Inheritance and genetic crossesIB MYP Biology: Flashcards
What these 14 flashcards ask
- What is an allele?
- What does dominant mean?
- What does recessive mean?
- What is the difference between genotype and phenotype?
- What do homozygous and heterozygous mean?
- What ratio does Tt × Tt give?
- What ratio does Tt × tt give?
- Probability of tt from Tt × Tt?
- Which sex chromosomes do females and males have?
- What is the chance that a baby is a boy?
- What is a carrier?
- Is cystic fibrosis dominant or recessive?
- Is Huntington's disease dominant or recessive?
- What is sickle cell disease?
Exam questions on Inheritance and genetic crosses
- A student in Nairobi studies inheritance in pea plants. The gene for height has two alleles: the allele for tall stems (T) is dominant and the allele for short stems (t) is recessive.Define the terms allele and dominant.2 marks
- A breeder in Lisbon keeps guinea pigs. Black fur is controlled by a dominant allele (B) and white fur by a recessive allele (b). She has two heterozygous black guinea pigs and one white guinea pig.The breeder crosses a heterozygous black guinea pig with the white one. State the expected ratio of black to white offspring and the genotype of the black offspring.2 marks
- Cystic fibrosis is an inherited disorder caused by a recessive allele (f). A healthy couple, Amara and Kwame, have a first child who has cystic fibrosis. Both parents carry one copy of the allele.Explain how two healthy parents can have a child with cystic fibrosis.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).