Download Genetics Test Review Key

Name: ___________________________
Period: ________
ACA Meiosis, Genetics & Heredity Test Review
Date: ________
1. How are an organism’s complex traits determined? DNA contains codes for proteins which are
necessary for growth an functioning in an organism.
2. Why is the sequence of the nitrogen bases in DNA so important for an organism? The sequence
provides the instructions for the traits of an organism.
3. Humans have different cells that perform different functions (i.e. cheek cells, blood cells etc).
Would each of these body cells (somatic) all contain the same full set of DNA? Yes
Answer questions 4-8 using the Karyotype to the right.
4. What is a Karyotype used for? Detect/Identify
chromosomal abnormalities.
5. Is the Karyotype to the right of a male or female?
Female (XX)
6. Is there a chromosomal defect? No.
7. Is there an extra or missing chromosome? No.
8. Can the karyotype determine if a mutation in a gene has
occurred? No. Karyotypes only detect chromosomal
abnormalities and gender.
9. What type of inheritance is crossing a white bull with a red cow resulting in a roan (red and
white) offspring? Codominance.
10. In snapdragons, the combined expression of both alleles for flower color produces a new
phenotype that is pink. This is illustrated below. What is this called? Incomplete Dominance
11. What process that produces gametes? Meiosis
12. Define:
Haploid: having one set of chromosomes (1n) ex. Sperm, eggs
Diploid: having two sets of chromosomes (2n)
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13. What is the process below and what does it increase? Crossing over; genetic variation
14. When an organism has two alleles of a particular gene that are different: heterozygous
15. When an organism has two alleles of a particular gene that are the same: homozygous
16. Fill in the chart below with the correct number of chromosome for each type of cell division
Organism
Amoeba
Cat
Goat
Human
# of chromosomes in
Diploid cells
50
38
60
46
After Meiosis
(Gametes) (1n)
25
19
30
23
After Mitosis (Somatic
Cells) (2n)
50
38
60
46
17. Define chromosome segregation: the process in eukaryotes by which two sister chromatids, or
paired homologous chromosomes, separate from each other and migrate to opposite poles of
the nucleus. This segregation process occurs during both mitosis and meiosis.
18. What is an allele considered to be if that allele is expressed and the other is not? Dominant
19. Use the genetic key chart to write in the correct genotype
Pea Plants
Cocker Spaniels
T=tall
Y-yellow
t= short
y-green
B=black coat color
b=brown coat color
Guinea Pigs
Tomato plants
B=black fur
F=short fur
b=brown fur
f=long fur
H=hairy stems
h=hairless stems
Organism
Homozygous tall, heterozygous yellow, pea plant
Heterozygous black cocker spaniel
Brown cocker spaniel
Guinea pig that is heterozygous for both traits
Heterozygous hairy tomato plants
Heterozygous black, long fur Guinea pig
Possible genotypes
TTYy
Bb
bb
BbFf
Hh
Bbff
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20. What is the expected outcome of two tomato plants that are heterozygous for hairy stems?
25% hairless: 75% hairy
21. The segregation that occurs during meiosis results in: A reduction in the number of
chromosomes per cell.
22. If pea plants with the genotype TTYy is crossed with a pea plant with genotype Ttyy, what
percentage of offspring will be expected to have TtYy? 25%
23. What are the components of DNA that are referred to as the genetic code? Nitrogen bases
24. If you cross a pink snapdragon with a white snapdragon. What percentage would be red?
(rr) red, (ww) white, (rw) pink
0%
25. What are all the possible blood types for the offspring produced by a type “O” mother and an
“AB” father?
50% A : 50% B
26. A woman that is heterozygous for normal blood clotting is crossed with a man that has normal
blood clotting. H = normal blood clotting
h=hemophilia
a. What are the chances that their offspring will have hemophilia? (Draw a Punnet Square)
25%
b. (See previous question) If hemophilia is sex-linked to males, what are the chances that their
male offspring will have it? 50%
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27. Why is sexual reproduction important? Meiosis ensures that there is genetic variation within the
offspring that results from two parents.
In pea plants, tall plant are dominant to short pea plants. The Punnett square below shows the results
of cross between 2 tall pea plants.
28. Based on the Punnett Square, approximately how many individuals
are expected to be short out of 600? 150
29. Based on the same Punnett square, approximately how many
individuals are expected to be tall out of 220? 165
30. Name each of the processes below as Mitosis or Meiosis
Mitosis
Meiosis
31. Predict the genotype of individual #14
f=Attached earlobes
F= Free earlobes
ff - attached
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