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Punnett Square Practice 1

Total questions: 20

Worksheet time: 27mins

Name
Class
Date
1.

------is the combination of two alleles that are different from one another.

a)

homozygous

b)

heterozygous

c)

phenotype

d)

trait

2.

The letters that make-up the genetic code for a trait

a)

genotype

b)

heterozygous

c)

phenotype

d)

trait

3.
---- Is the combination of two alleles that are the same
a)
genotype
b)
homozygous
c)
phenotype
d)
trait
4.
The physical appearance of the allele combination the offspring receives
a)
genotype
b)
homozygous
c)
phenotype
d)
dominant
5.
Black fur (B) is dominant. Find the probability of a black offspring in a cross: bb x bb. 
a)
0%
b)
25%
c)
50%
d)
100%
6.
Look at the Punnett Square. What's the probability of having the recessive offspring?
a)
100%
b)
75%
c)
50%
d)
25%
7.
A section of the DNA strand that determines a specific trait
a)
gene
b)
trait
c)
chromosome
d)
allele
8.
Aa, DD, bB, yy are all examples of
a)
genotypes
b)
phenotypes
9.

Which of the following is/are an example(s) of a phenotype? Select all that apply.

a)

tall

b)

purple

c)

AA

d)

wrinkled

e)

bb

10.

Different versions of a trait (tall or short, white or purple) are called

a)

alleles

b)

traits

c)

versions

d)

genes

11.
Dominant or recessive?
tt
a)

Homozygous Dominant 

b)

Homozygous Recessive

c)

Heterozygous

12.
B = brown fur  b = white fur
In the punnett square, what is the probability for white fur? 
a)
0%
b)
25%
c)
50%
d)
75%
13.
T - tall and t = short
In the punnett square below, what belongs in the missing square
a)
tt
b)
Tt
c)
Bb
d)
TT
14.
What is the probability of heterozygous offspring?
a)
25%
b)
50%
c)
0%
d)
100%
15.
What allele combination should go in the missing box?
a)
AA
b)
Aa
c)
aa
d)
none of these
16.
What is the phenotype of the offspring? (A-Brown hair; a-blond hair) 
a)
50 % Brown Hair and 50% Blond Hair 
b)
25 % Brown Hair and 75% Blond Hair 
c)
75 % Brown Hair and 25% Blond Hair 
d)
0% Brown Hair and 100% Blond Hair 
17.
Which of the following genotypes is homozygous dominant?
a)
A
b)
Aa
c)
AA
d)
aa
18.
T - tall and t = short
In the punnett square below, what belongs in the missing square
a)
tt
b)
Tt
c)
Bb
d)
TT
19.
In plants, tall (T) is dominant to short (t). Perform the following cross: Tt x Tt. What is the probability of producing a short plant?
a)
0%
b)
25%
c)
50%
d)
75%
20.
What allele combination should go in the missing box?
a)
AA
b)
Aa
c)
aa
d)
none of these