DO NOW (Just write answers) • What is incomplete dominance • Define recessive • Where does the variation in gametes arise from in meiosis • What is the purpose of meiosis • What is mitosis • What is an allele • What does homozygous and heterozygous mean
THIS TERM Week 1: GENETICS Week 2: GENETICS Week 3: GENETICS Week 4: ANIMALS Week 5: EXAM WEEK Week 6: ANIMALS Week 7:ANIMALS Week 8: PLANTS Week 9: FIELD TRIP Week 10: PLANTS
THIS TERM • HOMEWORK – BIOZONE AND EXAM QUESTIONS (past test results) • IN CLASS WORK ETHIC • HELP: WED LUNCHTIMES
REVIEW – USE WHITE BOARDS • Write the combinations for gametes for the following crosses • HhBB x HHBb • PpHh x ppHh • RrFf x rrFF
TO DO ON BOARDS IF FINISHED GRAB WORKSHEET FROM FRONT • In summer squash, white fruit colour (W) is dominant over yellow fruit colour (w) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d) • If a heterozygous white coloured sphere shaped squash was crossed with a yellow coloured homozygous disk shaped squash what would the phenotype ratio of their offspring be?
EXAM QUESTION 2004 • In horses, black coat colour is influenced by the dominant allele (B) and chestnut coat colour by the recessive allele ( b). Trotting gait is due to dominant gene (T), pacing gait to the recessive allele (t). • A horse trainer wanted to find the genotype of a black trotter she bought.. • Give the genotype and phenotype of the horse she would use to find out the genotype of a black trotter. Explain your answer • Use a punnett square to work out the phenotypic ratio of all possible offspring when a black male heterozygous for both traits is mated with a female heterozygous for both traits. • Explain why, when breeding chestnuts together she would not get any black foals, but when breeding black horse she could get chestnut foals
SEX LINKAGE • This occurs when genes are located on the sex chromosomes either the X or the Y chromosome (note: autosomes are the other chromosomes) • Example: Colour blindness • Sex linked gene located on the X chromosome • N = normal n = colour blind • XN = normal vision Xn = colourblind • Y = male
PROBLEM: • Can a woman with normal vision whose father was colour blind have colour blind children if she marries a normal visioned male? • Genotypes? • Do a cross? • Continue with extra questions