Name: _________________________________ Hour: 1 2 3 4 5 6 7 Date: __________________
Genetics and Heredity Study Guide
Directions:
Please answer all of the questions as completely as possible. In all cases choose the most
scientifically correct response for all of the questions.
1. What is Heredity?
2. What is Genetics?
Define the following terms:
3. Gene:
4. Trait:
5. Allele:
6. Phenotype:
7. Genotype:
8. Incomplete Dominance:
9. Purebred:
10. Hybrid:
11. Homozygous:
12. Heterozygous:
13. Dominant:
14. Recessive:
15. Explain in 3-5 sentences, at least 3 reasons why the study of heredity and genetics is important
to society.
Please Write Genotype Symbols for the following the first one is done for you as an example:
16. Black Fur is dominant over white fur for puppies.
What is the genotype of a purebred dominant fur puppy?
_BB_
17. Blue Eyes are recessive to brown eyes for humans.
What is the genotype for a purebred recessive child?
____
18. Red petals are dominant to white petals for roses.
What is the genotype for a hybrid red rose?
____
19. Tall pea plants are dominant to short pea plants.
What is the genotype for a short pea plant?
____
20. Round pea seeds are dominant to wrinkled pea seeds.
What is the genotype for a hybrid round pea seed?
____
21. Green skin is dominant to yellow skin for frogs.
What is the genotype for a purebred dominant frog?
____
22. Long abdomens are dominant over short abdomens for wasps.
What is the genotype for a purebred recessive wasp?
____
23. Wide tails are dominant over narrow tails for trout.
What is the genotype for a heterozygous tailed trout?
____
24. Sneeches with stars on their bellies are dominant over
Sneeches without stars on their bellies. What are the 2
possible genotypes for a Sneech with a star on its belly?
____
____
25. Long manes for horses are dominant over short manes
for horses. What is the genotype for a horse with a short
mane?
____
26. Explain the difference between heterozygous and homozygous:
27. Explain the difference between purebred and hybrid:
28. Brown fur is dominant over white fur for mice. If we crossed a heterozygous brown fur mouse
with a homozygous recessive white fur mouse, the Punnett square would be as follows:
B
b
Bb
Bb
b
b
Bb
bb
What would the genotype ratio be? Please write the ratio in the format of BB:Bb:bb
____:____:____
What percentage of the offspring would have brown fur?
What percentage of the offspring would have white fur?
What percentage of the offspring would be heterozygous?
What percentage of the offspring would be homozygous?
29. Yellow eyes are dominant over blue eyes for cats. If we crossed a homozygous dominant yellow
eyed cat with a homozygous recessive blue eyed cat, the Punnett square would be as follows:
Y
y
y
Y
Yy
Yy
Yy
Yy
What would the genotype ratio be? Please write in the format of YY:Yy:yy
____:____:____
What percentage of offspring would have yellow eyes?
What percentage of offspring would have blue eyes?
What percentage of offspring would be heterozygous?
What percentage of offspring would be homozygous?
30. If SpongeBob Squarepants is heterozygous for his yellow color (Yy) and he marries SpongeSuzie
Roundpants who is homozygous for her blue color (yy), create a Punnett square to show what
color their children would possibly be.
What percentage of their baby sponges would be yellow?
What percentage of their baby sponges would be blue?
31. Create a Punnett Square to show the probability of genotype for the following:
Brown fur is dominant over white fur for dogs. Cross a homozygous recessive white fur dog with
a heterozygous brown fur dog:
What percentage of the offspring would have brown fur?
What percentage of the offspring would have white fur?
32. The following Punnett Square has a mistake, please circle the mistake:
R
r
R
r
33. Has genetics been hard or easy for you? Please explain your answer:
34. What is DNA? Why is it so important?
35. Using the terms proteins and amino acids describe why scientists call DNA the blueprint of life.
36. Draw a strand of DNA and label at least 10 nitrogen bases. Remember only certain nitrogen bases
pair up with other nitrogen bases.
37. What is a genetic mutation? How do you get these mutations? Do you pass them on to your
children someday?
38. What is a genetic disorder? What are some different ways you might inherit a genetic disorder?
39. List and briefly describe 5 examples of genetic disorders.
40. What is the genotype for a male? What is the genotype for a female?
41. What is gene therapy?
42. How can a bacteria that reproduces asexually develop new traits over time?
43. Who is Gregor Mendel?
44. How many base pairs are in the DNA in just one of your cells?
45. According to the University of Utah’s website when your DNA is copying itself either when
reproduction occurs (meiosis) or when a new cell is forming (mitosis) there are approximately 120,000
mistakes made by the proteins that copy your DNA. Using your answer from problem #44 what is the
percentage of mistakes made by this protein.