Download Genetics Study Guide

Genetics Study Guide
Part A: Answer the following questions on a separate sheet of paper.
1. Explain the process of RNA transcription.
2. How is RNA different from DNA?
3. What are the three types of RNA?
4. Explain the process of translation.
5. Transcribe this DNA sequence into mRNA. Use the chart on p. 149 to translate the sequence
into amino acids. TAC TCC GAT CTA TTC GCG CTT ATT GCA CAT
5. Describe meiosis. How is it similar to mitosis? How is it different?
6. What separates during meiosis I?
7. What separates during meiosis II?
8. What is cross-over? When does it happen? Why is it important?
9. How is sperm production different from egg production?
10. What is nondisjunction? When and how does it happen? What types of disorders can it
cause?
11. Define the following vocabulary words: codon, anticodon, haploid, diploid, dominant,
recessive, homozygous, heterozygous, homologous chromosomes, phenotype, genotype,
allele, karyotype, monosomy, trisomy.
12. What is a sex-linked trait? Who is more likely to inherit a sex-linked disorder? Why?
13. What are five environmental influences on phenotype? Give examples of how each affects
phenotype.
14. What determines the sex of a child?
15. What is polygenetic inheritance?
16. List several traits that have multiple alleles.
Part B: Determine the chromosome number for each of the following problems for an
organism that normally has 16 chromosomes in a heart cell.
1. What is the diploid number?
2. What is the haploid number?
3. How many chromosomes in an egg cell?
4. How many chromosomes in a brain cell?
5. How many chromosomes in a skin cell?
6. How many pairs of homologous chromosomes?
7. How many chromosomes in a cell produced by mitosis?
8. How many chromosomes in a cell produced by meiosis?
9. How many tetrads are there in prophase of meiosis I?
10. How many dyads are there in prophase of meiosis II?
Part C: Read each statement and decide whether they are true or false. If a statement is true,
write, “This statement is true”. If a statement is false, rewrite it so that it is true.
1. Being heterozygous is an example of phenotype.
2. Having brown eyes is an example of genotype.
3. If a person has one dominant allele and one recessive allele, they will have the dominant trait.
4. It is always possible to figure out genotype if you know a person’s phenotype.
5. It is always possible to figure out phenotype if you know a person’s genotype.
OVER
6. If a person is heterozygous for brown eyes, they cannot have a blue eyed child.
7. If a person is homozygous dominant, they can have a child who looks like the recessive trait.
8. The bonding area on a tRNA molecule is known as a codon.
9. Cells produced by meiosis are haploid.
10. Cells produced by mitosis are diploid.
Part D: For each of the following examples, work a Punnett Square and give the genotypic
and phenotypic ratios of each cross.
1. In cows, having no horns is dominant to having horns. Show a cross between a heterozygous
cow and a horned cow.
2. In beans, curly leaves are dominant to flat leaves. Show the cross Ll x Ll.
3. In humans, long eyelashes are dominant to short lashes. Show a cross between a
homozygous dominant person and a heterozygous person.
4. Hemophilia is a sex-linked bleeding disorder. Show a cross between a woman who carries the
disorder and a man who does not have it.
5. In peas, yellow is dominant to green, and wrinkly is dominant to round. Show a dihybrid cross
between two pea plant that are heterozygous for yellow wrinkly peas.
6. Color-blindness is a sex-linked disorder. Show a cross between a man who has it and a
woman who does not carry the gene.
7. Human nose width shows incomplete dominance. Show a cross between two people with
medium-width noses.
8. In cattle, the red and white hair alleles show codominance. Show a cross between a
heterozygous cow and a cow that is homozygous for the red allele.
9. In pea plants, green seeds are dominant over yellow seeds, and being tall is dominant over
being short. Show a dihybrid cross between two pea plants that are heterozygous for both
traits.