Biology
Unit 6
Genetics and Meiosis
Study Guide
Name ______________________________________
-Always bear in mind that your own resolution to
succeed is more important than any other.
-Abraham Lincoln
Section 11.1 Introduction to Genetics (pages 262 – 266)
Objectives.
1. Describe how Mendel studied inheritance in peas.
2. Summarize Mendel’s conclusion about inheritance.
3. Explain the principle of dominance.
4. Describe what happens during segregation.
1. What is genetics and why has it become so important in Biology?
2. Who was Mendel? Why did he end up working with Peas?
3. What is fertilization? Why were Mendel’s pea plants called true breeding?
4. How was Mendel able to prevent the pea plants from self-pollinating?
5. What is a trait? What were some of the traits of the pea plants?
6. What is meant by the terms P (parental), F1 (first filial) and hybrids?
7. What are genes? What are the different forms of a gene called? Give some examples for the
Pea plants (page 265)
8. State the principle of dominance. Give two examples for the pea plants. (p. 265)
9. What is segregation? What happens to alleles during segregation? (p. 266)
10. Why did only about ¼ of Mendel’s F2 plants exhibit the recessive trait?
Section 11.2 Probability and Punnett Squares. (pages 267- 269)
Objectives.
1. Explain how geneticists use the principles of probability.
2. Describe how geneticists use Punnett squares.
1. What is probability? What is the general rule for the probability of an event happening
several times in a row? (Say getting heads 4 flips in a row!)
2. Chance was flipping coins. He flipped 5 heads in a row! What is the probability that the 6th
flip would be heads? (Support your answer!)
3. Tacks can be flipped as well. In this case there is a 40% chance that the tack will land with
the point up and a 60% chance that it lands with the point down (
) In this case what
are the odds of a tack landing point down four times in a row?
4. How are Punnett squares used? (page 268)
5. What is meant by the terms homozygous and heterozygous? Give an example using the
pea plants.
6. What is meant by the terms phenotype and genotype? Give examples on how some plants
can have the same phenotype and yet have different genotypes.
7. Geneticist Marge N. Error crosses a plant that is homozygous for shortness with a plant
that is heterozygous tall. Fill in the Punnett square below showing the possible
genotypes for their offspring.
11.3 Exploring Mendelian Genetics (p. 270-274)
Objectives.
1. Explain the principle of independent assortment.
2. Describe the inheritance patterns that exist aside from simple dominance.
3. Explain how Mendel’s principles apply to all organisms.
1. Explain what independent assortment means. (p. 270)
2. Summarize Mendel’s Principles.
3. What is meant by incomplete dominance? Give an example. (p. 272)
4. What is meant by codominance? Give an example.
5. What is meant by Multiple Alleles? Give an example.
6. What is meant by Polygenic traits? Give an example.
7. Why are fruit flies an ideal organism for genetic research? (p. 274)
8. Rabbit breeder Leapus O’Hare is studying coat color in Rabbits. He crosses a male
rabbit with genotype CC with a female rabbit having genotype CCch. O’Hare then crosses
a CCch male with a CCch female. In which of the two crosses are the offspring more likely
to show greater variation? Use Punnett squares to explain your answer.
11.4 Meiosis (p. 275 – 278)
Objectives.
1. Contrast the chromosome number of body cells and gametes.
2. Summarize the events of meiosis.
3. How is meiosis different from mitosis?
1. What is the main result of meiosis?
2. How many chromosomes does the adult fruit fly have? The gametes?
3. What is meant by homologous chromosomes? How many does a fruit fly have?
4. What is meant by the term diploid? What is the diploid number for a fruit fly?
5. What is meant by the term haploid? What is the haploid number for a fruit fly?
6. What is meiosis? (p. 275)
7. How is prophase of meiosis I different from mitosis? What is a tetrad? (p. 276)
8. What is crossing over? When does this occur?
9. How are the daughter cells different from the parents at the end of meiosis I?
10. What happens in meiosis II that causes the four daughter cells to have half (N) the normal
number of chromosomes of the original cell? (p. 277)
11. How does gamete formation differ between males and females?
12. In human cells 2N = 46. How many chromosomes would you expect to find in a sperm
cell? In an egg cell? In a white blood cell?
11.5 Linkage and Gene Maps. (pages 279 – 280)
Objectives
1. Identify the structures that actually assort independently.
2. Explain how gene maps are produced.
1. How does the principle of independent assortment apply to chromosomes?
2. What are gene maps and how are they produced?
3. How does crossing over make gene mapping possible?
4. If two genes are on the same chromosome but usually assort independently, what does
that tell you about how close together they are?