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Unit 4 Genetics Study Guide

IB Biology 11 Study Guide Unit 4: Meiosis & Inheritance
❏ I can identify patterns of inheritance given a pedigree chart (sex-linked
dominant/recessive, autosomal dominant, autosomal recessive)
❏ I can determine the probability an individual is a carrier of a recessive trait given a
pedigree chart
❏ I can identify sex and nondisjunction given a karyogram
❏ Given the blood type of the child’s parents, I can determine the possible genotypes of
the offspring
❏ Given a micrograph, I can determine the phase and correct order of the events that take
place during meiosis
❏ Given a Punnett square, I can determine the genotype and phenotype probabilities of
the cross
Answer the questions below and submit via google classroom for 20 points:
1. What is meiosis?
2. What causes genetic variety in the formation of gametes during meiosis?
3. During which phase of the first division of meiosis can non-disjunction take place and
what structure is affected by the non-disjunction?
4. Define a gene
5. What distinguishes an allele from a gene?
6. What is the set of alleles that an individual possesses?
7. In a cross between red haired cattle and white haired cattle the offspring produced are
always a color called roan (light red). If the roan cattle are interbred they produce white,
roan and red offspring. How many alleles are controlling this character?
8. What do all human males inherit from their mother?
9. When are the pairs of sister chromatids that are visible during meiosis formed?
10. Laboratory analysis of DNA from a 40 000 year old woolly mammoth used the
polymerase chain reaction (PCR). What role did the PCR have in the analysis?
11. What is the chromosome number in a human gamete with non-disjunction? (How many
12. If a man with blood group O and a woman with blood group AB have children, which
blood group(s) could the children have?
13. What causes the presence of three chromosomes 21 in Down syndrome?
14. What is the difference between dominant, recessive and codominant alleles?
15. What is the name given to a heritable factor which controls a specific characteristic?
16. In humans a V-shaped hair line is dominant to a straight hair line. A
woman with a V-shaped hair line and a man with a straight hair line have
children. The woman has a mother with a straight hair line. What is the
proportion of children who are likely to have a V-shaped hair line?
17. A small amount of a suspect’s DNA is obtained from a crime scene. What techniques
would be used to carry out DNA profiling?
18. Describe the relationship between genes, polypeptides and enzymes.
19. Define codominant allele, recessive allele, locus and sex linkage.
20. ABO blood groups are inherited from parents, but it is possible for a child to have a
different blood group from either parent. Outline how this can happen using a Punnett