Unit Test — Unit test Answers

6 verified answers
1
Free Preview

A pedigree chart for a genetic trait is shown below. The trait of interest is carried by a dominant allele, and individuals expressing the trait are represented by the shaded shapes.How do you know that individual 1 is heterozygous for the trait?

Question illustration
A
The shading of the square indicates that the individual is heterozygous.
B
The shaded square is shown to the left of the unshaded circle.
C
Individual 2 is homozygous recessive, and individuals 5 and 8 did not inherit the dominant trait.
D
Individual 2 is homozygous recessive, and individuals 3 and 7 did inherit the dominant trait.
2
Free Preview

The pedigree traces red-green color blindness. Which family members have red-green color blindness?

Question illustration
A
Sam, Tim, Bella, and Joshua
B
Lisa and Monica
C
Ben, Jenny, Mike, Carol, Katie, and Chris
D
Sam, Joshua, and Tim
3

Which is likely to be the most important contribution of genetic engineering to the practice of selective breeding?

A
making pets that are more docile
B
producing plants that grow same-sized fruit
C
reducing genetic diversity to make harvesting easier
D
developing crops that are more resistant to attack by pests
4

In roses, red flowers and long stems are dominant traits. A rose plant that is homozygous for both red flowers and long stems is crossed with a rose plant that is heterozygous for red flowers and homozygous for short stems. What percentage of the offspring will exhibit red, long-stemmed flowers?

A
25 percent
B
50 percent
C
75 percent
D
100 percent
5

Which represents the cross between parent plants if one is heterozygous and has yellow-colored pods and the other is homozygous and has green-colored pods?

A
Yy ´ yy
B
YY ´ yy
C
Yy ´ Yy
D
yy ´ yy
6

The Punnett square predicts the ratio of genotypes in the offspring based on the genotypes of the parents. Which Punnett square represents a cross between a mom who is heterozygous for dimples and a dad who is homozygous for no dimples?

A
A Punnett square is shown. The columns are labeled Upper D and Upper D. The rows are labeled d and d. Clockwise from upper left the boxes contain: Upper D d, Upper D d, Upper D d, Upper D d.
Option A
B
A Punnett square is shown. The columns are labeled Upper D and d. The rows are labeled d and d. Clockwise from upper left the boxes contain: Upper D d, d d, d d, Upper D d.
Option B
C
A Punnett square is shown. The columns are labeled Upper D and d. The rows are labeled Upper D and d. Clockwise from upper left the boxes contain: Upper D Upper D, Upper D d, d d, UpperD d.
Option C
D
A Punnett square is shown. The columns are labeled Upper D and Upper D. The rows are labeled Upper D and Upper D. Clockwise from upper left the boxes contain: Upper D Upper D, Upper D Upper D, Upper D Upper D, Upper D Upper D.
Option D
7

Laura's mother is shown in the image. Which trait is Laura least likely to inherit from her mother?

Question illustration
A
brown eyes
B
pink hair
C
unclefted chin
D
no freckles
8

Which process is the opposite of inbreeding?

A
pollination
B
hybridization
C
seed production
D
genetic engineering
9

Who would be the best people to study to help assess how genetics and the environment influence the expression of traits?

A
identical twins that were adopted and raised by different families
B
identical twins that were raised together by their mother and father
C
a brother and sister that were adopted and raised by different families
D
a brother and sister that were raised together by their mother and father
10

Round seeds and yellow seed color are dominant to wrinkled seeds and green seed color. Which Punnett square represents the correct way to set up the cross RRYy ´ RrYY?

A
A 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R y, r Upper Y, r y. The rows are labeled Upper R Upper Y, Upper R y, r Upper y, r y.
Option A
B
A 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R y, r Upper Y, r y. The rows are labeled Upper R Upper Y, Upper R y, Upper R Upper y, Upper R y.
Option B
C
A 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R Upper Y, r Upper Y, r Upper Y. The rows are labeled Upper R Upper Y, Upper R y, Upper R Upper Y, Upper R y.
Option C
D
A 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R Upper Y, r Upper Y, r Upper Y. The rows are labeled Upper R Upper Y, Upper R Upper Y, Upper R Upper Y, Upper R Upper y.
Option D
11

A cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. Purple offspring result due to incomplete dominance. Then, two of the purple offspring are crossed. What proportion of the offspring from the second cross will be purple?

A
1 in 4
B
2 in 4
C
3 in 4
D
4 in 4
12

The diagram represents a dihybrid cross between two pea plants heterozygous for both seed color and seed shape.What is the phenotypic ratio of the offspring?

Question illustration
A
1:1:1:1:2:2:2:2:4
B
1:3:3:9
C
1:4
D
4:12
14

Some flowering plants appear to have offspring that have traits that are intermediate between those of the parents. Which type of dominance is exhibited by the offspring?

A
complete dominance
B
blended dominance
C
codominance
D
incomplete dominance
15

Svetlana and her mother are very similar. Both have blonde hair, a love of scrapbooking, blue eyes, and a thin nose. Which statement most likely describes Svetlana’s traits?

A
Svetlana inherited her love of scrapbooking from her mother, but her blue eyes come from her environment.
B
Svetlana inherited her blue eyes from her mother, but her love of scrapbooking comes from her environment.
C
Svetlana inherited her thin nose from her mother, but her blonde hair comes from her environment.
D
Svetlana inherited her blonde hair from her mother, but her thin nose comes from her environment.

Did you find these answers helpful?