Truth in Science

Rationale

The WJEC specification is intended to define a body of knowledge and skills which is considered essential to the study of biology at this level. It provides a broad view of all the major aspects of the subject and an appreciation of their interdependence. The breadth of study and updated content will enable the implications of modern biology to be appreciated and the importance of the role of these studies in understanding environmental, ethical and social issues and their implications. An understanding of scientific method as the means by which the body of scientific knowledge is increased and an enquiring and critical approach is to be fostered, including an awareness that different perceptions, predictions and interpretations may be applied according to context. The practical work serves to illustrate and to promote an investigatory approach. The use of computer technology such as CD-Roms, the Internet and computer simulations is encouraged. It is intended that the use of a variety of approaches will stimulate interest, promote understanding and engender an overall appreciation and sense of wonder at the living world.

 

The broad objectives therefore are:

• to provide a broad factual base and skills
• to stimulate an interest in the subject
• to facilitate a critical appreciation of issues arising from the subject.

The specification provides a framework and includes specific content through which individual courses may address spiritual, moral, ethical, social and cultural issues.

Specific relevant subject content includes:

5.2 Evolution and natural selection; loss of biodiversity.

 

Sensitive Issues

It should also be noted that some aspects of the specification may raise contentious issues e.g. evolution which should be treated with understanding.

Assessment Unit BI5: Variety and Control

Summary

Unit BI5 involves the study of variation and evolution plus sensitivity: reproduction; variation; genetics; evolution and diversity; homeostasis; nervous system.

5.1 All organisms are variable in form and function.

(a) Alleles as different forms of the same gene. An understanding of the principles of monohybrid and dihybrid Mendelian inheritance. Codominance (Monohybrid only). Sex linkage as illustrated by haemophilia.

(b) Gene mutation as illustrated by sickle cell anaemia and chromosome mutation as illustrated by Down's syndrome. Mutagens and carcinogens. Random assortment, crossing over and fertilisation as sources of variation.  Practical Activities: One experiment to illustrate gene segregation (Drosophila, maize cobs and tomato plants are suitable, but other material may be used).

5.2 Genetic variation is the raw material for evolutionary change.

(a) Genetic and environmental factors produce variation between individuals. Variation - continuous and discontinuous; heritable and non-heritable. Practical Activities: Investigation of continuous variation in a locally occurring species including use of students t test e.g. comparison of florets on north and south facing Ivy or wing length in fruits of Sycamore (t test will only be examined through the practical assessment). Inter and intra-specific competition for breeding success and survival. Selective agencies (e.g. supply of food, breeding sites, climate). The gene pool and genetic drift. Selection can change the frequency of alleles in a population.

(b) Isolation and speciation. Separation of populations by geographical, behavioural, morphological seasonal and isolation mechanisms. Hybrid sterility. Darwin's theory of evolution that existing species have arisen through modification of ancestral species by natural selection. The formation of new species as illustrated by Darwin's finches. Ancestral species evolved by adaptive radiation to occupy vacant niches, free from competition, in the Galapagos islands.

(c) Human influence on the environment has created new selection pressures as illustrated by warfarin resistance in rats, and antibiotic resistant forms of bacteria. Artificial selection. Biodiversity. Reasons for species becoming endangered and causes of extinction. The conservation of gene pools in the wild and in captivity. Practical Activities: Investigation of endangered species using secondary sources (ICT is suitable).

 

5.6 Species are classified into groups using shared derived features.

(a) Characteristic features of Kingdoms:- Prokaryotae, Protoctista, Plantae, Fungi, Animalia.

(b) The concept of the species. The binomial system. The principle that modern classification should reflect closeness of evolutionary relations. The example of the Tiger should be used simply to illustrate the concept of each taxon and main features only.

Kingdom: Animalia; Phylum: Chordata; Class: Mammalia; Order:Carnivora; Family: Felidae; Genus: Panthera; Species: P. tigris.

Appendix 4. THE EXEMPLIFICATION OF KEY SKILLS

C2.2 INFORMATION GATHERING

Candidates must:	Evidence must show candidates can:	Examples of evidence:	Suggested context:
read and summarise information from two extended documents about a straightforward subject. One of the documents should include at least one image.	select and read relevant material identify accurately the lines of reasoning and main points from text and images summarise the information to suit the purpose.	A record of what is read and why, including a note or copy of the image. Notes, highlighted text or answers to questions about the material read. Evidence of summarising information could include the student’s notes for the talk, or one of the documents written.	Notes or annotations of different sources relating to a scientific topic e.g. fossil record as evidence for evolution.

COMMUNICATION: LEVEL 3

C3.1a TAKE PART IN A DISCUSSION

Candidates must:	Evidence must show candidates can:	Examples of evidence:	Suggested context:
contribute to a group discussion about a complex subject	make clear and relevant contributions listen and respond appropriately create opportunities for others to take part.	A record from someone who has observed discussion or has made video/ audio tape of discussion.	Discussion of controversial issues such as genetic engineering.

WIDER KEY SKILLS

PROBLEM SOLVING: LEVEL 1

PS 1.1 CONFIRM PROBLEMS AND IDENTIFY OPTIONS

Candidates must:	Evidence must show candidates can:	Examples of evidence:	Suggested context:
confirm understanding of the given problem and identify at least two options for solving it, with help from an appropriate person.	check that the problem is understood, and how to succeed in solving it identify different ways of tackling the problem decide, with help, which options are most likely to be successful.	Descriptions of the two problems and how they have been solved. Descriptions of ways for solving the two problems and the options most likely to be successful. Records of help given.	Students choose a Scientific topic for an extended essay or coursework study and make notes or essay plans considering two was of approaching it. This could involve group/class discussion of aspects/approaches and of possible sources of information (e.g. alternative ways of finding information). The topic might itself contain problems on which there are different Scientific perspectives.