Genetics Part 1 Test Review
1. Who was the first scientist to study inheritance? __Gregor Mendel_________________.
2. What plant did this scientist study? ____Pea plants______________________________.
3. What is a genotype? __A gene pair for a certain trait__________________________.
4. What is a phenotype? __The physical appearance of a trait.________________________.
5. Homozygous means __Both alleles are the same___________________________.
6. Heterozygous means __Each allele is different (one dominant, one recessive)____________.
7. If a trait shows up more often in a population (think of the minions), is it most likely a
dominant trait or a recessive trait? __dominant______________________________
8. If I have the genotype BB, will the dominant or recessive phenotype show?
__dominant_________________.
9. If I have the genotype bb, will the dominant or recessive phenotype show?
__recessive_________________.
10. If I have the genotype Bb, will the dominant or recessive phenotype show?
__dominant_________________.
11. A Punnett square is used to show ___genetic organization/probability in offspring_____.
12. What is a common phenotypic ratio for a heterozygous Punnett Square?
_9:3:3:1______________________
13. How is it that you have genes from your grandparents? ___Your parents got their genetics
from your grandparents. Therefore you have some genes that have been passed down
through your parents you’re your grandparents. Example: I am 6’0” tall and my brother is
6’6”, but my dad is only 6’1” and my mom is 5’10”. One grandfather was 6’3” and the other
was 6’5”. My brother and I have genes from them._____________________.
Mendel’s Laws:
1. What is the Law of Independent Assortment? ___Traits are inherited separately when they
are assorted into gametes._________________________________________
2. What is the Law of Segregation? ___A parent’s genotype is separated into different
gametes._____________________________________________________________________
Genetics Part 1 Test Review
Meiosis
1. Meiosis is _the process by which 4 haploid (n) cells are made________________.
2. Sex cells produced in meiosis are also knows as __gametes____________________.
3. Are gametes haploid or diploid? ____haploid______________________________.
4. A 2n cell is __diploid______________________.
5. An n cell is ___haploid______________________.
6. Are the gametes created in meiosis genetically identical or different? __different______.
7. What happens in sexual reproduction? ____A sperm cell fertilizes an egg cell to create a
zygote. This allows for a lot of genetic variation in a population.____________
8. What happens in fertilization? ___An egg and sperm cell combine__________________
9. Why is sexual reproduction helpful to a species? _GENETIC VARIATION!!!!_____________
10. If a cell is 2n = 8, how many chromosomes will the haploid cell have? ____4___________
Monohybrid and Dihybrid Cross Practice
1. A homozygous dominant mom is crossed with a heterozygous
dad for the trait of eye color. Brown eyes are dominant to blue.
_100__________ % chance of brown eyes
___0________% chance of blue eyes
2. A blue-eyed mom is crossed with a brown eyed dad. The couple
already have a blue eyed child.
____50_______________ % chance of brown eyes
____50_______________% chance of blue eyes
3. Use the
dihybrid cross below
to ofanswer
the questions.
____2:2_______________
Ratio
blue to brown
eyes
R = round, r = wrinkled, Y = yellow, y = green
RrYy x RRyy
Genetics Part 1 Test Review
What is the
of an
being
probability
offspring
round?
___100%________________________
What is the probability of an offspring being yellow? ___0%________________________
What is the phenotypic ratio in this dihybrid? ___8:8________________________
What would the phenotypic ratio be if the cross was RrYy x RrYy?
__9:3:3:1_____________________