of ecosystems in agriculture and forestry.

2. The world of plants

a. Introducing plants

The variety of plants; benefits of variety; consequences of loss of biodiversity.
Uses of plants by humans; production/refining processes; potential new uses.

b. Growing plants

Structure of dicotyledonous seed (embryo, seed coat, food store).
Effect of temperature, water availability and oxygen on germination.
Parts of flower (sepal, petal, stamen, anther, stigma, ovary, nectary); wind and insect pollinated flowers.
Pollination; growth of pollen tube; fertilisation (fusion of gametes); fruit formation.
Propagation by grafting and cuttings; clones.
Asexual reproduction by runners and tubers; advantages of sexual/asexual reproduction.

c. Making food

Movement of water and food in xylem and phloem; structure of xylem and phloem.
Uptake of carbon dioxide through stomata which can open and close; structure of leaf (mesophyll, epidermis, veins).
Loss of water vapour through stomata.
Making food which can be stored as starch; structural/storage carbohydrates and energy sources.
Conversion of light energy to chemical energy using chlorophyll.
Raw materials and products of photosynthesis; limiting factors.

3. Animal survival

a. The need for food

Why animals need food; simple structure of carbohydrates, proteins and fats.
Digestion (breakdown of large insoluble substances to small soluble ones) and absorption in intestine.
Types of teeth and mechanical breakdown of food in carnivore, herbivore and omnivore.
Parts of alimentary canal (mouth, salivary glands, oesophagus, stomach, pancreas, liver, gall bladder, small intestine, large intestine, appendix, rectum, anus); sites of digestive juice production; peristalsis; contractions of stomach.
Enzymatic breakdown of carbohydrates (by amylase), fats (by lipase) and proteins (by proteases).
Structure of small intestine; how a villus, with lacteal and capillaries, aids absorption.
Role of large intestine in water absorption and elimination.

b. Reproduction

Features of sperm and eggs.
Internal/external fertilisation in fish; importance of internal fertilisation in land animals.
Sperm production in testes; egg production in ovaries and fertilisation in oviducts.
Fish eggs with protective coverings and yolk; development of mammalian embryo; placenta.
Independent young of fish; dependent young of mammals.

c. Water and waste

How water is gained/lost.
Kidneys regulating water control; role of ADH.
Urinary system (kidney, renal arteries/veins, ureter, bladder); filtration of blood and reabsorption of useful substances; nephron structure (Bowman's capsule, glomerulus, blood capillaries, collecting duct); urea and its source.
Implications of kidney damage; artificial and replacement kidneys.

d. Responding to the environment

Responses to environmental factors and their significance.
Rhythmical behaviours triggered by external stimuli and their significance.

4. Investigating cells

a. Investigating living cells

Tissues made up of cells.
Studying cells under a microscope; use of staining.
Comparison of plant and animal cells.

b. Investigating diffusion

Diffusion of substances from high to low concentration and its importance.
Substances that diffuse in and out of cells, across cell membrane.
Osmosis (diffusion of water down concentration gradient across semi-permeable membrane) and its effects on cells.

c. Investigating cell division

Cells increase in number by division, controlled by the nucleus.
New cells containing same chromosome complement and why this is important.
Stages of mitosis and what happens at each.

d. Investigating enzymes

Why enzymes are needed; catalysts; specificity.
Examples of enzymes involved in breakdown/synthesis.
Enzymes as proteins; effect of temperature; effect of pH (on pepsin and amylase); optimum conditions.

e. Investigating aerobic respiration

Why organisms need energy; energy content of foods.
Word equation for aerobic respiration; need for oxygen.
Production of carbon dioxide (derived from food) in respiration.
Production of heat in respiration; importance of energy released during respiration for cell metabolism.

5. The body in action

a. Movement

The range of human activities.
Skeleton providing a framework for support and muscle attachment, and protection for vital organs.
Movements allowed by ball-and-socket/hinge joints; cartilage and ligaments; structure of synovial joint.
Bone composed of flexible fibres and hard minerals, produced by cells.
Muscles attached to bones by inelastic tendons.
Movement brought about by muscle contraction; opposing muscles.

b. The need for energy

Consequences of imbalance in energy input/output.
Composition of inhaled and exhaled air; oxygen absorbed and carbon dioxide released.
Structure of lungs; mechanism of breathing; function of cilia, cartilage and mucus; efficient gas exchange.
Four chambers of heart; path of blood flow; heart valves; thickness of ventricle walls; coronary arteries.
Blood flowing through arteries, capillaries and veins; pulse.
Red blood cells and plasma transporting respiratory gases and food; haemoglobin carrying oxygen.
Gas exchange between body cells and capillaries; how capillary networks allow efficient gas exchange.

c. Co-ordination

Co-ordination of movement during an activity.
Judgement of distance is more accurate using two eyes than one and why.
Structure of eye (cornea, iris, lens, retina, optic nerve).
Judgement of sound is more accurate using two ears than one.
Structure of ear (ear drum, middle ear bones, cochlea, auditory nerve, semi-circular canals); arrangement of semi-circular canals.
Nervous system composed of brain, spinal cord and nerves.
Nerves carry information from senses to CNS and from CNS to muscles; reflex arcs.
Parts of the brain (cerebrum, cerebellum, medulla).

d. Changing levels of performance

Muscle fatigue due to lack of oxygen and build up of lactic acid from anaerobic respiration.
Pulse rate and breathing rate increasing with exercise.
Pulse rate, breathing rate and lactic acid levels during exercise increase less in a trained athlete due to improved efficiency of lungs and circulation; recovery time as an indicator of fitness.

6. Inheritance

a. Variation

A species as a group of organisms that can interbreed to produce fertile offspring.
Variation within species.
Continuous and discontinuous variation.

b. What is inheritance?

Inherited characteristics.
Identifying examples of true-breeding, dominant and recessive characteristics from results of crosses.
P, F1 and F2 generations in a true-breeding cross; expected phenotypes of F1 and F2 generations.
Cells containing two sets of chromosomes; halving of chromosome number during gamete formation; how chromosome number is restored at fertilisation.
Genes as part of chromosomes; one version (allele) inherited from each parent; genotypes.
Sex chromosomes; male gametes having X or Y chromosome, female gametes having X chromosome.

c. Genetics and society

Examples of selective breeding to improve organisms (in both a plant and an animal).
Human conditions caused by mutations (e.g. Down’s syndrome); amniocentesis; advantageous mutations; factors influencing mutation rate.

7. Biotechnology

a. Living factories

Manufacture of dough, beer and wine depends on yeast, a single-celled fungus feeding on sugar.
Word equation for fermentation of glucose by yeast; comparison of aerobic and anaerobic respiration, optimum conditions for yeast growth; batch processing; need for malting of barley.
Manufacture of yoghurt depends on bacteria that sour milk by fermentation of lactose.

b. Problems and profit with waste

Disease and environmental damage caused by improper disposal of sewage.
Precautions taken when culturing micro-organisms to exclude resistant bacterial and fungal spores.
Role of bacteria in carbon and nitrogen cycles; decay due to feeding of micro-organisms.
Breakdown of sewage by a range of micro-organisms requiring oxygen.
Biotechnological methods of upgrading waste materials to improve protein or available energy content.
Alcohol and methane produced by fermentation; advantages of this over fossil fuels.
Rapid growth of micro-organisms under suitable conditions; harvesting of protein-rich food from them.

c. Re-programming microbes

Control of bacterial activity depends on chromosomal material.
Transfer of chromosomal material in genetic engineering allows bacteria to make new substances, increase or speed up yield of products; advantages of genetic engineering over selective breeding.
Biotechnological products in everyday use.
Products of genetic engineered bacteria, such as insulin and why it is needed.
Potential hazards of genetically engineering bacteria.
Low-temperature biological detergents, containing enzymes produced by bacteria, and their advantages.
Antibiotics preventing growth of micro-organisms and their use in treating disease.
Advantages of using immobilisation techniques to allow continuous-flow processing.

Required practical techniques

Using sampling techniques applicable to ecosystems.
Measuring one abiotic factor.
Measuring a different abiotic factor.
Using a simple biological key for living/preserved specimens.
Using a compound microscope with a low power objective lens.
Preparing a microscope slide as a wet mount.
Making a simple line drawing from a biological specimen.
Carrying out a test for starch.
Carrying out a test for reducing sugar.
Setting up a choice chamber.

Investigative skills

G1: demonstrate understanding of the problem posed;
G2: state the aim of the investigation (in terms of the two relevant variables);
G3: articulate a testable hypothesis (in terms of the two relevant variables; directional if a continuous variable is chosen);
G4: suggest a broad strategy to adopt (including how the independent variable will be altered, and what must be measured).

E1: adopt appropriate and safe procedures;
E2: identify the independent variable to be used and alter it over a suitable range;
E3: control all relevant variables as necessary;
E4: make valid, reliable measurement of the dependent variable (repeat/replicate testing if appropriate).

RR1: tabulate results with appropriate headings and units of measurement;
RR2: present the results on a graph or chart (with appropriate labels and units, and line of best fit if appropriate).
RR3: describe how the investigation was carried out (including labelled diagram or statement of apparatus, how dependent variable was measured, how independent variable was altered, how other variables were controlled).

Ev1: draw a valid conclusion inter-relating the appropriate variables (or state that no firm conclusion can be drawn);
Ev2: use results to evaluate the original hypothesis (confirm, or refute and replace, hypothesis).

Disclaimer: I cannot guarantee the accuracy of the information given here, and the syllabus may change in the future. For authoritative information about this course, see the Scottish Qualifications Authority web site.

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Standard Grade Biology: Course summary