Genetics Test review 2015

1. Name_______________________ Date_______
Class_______
1. List two facts about Sexual reproduction and two examples of organisms that undergo sexual
reproduction.
a. ______Produces genetically unique off spring__
b. _____ Involves 2 parents
c. Examples: ________Humans, Dogs, Frogs etc. ____________
2. List the things that determine a trait
a. ____One gene_____
b. ____Several genes______
c. _____Environment_____
3. Where is genetic information contained within a cell
a. _____Nucleus_______
4. Why do scientists use organisms like pea plant, fruit flies, and bacteria to study genetics?
______They reproduce quickly, they are simpler, they are inexpensive
5. Describe the differences between sexual reproduction & asexual reproduction. ___
Sexual Asexual
2 parents 1 parent
Genetically unique offspring Offspring are identical to parent (clones)
Complex organisms (humans) Simple organisms (Bacteria, Amoeba)
6. Describe the differences between Meiosis and Mitosis? ____ Mitosis – body cells, cell have 46
chromosomes, Meiosis- Gametes (sperm/egg), half # of chromosomes 23
7. Determine whether each event is sexual reproduction or sexual reproduction:
a. An orange cat is mated with a white cat, in hope of producing tortoiseshell cat.
___________Sexual_______________

2. b. A cutting is taken from a red-flowered geranium and placed in water to develop roots.
Once roots have grown, the new plant is placed in soil and grows to produce another red-
flowered geranium. )_______Asexual_________
c. A male fish releases sperm cells into the water. One of the sperm cells unites with an egg
from a female fish to form a new cell that grows into a new fish.
_____________Sexual________
8. What is the only way the offspring of asexual reproduction would not be identical to the parent.
______a change in the dna by a mutation__________________________
9. Which type of organisms can reproduce sexually? Asexually? ___Sexually- Humans, cats, horses,
dogs etc__________Asexually-plants, Amoeba , bacteria, yeast, hydra
_______________________________________________________________________________
____________________________
10. When writing the genotype which letter represents the dominant allele and which represents the
recessive allele? A & a
11. Using A & a, write the:
a. Homozygous dominant genotype: __________AA______________
b. Heterozygous genotype: _____________Aa__________
c. Homozygous recessive genotype: ________aa________________
12. The Punnett Square is used to determine : ___ The probability of traits in an offspring from two
parents.
Complete the following Punnett Squares:
13. Gg x gg
a. What is the ratio of dominant to recessive for this trait?
14. Both parents are carriers for a genetic trait,
G = green leaves

3. g = yellow leaves
Gg x Gg
a. What does it mean to be a carrier? ____Carry a recessive allele (little letter)
____________________
_________________________________________________________
b. What is the ratio of dominant to recessive for this trait?
G g
GG Gg
Gg gg
75% dom – 25% recessive
15. Gg x GG
a. What is the ratio of dominant to recessive for this trait?
16. Describe the amount of genetic material the offspring gains from each parent in
a. Sexual reproduction: _________1/2 ____ (23 from Mom/23 from Dad in humans)
b. Asexual reproduction: The same as the original cell.
17. Why do humans have two sets of chromosomes? One of each chromosome from Mom and one
from Dad.
18. How many chromsomes come from each human parent ? 23
19. How many chromosomes are in the body cells of a human? 46

4. 20. How is it possible for every human, including brothers and sisters to be genetically unique?
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
21. Explain how identical twins are an exception?
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
22. Describe the role genes and environmental factors in determining characteristics?
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
23. Determine each individual’s genotype. Hint: You may have to complete a Punnett Square. Let the
letter “D” represent the alleles
24. Determine each individual’s genotype. Hint: each individual has one allele what is the other?
25. Determine each individual’s genotype. Hint you may have to complete a Punnett Square. Let
B = Black

5. b = chestnut

6. b = chestnut