Genetics Test
Read each question carefully and choose the appropriate answer. There is only one answer per question.
Name_________________________________
1.____________ was the father of genetics, who established the basic laws for inheritance and did is
research with the pea plant. (objective 1)
A. Charles Darwin
B. Gregor Mendel
C. James Watson
D. Francis Crick
2. The principle of segregation stats that parent alleles must become separated to produce sex cells. How
many daughter cells are made because of this process? (objective 2)
A. 1 cell
B. 2. Cells
C. 3 Cells
D. 4 Cells
3. What is the probability that the genotype will homozygous recessive when doing a monohybrid
cross?(obejective 3)
A. 0%
B. 25%
C. 50%
D.100%
4. Two heterozygous people marry and plan to have 4 children, what is the probability that all 4 children
will have brown eyes? The probability of having a brown eyed child is 75%. (objective 6)
A. 56%
B. 42%
C. 32%
D. 23%
5. Two parents want to have a child and the probability of having a blue eye child is 100% and the
probability of having a blonde hair child is 75%. What Mendel law is being described? (objective 2)
A. Principal of Segregation
B. Principal of Independent Assortment
C. Law of Dominance
D. Law of Equality
6. In a dihybrid test cross the phenotype ratios goes as follows? (objective 6)
A. 9:2:2:2
B. 9:3:1
C. 1:1:1:1
D. 9:3:3:1
7. In a female human that has the genotype XXXX how many Barr bodies does she have?(objective 4)
A. 1
B.2
C.3
D.4
8. Parent 1 genotype is bb for coat color and the other parent’s genotype is unknown.
After doing a test cross the probability of having a brown coat color is 50%. What is the genotype for the
other parent? (B=black, b=brown) (objective 3)
A. BB
B. Bb
C. bb
D. None of the above
9. A mother is not a carrier for colorblindness but the father is color blind. What is the probability that a
male offspring will be colorblind? (objective 7)
A. 0%
B. 25%
C. 50%
D. 100%
10. A mother is not a carrier for colorblindness but the father is color blind. What is the probability that a
female offspring will be a carrier for colorblindness? (obejective 7)
A. 0%
B. 50%
C. 75%
D. 100%
11. Why would you predict that half of the human babies born will be males and half will be
females?(objective 9)
A. Because of the segregation of the X and Y chromosomes during the male meiosis.
B. Because the segregation of the X chromosome durning female meiosis.
C. Because all eggs contain an X chromosome.
D. Because, on average, one-half of all eggs produce females.
E. Because of the formation of the Barr body during embryonic development.
12. A characteristic of a dominant trait pedigree is (objective 10)
A. Every affected individual has at least one affected parent
B. Affected individuals who mate with unaffected individuals have a 50% chance of transmitting the trail
to each child.
C. Two affected individuals may have unaffected children
D. A&B
E. A, B &C
13). A characteristic of a recessive trait pedigree is (objective 10)
A. Individual who is affected may have parents who are not affected
B. All the children of two affected individuals are affected
C. Two affected individuals may have unaffected children
D. A& B
Match the correct definition to the vocabulary word. (objective 4)
14) Crossing over___BE____
15) Autosomes ___D_____
16) Principle of Segregation ___A_____
17)Locus __AC____
18)Heterozygous ___AE_____
19) Genotype___AB____
A. In order for sexual reproduction to occur, the two alleles carried by an individual parent must become
separated
B) Members of any gene pair segregate from one another independently of the members of the gene pairs
C) Chromosomes other than sex chromosomes
D) Sex chromosomes
E) Physical expression of an organism’s genes
AB) Genetic makeup of an individual
AC) Gene location on a chromosome
AD) Pair of like chromosome
AE) Pair of unlike chromosome
BE) Breaking and rejoining of homologous chromatids
20) For each genotype below determine what phenotypes would be present.
Red flowers are dominant to white(R), Black hair is dominant to blonde(B). (objective 8)
RR_ Red________
BB___Black__________
Rr__RED_______
Bb___Black__________
rr__ White______
bb___Blone__________
Short Answer
1) Give the following phenotypic and genotypic ratios expected in the following test crosses. Show all
work for full credit. (objective 3)
AA X aa
Aa X Aa
Aa X aa
GR___1____
GR___1:2:1______
GR___1:1______
PR____1 ___
PR____3:1_______
PR___1:1______
a
A Aa
a
Aa
A Aa
Aa
A
A AA
a Aa
a
Aa
aa
a
a
A
Aa
Aa
a
aa
aa
2) Create a dihybrid test cross for traits YyRr X YyRr and what is the phenotypic ratio?(obejective 6)
PR_____9:3:3:1_________
YR
YR YYRR
Yr YYRr
yR YyRR
yr YyRr
Yr
YYRr
YYrr
YyRr
Yyrr
yR
YyRR
YyRr
yyRR
yyRr
yr
YyRr
Yyrr
yyRr
yyrr
3) In humans, blood types have three alleles. A is co-dominant with B, and both are dominant to O. If the
parents have the genotypes AO and BO, what are the possible genotypes and phenotypes of the offspring?
(objective 3)
Genotypes___AB, BO, AO, OO__________________________________________________
Phenotypes__A , B, AB and O.___________________________________________________
A
B AB
O AO
O
BO
OO
4)How did Mendel discover the principles of genetics and what are the main ideas of genetics as
discovered by Mendel? (objective 1)
Answers should topics such as
Studied pea plants due to many varieties and control mating
Practiced true-breeding
Introduced the 3:1 phenotype ratio
Concluded
-alternative versions of alleles
-organism inherits two alleles from one parent
-there is a dominant and recessive allele
-character separate during gamete formation