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Unit 6 - DNA and Genetics Review

Total questions: 18

Worksheet time: 9mins

Name
Class
Date
1.

In humans, attached earlobes (e) is due to a recessive trait and detached earlobes (E) is the dominant trait. What percentage of the offspring of a heterozygous female and a homozygous male would be expected to have detached earlobes?

a)
75%
b)
10%
c)
50%
d)
25%
2.

Refer to the codon chart. The mRNA sequence has the code CAG. It is most likely to bond with a tRNA that has which amino acid?

a)

Stop

b)

Met

c)

Val

d)

Gly

3.

Skin color in humans is a polygenic inheritance system. A woman with the genotype aabbcc mates with a man who is AABBCC what would the offspring genotype look like?

a)
AaBbCc
b)
AaBBcc
c)
aaBBCC
d)
AABBCC
4.

A DNA strand has the following bases: CGT ACG. What are the bases on the complimentary strand?

a)
ATC TGA
b)
TGC GCA
c)
AGT TCA
d)
GCA TGC
5.

What is the name of this process: mRNA to tRNA to protein.

a)
transcription
b)
replication
c)
mutation
d)
translation
6.

Widow's peak (W) is dominant to no widow's peak (w). A woman who is heterozygous for a widow's peak marries a man who does not have a widows peak. What is the probable genotypic ratio of the offspring?

a)

100% Ww : 0% ww

b)

25% Ww : 75% ww

c)

75% Ww : 25% ww

d)

50% Ww : 50% ww

7.

What did the original DNA sequence look like that produced a mRNA strand with the sequence UGC AUU?

a)
GCU UAA
b)
TGC TAA
c)
AGC ATT
d)
ACG TAA
8.

DNA replication is a semiconservative process because one half of the new strand is the parental strand.

a)

True

b)

False

9.

Sickle cell anemia is a recessive trait. If a woman who is homozygous dominant (not affected) marries a man who has sickle cell anemia, what would be true about the offspring's genotype?

a)

A genotype that is different from both parents

b)

The same genotype as both parents

c)

A phenotype that was different from the parents

d)

The genotype of one of the parents

10.

What are the genotypes of the parents (generation 1) in the pedigree?

a)

Dad is homozygous recessive

Mom is homozygous dominant

b)

Both are heterozygous

c)

Both are homozygous recessive

d)

Dad is homozygous dominant

Mom is homozygous recessive

11.

A student crossed a red snapdragon with a white snapdragon and all the resulting offspring were pink. Which of the following describes this type of inheritance?

a)
Incomplete dominance
b)
Complete dominance
c)
Co-dominance
d)
Polygenic inheritance
12.

Proteins are formed in the cytoplasm using genetic instructions from the DNA in the nucleus. How does the genetic information get to the site of protein synthesis?

a)

mRNA traveled from the nucleus to the cytoplasm

b)

tRNA traveled from the nucleus to the cytoplasm

c)

DNA is divided and sent out to the cytoplasm

d)

rRNA is transcribed from the DNA and binds with mRNA to make proteins

13.

Which of the following best describes the concept of a genetic mutation?

a)
A decrease in the number of genes
b)
An increase in the number of chromosomes
c)
A permanent alteration in the DNA sequence
d)
A temporary change in the DNA sequence
14.

Colorblindness is a sex-linked trait in humans (recessive trait). If a father and son are both colorblind and the mother is normal, what is the genotype of the mother?

a)

X^C X^c

b)

X^c X^c

c)

X^C X^C

d)

X^C Y

15.

The diagram shows a pedigree for a recessive disorder. What is the genotype of individual 8?

a)

X^H X^h

b)

X^h X^h

c)

X^H Y

d)

X^h Y

16.

Which of the following indicates that all organisms can be traced back to a common ancestry?

a)

Almost all genes in microorganisms, plants, and animals have the same codons

b)
The concept of separate origins for each species
c)
The idea of unrelated evolutionary paths for different organisms
d)
The theory of individual common ancestry
17.

Which of Mendel's laws best explains why genetic variation occurs in offspring?

a)

Law of Independent Assortment

b)

Law of Segregation

c)

Law of Crossing Over

d)

Law of Meiosis

18.

If an error occurs during transcription but the change still codes for the same codons as before, would there be any change in the phenotype?

a)

Yes

b)

No