GCSEmodule2

GCSE Science B (Modular)
Science: Single Award B (1535)
Science: Double Award B (1536)
Biology B (1529)

Module 2 - Inheritance and survival

Introduction

The content of this module may be conveniently divided into four areas of study.

1. Chromosomes and variation

2. Genes and variation; genetically modified organisms

3. Selection, survival and evolution

4. Pollution and human survival

Module 2 - Inheritance and survival
Scheme of lessons
Lesson Title Comments
1 Basic genetics Leading on from KS3 prior knowledge
2 Mitosis and meiosis Higher tier only
3 Variation I
4 Variation II
5 The inheritance of sex
6 Hormones
7 The double helix
8 Looking at human DNA some Higher tier; restriction enzymes and ethics
9 Ideas and evidence
10 Monohybrid inheritance
11 Mutation
12 Genetic modification
13 Human genome project
14 Adaptation to environment
15 Populations
16 Evolution
17 Artificial selection
18 Pollution

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 Lesson 1 Basic genetics.

National Curriculum Statements.

4a how variation arises from genetic causes, environmental causes and a combination of both
4b that sexual reproduction is a source of genetic variation, while asexual reproduction produces clones
Specification Objectives

recall that each human body cell contains 23 pairs of chromosomes giving a diploid number of 46

recall that each human gamete contains 23 chromosomes, the haploid number

describe how the fusion of haploid male and female gametes (fertilisation) produces a diploid zygote (fertilised ovum or egg cell)
describe how asexual reproduction leads to genetically identical individuals (clones)

Key words: chromosome, diploid, haploid, zygote, asexual, sexual

Lesson Content

Revise KS3 cell structure particularly the presence and role of the nucleus.

Students study micrographs of sets of human chromosomes in the nuclei of various body cells and of sperm cells and ova. Use video camera and microscope.

Use chromosome worksheet.

Discuss the result of fertilisation - a diploid zygote in which one of each pair of chromosomes comes from the mother and one from the father.

Compare sexual with asexual reproduction and show how asexual reproduction leads to identical individuals (clones). Look at spider plants and other asexual plants.

LIVING WORLD p222-5, p238-9.
STG p48-9.
Video 128 genetics.

Homework/extension work.
Nelson Modular Science I: p40-4.

Notes / Resources

Micrographs of human chromosomes
Differentiation:
- Simple counting of chromosomes to give 46.
- Searching for some obvious pairs (eg 1,2,21,22,XX) using female micrographs.
- Producing a full karyogram.
Chromosome worksheet. 10/2/1.
Video 128 genetics.
Spider plants and other asexually reproducing plants.
This idea will be taken up again when asexual reproduction in bacteria is discussed.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 2 - Mitosis and meiosis

National Curriculum Statements.

4a how variation arises from genetic causes, environmental causes and a combination of both,
4b that sexual reproduction is a source of genetic variation, while asexual reproduction produces clones
Specification Objectives

understand that mitosis is the division of a cell to produce two cells with identical sets of chromosomes, for growth or replacement
describe the outcome of mitosis - the replication of each chromosome and the separation of the replicas (recall or use of technical terms is not required)

understand that meiosis is the division of a diploid cell to produce four haploid cells with sets of chromosomes that are not genetically identical to produce gametes (sperm and ovum) (recall or use of technical terms is not required)

Key words: mitosis, chromosome, meiosis, diploid, haploid

Lesson Content

Explain, in outline, the sequence of stages in mitosis (names of stages are not required).
Students to arrange individual stages of mitosis in the correct sequence.
Use diagrams/photographs to describe the separation of pairs of chromosomes during meiosis; the resulting cells are haploid and carry varied genetic information; they become gametes.
LIVING WORLD p236-7.
Cut and stick sheet showing stages of mitosis.
Carry out root tip squash, using video and microscope.

Homework/extension work.
Set test on mitosis and meiosis outcomes. Use a set of unlabelled diagrams out of sequence as the test sheets (names of stages are not required).
Nelson Modular Science I: p58.

Notes / Resources

Large diagrams or photographs showing root cells undergoing mitosis; Microscope slides of root squashes.
Cut and stick sheet showing stages of mitosis. 10/2/2, 10/2/2a examining dividing cells.
Root tip squash, using video and microscope, microscopes, slides, etc

Micrographs of meiosis and microscope slides of locust testis squash.

www.accessexcellence.com/AB/GG/comparison.html

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 3 - Variation I.

National Curriculum Statements.

4b that sexual reproduction is a source of genetic variation, while asexual reproduction produces clones
Specification Objectives

explain how sexual reproduction, involving fertilisation, leads to variation in the new generation

recall that individuals inherit some characteristics from their father through the sperm and some from their mother through the egg

Key words: sexual, variation, characteristic

Lesson Content
Emphasise the idea that fusion of haploid male and female gametes produces a diploid zygote with a mixture of genetic information from both parents. Use 'poppit' bead model chromosomes to demonstrate various possible combinations resulting from:
parents * gametes * offspring.

Discuss available examples of offspring not being identical to either parent but sharing some characteristics with each of them.

Measure variation of pupil characters. Discuss which are genetic and which are environmentally controlled. Also consider which are continuous/discontinuous.
Meiosis cut and stick sheet.

Homework/extension work.
Nelson Modular Science I: p48-50.

Notes / Resources
'Poppit' beads of different colours.
Pople p50-1 v. good ref.

Photographs of families; drawings of mammal families (cats, mice, etc.) showing different hair e.g. colour, length, degree of curl or straightness.
This topic requires sensitive handling and should not be based on the students' own families.
Meiosis cut and stick sheet. 10/2/3.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 4 Variation II.

National Curriculum Statements.

4a how variation arises from genetic causes, environmental causes and a combination of both

Specification Objectives

understand how some inherited characteristics can be modified by environmental conditions, e.g. the influence of the mother's diet or smoking on a baby's birth weight

Key words: inheritance, environment, variation

Lesson Content

Discuss the available data on the effects of the mother's diet or smoking habits on a baby's birth weight.
Drugs, diet and pregnancy worksheet. 10/2/4.

Homework/extension work.
Smoking and birth weight

Notes / Resources

Provide students with the necessary data to complete a homework task on this topic. The main search engines (particularly GOOGLE) provide many links to medical web sites on this subject. Teachers should be aware that such searches will throw up sites which deny links between smoking and cancer.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 5 The inheritance of sex.

National Curriculum Statements.

4d how sex is determined in humans
Specification

explain how the sex of an individual depends upon X and Y chromosomes and is determined at fertilisation

Key words: chromosome, fertilisation

Lesson content

Refer to full human karyograms similar to lesson 1 to establish the presence of XX chromosomes in female body cells and of XY in male body cells. Lead on to the appreciation that every ovum contains X, a sperm contains X or Y. Use cut out X and Ychromosomes to demonstrate that the sex of an individual is decided by whether the ovum is fertilised by an X or a Y sperm.
Worksheet sex of a baby for FT.

Homework/extension work.
Nelson Modular Science I: p51-2.

Notes/resources

Cardboard cut-out X and Y 'chromosomes'. 10/2/5.
Worksheet sex of a baby for FT.

www.bioweb.uncc.edu/biol1110/karyotyp.htm

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 6 Hormones.

National Curriculum Statements.

3e the hormonal control of plant growth and development, including commercial applications
Specification Objectives
describe the functions of the sex hormone testosterone in promoting secondary sexual characteristics in men

describe the functions of the sex hormone oestrogen in promoting secondary sexual characteristics in women

recall that oestrogen causes the lining of the uterus to thicken during the early part of the menstrual cycle

recall that progesterone maintains the lining of the uterus during the middle part of the menstrual cycle and during pregnancy

recall that manufactured sex hormones can be used to treat infertility in women

Key words: hormone, testosterone, oestrogen, progesterone, menstrual cycle, infertility

Lesson Content

Get pupils to list the changes that occur to males and females during puberty.
Define hormones as chemicals which bring about gradual changes in the body. Explain that each hormone is transported, from its site of production to its target organ, in the blood (refer to Module 1). Discuss the respective effects of testosterone (from the testes) and oestrogen (from the ovary) on the production of sperm cells and ova and on secondary sexual characteristics including deepening voice, broadening shoulders, body hair and development of mammary glands, establishment of menstrual cycle, broadening hips.

Explain the effects of changing levels of oestrogen and progesterone during a menstrual cycle and after conception.

Students write a report of the roles of oestrogen and progesterone, including diagrams and graphs. Explain briefly that oestrogen and progesterone can be used to regulate the menstrual cycle and therefore promote regular ovulation to increase the chance of conception; hormones from the pituitary gland which stimulate the ovary's production of oestrogen and progesterone can also be used to treat infertile women.
Video 123 hormones.

Homework/extension work.
Nelson Modular Science I: p45-7.

Notes / Resources
Series of diagrams showing growth from baby * child * adolescent * adult for males and females as visual stimulus for discussion (integrate this work with material covered in PSE lessons).
Students plot graphs from given data comparing age to height showing the growth spurt.
Diagrams and graphs showing the sequence of events in the ovary and in the uterus lining during normal menstrual cycles and when pregnant, and levels of oestrogen and progesterone in the blood stream coinciding with these events.
Diagram showing location of pituitary gland. 10/2/6. Resource packs on sex hormones.
Video 123 hormones. 10/2/6a hormonal levels and the cycle.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 7 - The double helix

National Curriculum Statements.

4e the mechanism of monohybrid inheritance where there are dominant and recessive alleles

Specification Objectives
understand that genes are parts of chromosomes which are found within the nucleus

understand that the unit of inheritance is the gene which is a section of a long chain (DNA)
molecule; describe a DNA molecule as two strands coiled to form a double helix, the strands linked by a series of paired bases (adenine with thymine and cytosine with guanine)

Key words: nucleus, chromosome, inheritance, adenine, thymine, cytosine, guanine

Lesson Content
Define a gene as a unit of inherited information. Students observe slides/photographs showing chromosomes in cell nuclei. Use 'poppit' beads to represent 'a string of genes' on a chromosome.
LIVING WORLD p234-5.

Use DNA models to explain the pairing of bases and the double helix.

Encourage the understanding that when each chromosome divides, the two strands of DNA separate and each strand replicates to restore the double helix structure.
LIVING WORLD 226-9.

Worksheet on structure of DNA. 10/2/7.
Video 63 reproduction and genetics.

Homework/extension work.
Nelson Modular Science I: p56-7.

Notes / Resources
Poppit beads.

DNA models.
Background information will be available from Edexcel in the Ideas and Evidence Support booklet publication code: UG009872.
Worksheet on structure of DNA. 10/2/7.
Video 63 reproduction and genetics.
What is DNA W/S 10/2/7a.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 8 - Looking at human DNA.

National Curriculum Statements.

4e the mechanism of monohybrid inheritance where there are dominant and recessive alleles
Specification Objectives
understand that genes are parts of chromosomes which are found within the nucleus

Key words: gene, chromosome, nucleus, double helix

Lesson Content
Isolate DNA from pupils cheek cells. Use same method as onions except there is no need to grind the tissue.

Notes / Resources

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 9 - ideas and evidence

Lesson content
Ideas and evidence lesson.
Read through sheet.
Extended speaking exercise.
Pupils could discuss in groups and then report back to the rest of the class.
Answer Q's in handout.
Summarise points that pupils could be assessed on.

Homework/extension work.
Notes/resources
Ideas and evidence handout on DNA. 10/2/9.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 10 - Monohybrid inheritance

National Curriculum Statements.

4e the mechanism of monohybrid inheritance where there are dominant and recessive alleles
4f about mechanisms by which some diseases are inherited
Specification Objectives

explain how alternative forms of a gene (alleles) cause variation in a characteristic, to include eye colour

recall that some alleles cause diseases which can be inherited

understand the terms dominant and recessive

describe the mechanism of monohybrid inheritance using genetic diagrams
understand the terms homozygous, heterozygous, genotype and phenotype

predict ratios of genotypes and phenotypes in a given monohybrid cross

Key words: gene, allele, disease, dominant, recessive, homozygous, heterozygous, genotype, phenotype

Lesson Content

Discuss the existence of different forms (alleles) of a gene which controls a particular characteristic, e.g. different eye colour alleles result in brown or blue eyes. Review ideas on different alleles for eye colour. Explain that an individual carries two of each gene in the nucleus of each diploid body cell. Define the terms 'dominant' and 'recessive'.

Students handle data on a number of crosses to construct genetic diagrams and show ratios of phenotypes and genotypes.

Define 'genotype' and distinguish between 'homozygous' and 'heterozygous'; define 'phenotype'.

Use genetic diagrams to show the outcomes from possible crosses between homozygous brown-eyed/heterozygous brown-eyed/blue-eyed phenotypes. Discuss the ratios which emerge.

LIVING WORLD p230-3
SCIENCE TO GCSE 50-1, 54-5.

Homework/extension work.
Nelson Modular Science I: p62-3.

Notes / Resources
Students need to use this skill to explain the inheritance of sickle cell anaemia and cystic fibrosis in module 8.

Teachers may wish to teach this topic using a Punnet square.

Differentiation here is a matter of using an understanding of the technical terms to predict phenotypic ratios.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 11 - Mutation

National Curriculum Statements.

4c that mutation is a source of genetic variation and has a number of causes
Specification Objectives

recall that a mutation is a change in the chemical structure of a gene

recall that mutations can be caused by ionising radiation, including ultraviolet light, X-rays and gamma rays, and by some substances in tobacco

Key words: mutation, radiation, tobacco

Lesson Content

Review the concept of a gene as a unit of genetic information controlling a particular characteristic, and explain that a mutation is a change in a gene. The changed genetic information may lead to variation.
Explain that mutations occur naturally; many are harmful, some have no obvious effect, a few are beneficial. A link is possible with sickle cell anaemia in module 8.

Discuss factors which increase the incidence of mutation to include: radiation from nuclear reactions, ultraviolet radiation, X-rays and chemicals such as those in tobacco smoke, particularly in the tar component.

At this point the cloning of cells can be revised in terms of cancer cell and bacterial cells with antibiotic resistance.
Recap monohybrid inheritance using sickle cell/ CF.

Extension work/homework.

Students research data on harmful effects of: Chernobyl; too much sunbathing linked to skin cancer; or smoking linked to lung cancer.

Notes / Resources

Reference material or list of internet sites, for example:

www.chernobyl.com/;
http://www.skincancer.org/;
http://www.imperialcancer.co.uk/

A good general study site for information and links is:
www.studyweb.com/search.htm
and do a search on skin cancer/smoking and health etc. for information and links to useful sites.

Education for citizenship.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 12 - Genetic modification

National Curriculum Statements.
4b that sexual reproduction is a source of genetic variation, while asexual reproduction produces clones
Specification Objectives

describe how the transfer of a required gene from a donor to a recipient, including the use of enzymes, can produce genetically modified organisms

understand that crop plants can be genetically modified, and the reasons for doing so

describe the potential benefits and ethical dilemmas posed by advances in genetic
modification

Key words: donor, recipient, genetically modified organism

Lesson Content
Use available resources to explain the sequence of events involved in genetically altering bacteria, ie isolation of donor gene and its incorporation into a plasmid vector using restriction enzymes; incorporation of the plasmid into bacteria and cloning them to produce human insulin.
Discuss the production of genetically modified plants to improve the production
of food including introducing resistance to pests, e.g. Pyrethrum gene in Soya, or to herbicides, e.g. herbicide resistance in oil seed rape, extending shelf life, e.g. in tomatoes for processing.
A guided discussion can lead to a homework task involving free prose or poster and an appreciation of both sides of a case.
LIVING WORLD p242-3, 254-7.
Video 123 biotechnology in plant breeding.
Video 126 genetic engineering.
Genetic engineering worksheet.
Pople p54-55.
Homework/extension work.
Nelson Modular Science I: p65-67.

Notes / Resources
Links with higher material in Biotechnology Module 14.
The following web sites have some useful information about genetically modified crops:
http://www.biotechbasics.com/
http://www.frontlineonline.com/fl1603/16030920.htm
Useful booklet: GM Crops and the Environment Food and Drink Federation
www.foodfuture.org.uk
National Centre for Biotechnology's website www.ncbe.reading.ac.uk/ under Human Genetics section has information and links relating to ethics, Human Genome Project and other related topics.
In February 1997, scientists at the Roslin Institute in Scotland announced a major breakthrough: Dolly the sheep. Refer to the Roslin website www.ri.bbsrc.ac.uk/
ICT opportunity: pupils could research that crops can be genetically modified and explain how this could be useful.
Education for citizenship.
Spiritual, moral, ethical, social and cultural issues.
Video 123 biotechnology in plant breeding.
Video 126 genetic engineering.
Genetic engineering worksheet. 10/2/12.
Pople p54-55.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 13 Human genome project.

National Curriculum Statements.

how variation arises from genetic causes, environmental causes and a combination of both
Specification

describe some of the implications of the outcome of the Human Genome Project

Key words: human genome project

Lesson Content

Use the ideas and evidence pamphlet as the basis for this lesson.
Refer to Nelson Modular Science I: p61.

· Review:
- role of base codes on DNA molecules in the control of human characteristics.
- some alleles cause disease and may be passed on from parents to offspring.

· Outline the work of the Human Genome Project. To include:
- Sanger invented the base sequencing technique in 1977.
- project initiated in 1986 in USA and UK.
- first human genome map of 30 000 genes in 1996.
- completed genome (based on anonymous DNA donors) to be published by 2003

· Outline:
- searching for single genes.
- the more difficult task of detecting recessive alleles.
- the most difficult task of detecting features controlled by multiple genes.
Consider the issues surrounding the identification of an individual's alleles
- tests could be made available to map the alleles of individual people.
- can compare the DNA patterns of genetic "disease" groups with healthy groups.
- discuss the effects of this information on individuals in terms of ethics, legal, and social implications.
Consider:
- "Who owns the information?".
- people may be highlighted who have a gene combination, very likely to develop e.g. heart disease - "Should the life insurance companies have access to the information? Should employers have access to the information?".
LIVING WORLD p240-1.
SCIENCE TO GCSE p52-3.

Notes / Resources

Ideas and evidence sheets.
Obtain the series published by The Wellcome Trust, including Beyond the Genome
- produce a poster which shows a complete atlas of human genes along the chromosomes (when data becomes available during the lifetime of this specification).
Search the internet
- Human Genome Project data is to be published in the internet.
- analyse the media responses.
- summarise the main issues from published articles.
- capture the moment as headlines appear for maximum impact.
Websites:
- www.hgmp.mrc.ac.uk
UK Human Genome Project
- www.hugo-international.org
International Human Genome Project
- www.nhgri.nih.gov
UK HGP Research institute
- www.ncgr.org/gpi/Index.html
Genetics and Public Issues Archives

List debating issues or question via worksheets:
- Which chromosomes control a characteristic?
- Which genes control a characteristic?
- Which genes are responsible for a disease?
- Will it be possible to replace these genes?
- How may the information help potential parents?
- How may the information be used by a genetic counsellor?
- How can the information help the targeting of specific drugs?
- Why have drugs companies funded the Human Genome Project?
ICT opportunity: internet research
Spiritual, moral, ethical, social and cultural issues.
Education for citizenship - describe the human genome project.
W/S 10/2/13 what is a genome?

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 14 - Adaptation to environment

National Curriculum Statements.

4j how variation and selection may lead to evolution or extinction
Specification Objectives

understand how adaptations such as:
- hair colour, hair length, size of ears in mammals
- gills, streamlined shape, mucus-covered scales in fish
- extensive roots, reduced leaves with thick cuticles in cacti
allow survival in particular environmental conditions

Key words: adaptation, environmental,

Lesson Content

Use the available resources to help a discussion of how features such as shape, colouration, body covering, body temperature and possession of gills or lungs helps various mammals, fish and drought tolerant plants to survive in their environment.

LIVING WORLD p250-3.

Extension / homework.
Design an animal that could live on Jupiter. Make one!

ICT opportunity: peppered moths/frogs/beetles programs.

Video private life of plants: dispersal. Pupils watch and list adaptations.

Homework/extension work.
Nelson Modular Science I: p69-70.

Notes / Resources

Specimens (living or preserved); photographs/ drawings of mammals; fish and cacti.

Cacti can be cultured in the school glasshouse or laboratory. Other drought tolerant plants like broom can be grown in the school garden. Reference to marram grass on sand dunes may be relevant if students are familiar with such sites. Refer
www.microscopy-uk.org.uk/schools/images/marram.html

Preserved specimens should be in formafree preservative.
Cacti should be of the spiny type rather than the 'irritating hair' type.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 15 - Populations

National Curriculum Statements.

5a how the distribution and relative abundance of organisms in habitats can be explained using ideas of interdependence, adaptation, competition and predation
5b how the impact of humans on the environment depends on social and economic factors such as population size, industrial processes and levels of consumption and waste
Specification Objectives

describe how competition between individuals of the same species controls population size

describe how the populations of predator and prey are dependent on each other

recall that increasing population size leads to increased pollution

Key words: competition, population, predator, prey, pollution

Lesson Content

Discuss how increasing numbers of a species causes pressure relating to food supply, overcrowding, disease and aggression.

Explain the link between availability of food supply (prey) and changing predator levels.
Students use available data to trace the fluctuations in populations of both predator and prey over a number of years, including plotting a graph (one example is the lynx and snowshoe hare).

Briefly outline the impact on the environment of the increased need for food, housing and industrial activity as the human population increases and societies become more advanced.

SCIENCE TO GCSE p58-9.

Demonstrate creatures to pupils. This is the year 10 biology investigation counting 20% of final marks. Suggest that low ability groups look just at grass populations, middle ability look at the effects of changing plant parameters on rabbit populations, and high ability groups look at the effects on foxes, rabbits and grass. This should take about a lesson to plan, a lesson to carry out, and two lessons to write up. Do this either now if you have time, or after May half term. Good luck.

Homework/extension work.
Nelson Modular Science I: p71.

Notes / Resources

ICT opportunity: computer simulation relating to populations of linked pairs of organisms (predator and prey) or try:

www.sciencesschool.com

Creatures worksheet.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 16 - Evolution

National Curriculum Statements.

4i that the fossil record is evidence for evolution
4j how variation and selection may lead to evolution or extinction
Specification Objectives

describe how new species may evolve from variants which are better adapted to their environment
understand that fossils provide evidence for evolution
explain how natural selection can lead to evolution or extinction of species
explain the principles of natural selection

Key words: evolution, fossil, natural selection, adaptation

Lesson Content
Guide a class discussion about variation between individuals of characteristics which may affect survival, e.g. acuteness of senses and speed of movement, both of which affect the chances of catching prey and of avoiding danger.
Review ideas of variation and the concept that those best suited to the environment will breed and pass on their advantageous genes, i.e. Natural Selection.
LIVING WORLD p246-7.
Discuss the relevant features of 'clean' and 'sooty' habitats before and after the industrial revolution.
Develop the simple understanding of what has happened to the proportions of light and dark varieties of peppered moth over the years, to include:
- the dark form arose as a mutation.
- birds prey on peppered moths.
- light form well camouflaged in 'clean' habitat.
- industrial air pollution killed lichens and darkened tree trunks and walls.
- dark form better camouflaged in 'sooty' habitat.
- Clean Air Act reduced industrial pollution so that proportions of light and dark varieties again changed.
SCIENCE TO GCSE p56-7.
Discuss evolution of the horse.
Video 45 evolution, 65 Darwin and evolution.
Homework/extension work.
Nelson Modular Science I: p72-3

Notes / Resources
A range of fossils.
Video 45 evolution, 65 Darwin and evolution.
A good general site is www.britannica.com where students can do a search on 'peppered moths' which provides a 'species' description and links to related articles.
Other sites include:
http://www.heg-school.awl.com/bc/companion/dobiol/moths.html;
www.utm.edu/~rirwin/moth.htm;
http://www.wm.edu/biology/melanism.pdf
although the content of the last website may be aimed at a higher level than GCSE and may need to be reviewed by the teacher.
Spiritual, moral, ethical, social and cultural issues - fossils for evolution.
W/S 10/2/16 the evolution of the horse.

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution

Module 2 - Lesson 17 - Artificial selection

National Curriculum Statements.

4b that sexual reproduction is a source of genetic variation, while asexual reproduction produces clones
Specification Objectives
explain how selective breeding (artificial selection) can be used, for example,
- in cattle to improve the quality and quantity of milk

- to increase the number of offspring in sheep

- to increase yield from dwarf wheat

Key words: selective breeding, artificial selection

Lesson Content

Explain that selective breeding is not a new idea; in early civilisations farmers selected seed for next year's sowing and decided which animals to kill for food and which to use for breeding. Explain development of modern varieties of cattle (e.g. Holstein / Friesian for milk quantity, Jersey for milk fat content and Angus / Hereford for beef).

Discuss the desirable features that were selected in the cattle.

Explain that artificial insemination allows sperm from a prize bull to be used with many cows, without the cost of individual farmers keeping a bull.

Discuss selective breeding in sheep to increase the number of ewes which produce twins. This provides more animals for market and therefore greater profit.

Discuss the introduction of dwarf genes to wheat to reduce the amount of growth that goes into straw leading to an increase in yield.

Video good breeding.

Homework/extension work.
Nelson Modular Science I: p74.

Notes / Resources

Video good breeding.

Dairy Daughters or any other artificial insemination catalogue
www.dairydaughters.co.uk contains interesting data on prices for breeding bulls including production type and yield and also provides links to other sites with useful information on artificial insemination and selective breeding.

Refer to the following websites for useful information and links:
Plant Breeding International Cambridge website
www.pbi-camb.co.uk;
Daily Press, Genes for a Revolution with links to articles: www.academicpress.com/inscight/07141999/graphb.htm
Spiritual, moral, ethical, social and cultural issues

Overview: Chromosomes/variation Genes/variation Selection/evolution Pollution
Module 2 - Lesson 18 - Pollution

National Curriculum Statements.
5b how the impact of humans on the environment depends on social and economic factors such as population size, industrial processes and levels of consumption and waste
5c about the importance of sustainable development
Specification Objectives
interpret data on environmental change
describe how human activity can affect the environment, especially changes in population
size, and in economic and industrial conditions, given suitable information
recall that burning fossil fuels releases harmful wastes into the air, especially smoke and acidic gases
recall that acidic gases combine with water vapour to form acid rain which damages plants and animals
recall that some harmful substances occur in vehicle exhaust gases, including carbon dioxide, carbon monoxide, nitrogen oxides
describe how air pollution by vehicles can be reduced

Key words: pollution, carbon dioxide, fossil fuels

Lesson Content
Define pollution as the contamination of the environment by waste substances and identify the burning of fossil fuels (especially for energy production in industrialised countries) as a major source of air pollution.
Discuss the effects of sulphur dioxide to include:
- damage to human lungs when sulphur dioxide in inhaled air dissolves in the moist lining of the alveoli.
- damage to plant leaves, e.g. in forests, by 'acid rain'.
- disruption of plant and animal populations in lakes polluted by 'acid rain'.
Introduce the idea of increased vehicle use and the problem of increased air pollution leading to health problems such as damaged lungs.
Guide a discussion of possible solutions to the problem of pollution by vehicle exhaust gases to include: the use of vehicles powered by alternative fuel, increased provision of public transport, traffic-free zones, reduced speed limits, increasing the price of fuel and of road tax and of parking fees.
SCIENCE TO GCSE p60-1.
Video 119 Emission Impossible, video 37 Los Angeles Traffic Pollution
Extension / homework. How air pollution by vehicles can be reduced. Nelson Modular Science I: p75-6.

Notes / Resources
Related Sc1 practical assessment activities could include:
i) Groups of students set up cress seeds to germinate, moistened by water or by a range of concentrations of dilute sulphuric acid, or leave germinated seeds in a sealed container with sodium hypochlorite solution. (observe results during next lesson).
ii) Students carry out a survey (by field work or by data analysis) of the distribution of plants (lichens or others) in relation to the degree of air pollution.
Teachers may wish to consider the investigation outlined in the SAPS 2001 Spring Newsletter
www-saps.plantsci.cam.ac.uk
Spring 2001 Newsletter - Lemma minor investigations
ICT opportunity: internet research on how acidic gases combine with water vapour to form acid rain which damages plants and animals.
Video 119 Emission Impossible, video 37 Los Angeles Traffic Pollution
Safety Precautions See Hazcard: sulphuric acid.

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