Free Printable Genetics Unit

Worksheets

Genetics Unit

Total questions: 71

Worksheet time: 2hrs 33mins

Name

Class

Date

What is your genetic makeup?

phenotype

genetics

genotype

heredity

What type of reproduction results in offspring looking identical to the parent(s)?

sexual reproduction

asexual reproduction

heredity

genotype

phenotype

A homozygous dominant dog with brown fur is crossed with a heterozygous dog with brown fur. What are the percentages of the possible genotypes?

100% BB

75% BB and 25%Bb

50 % BB and 50% Bb

50% Bb and 50% bb

Squidward has light blue skin, and his genotype for this trait is Bb. Would Squidward be considered a purebred or hybrid for light blue skin?

Purebred

Hybrid

Which of the following is a phenotype?

Blue eyes

the passing of genetic traits from parent to offspring.

heredity

trait

gene

allele

Magda is a tall, 11 year old drummer. She has a scar on her right cheek. She is good at swimming. Which of her traits did Magda most likely inherit?

height

the scar

ability to swim

ability to play drums

Two brown eyed parents (Bb) have a baby. What is the chance the baby is blue eyed?

0 %

25%

50%

75%

An allele whose trait only shows up when no dominant allele is present.

hidden allele

dominant allele

recessive allele

present allele

10.

Dominant alleles are represented by a:

Male gene

lowercase letter

recessive trait

capital letter

11.

In a flowering plant species, red flower color (R) is dominant over white flower color (r). What is the genotype of any red-flowering plant resulting from this species?

RR or Rr

12.

Each one of the boxes on the Punnett Square represents what probability of an offsprings' genotype?

25%

10%

13.

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?

25%

50%

75%

14.

Which picture represents a chromosome?

15.

Describe the relationship between a gene and a chromosome.

A gene is a section of DNA and a chromosome is just a long strand of DNA.

A chromosome does not contain genes, it contains DNA.

A gene is a smaller version of a chromosome.

They are not related.

16.

segment of DNA found on a chromosome; determines the inheritance of a particular trait

gene

chromosome

allele

heredity

17.

Sexual reproduction

genetic material is donated from only one parent; offspring are identical to the parent and each other (uniform)

segment of DNA found on a chromosome; determines the inheritance of a particular trait

genetic material is donated from two parents; offspring differ from each parent and each other (diverse)

a state or condition in which everything is regular, homogeneous, or unvarying

18.

small bodies in the nucleus of the cell that carry chemical instructions for reproduction of the cell.

genes

chromosomes

DNA

alleles

19.

1. How are traits transferred from one generation to another? 7.L.4A.1

Sperm and Egg

Sperm only

Egg only

mitosis

20.

1. Heredity information is found in cells. In what part of the cell is this information found? 7.L.4A.1

Nucleus

Chloroplast

Vacuole

Chlorophyll

21.

Two blue butterflies met on a daisy. They are both heterozygous for their blue (B) wing color, which is dominant over yellow(b) wing color. Create a Punnett square to show the possible results of their offspring. 7.L.4A.3

What are the chances of baby butterflies with blue wings?

25%

75%

100%

22.

1. In Mendel’s famous experiments with garden peas, purple flowers are dominant over white. What would be the phenotypic ratio of the cross at below? 7.L.4A.3

purple/white, 1:1

purple/white, 1:2:1

purple/white, 3:1

purple/white, 1:3

23.

1. Referring to Mendel’s famous experiments with garden peas, purple flowers are dominant over white flowers. Which of answer choices BEST describes the genotypic ratio of the cross at right? 7.L.4A.3

one homozygous dominant, two heterozygous, and one homozygous recessive

three heterozygous and one homozygous recessive

three homozygous dominant and one homozygous recessive

24.

1. Study the figure to the left. Which of the squares shows the offspring that will NOT have the ability to roll his tongue? 7.L.4A.3

Square 1

Square 2

Square 3

Square 4

25.

1. Study the image below. This is an example of what type of inheritance? 7L.4A.3

A. Complete dominance

B. Incomplete dominance

Co-dominance

Complete dominance

Incomplete dominance

Co-dominance

26.

A __________________ is a change in the genes of an organism that occurred randomly or as a result of environmental exposure. 7.L4A.5

A. Genotype

B. Mutation

C. Genetically Modified Organism (GMO)

Genotype

Selective Breeding

Mutation

Genetically Modified Organism (GMO)

27.

The physical expression of a gene e.g. brown eyes

Homozygous

Heterozygous

Genetics

Phenotype

28.

Another term for heterozygous

Homozygous

Hybrid

Phenotype

Genetics

29.

Coat color in cats is codominant. Cats can be black (B), yellow (Y) or calico. A calico cat has black and yellow splotches. A female calico is mated with a male black cat. Create a Punnett Square. What are the offspring’s possible genotypes? 7.L.4A.3

BB, YY, and BY

BB and BY

YY and BY

30.

Which is an example of a homozygous dominant genotype?

31.

A species reproduces quickly and are all genetically identical. How does this species reproduce?

Sexually

Asexually

In-vitro Fertlization

Cloning

32.

Is this pedigree's trait recessive or dominant?

dominant

recessive

33.

What allows species that reproduce sexually to be able to survive as a whole better than a species that reproduces asexually?

Variation in the Population

Quick reproduction times

All organisms are clones

Simple organisms use this method

34.

What is Curtis' genotype?

35.

True or False.
Two parents can have the same phenotype but different genotypes.

True

False

36.

True or False.
Genetic diseases are contagious.

True

False

37.

True or False.
An organism can be heterozygous for a recessive trait.

True

False

38.

True or False.
Dominant genes always come from the father.

True

False

39.

Colorblindness is a sex-linked recessive disorder. A normal woman whose father was colorblind marries a man with normal color vision. What percentage of their sons will be colorblind?

25%

50%

100%

40.

Hemophilia is a sex-linked recessive disorder. A woman with hemophilia marries an unaffected man whose father had hemophilia. What percentage of their daughters will have hemophilia?

25%

50%

100%

41.

Colorblindness is a sex-linked recessive disorder. If the daughter of a couple is colorblind, what are the two possible genotypes of her mother?

X^AX^A and X^AX^a

X^AX^A and X^aX^a

X^AX^a and X^aX^a

Cannot be determined

42.

If a trait shows up more commonly in men than women it is probably

not inherited

on the x chromosome and dominant

on the x chromosome and recessive

on a normal body chromosome

43.

What percentage of the female offspring will be a carrier for this recessive disease?

50%

100%

25%

44.

Which of the following is NOT a sex-linked trait?

Color-blindness

Muscular Dystrophy

Huntington disease

Hemophilia

45.

Hemophilia is a recessive x-linked disorder.
Which genotype represents a female who is a carrier for hemophilia?

X^HX^h

X^hX^h

X^HX^H

X^hY

46.

Hemophilia is a recessive x-linked disorder.
Which genotype represents a male with hemophilia?

X^HX^h

X^hX^h

X^HY

X^hY

47.

Which of the following genotypes belongs in the red box in the Punnett square?

X^BX^b

X^bX^b

X^bY

X^BY

48.

Vitamin D resistant rickets (deformed bone formation) is a sex-linked DOMINANT trait. According to the Punnett square, what percentage of female offspring will have the disorder?

25%

50%

100%

49.

Which chromosome contains more genes?

The X chromosome

The Y chromosome

They are homologous, so they contain the same amount of genes.

50.

Males can be heterozygous for sex-linked traits.

True

False

51.

Muscular dystrophy is a sex-linked recessive disorder. A man with muscular dystrophy marries a woman who doesn’t have this disease. Half of their daughters and half of their sons develop this disease. What is the genotype of the mother?

X^NX^N

X^NXⁿ

Xⁿ

X^N

52.

A boy whose parents have normal vision is colorblind. What are the genotypes for his mother and father? Use X^N for normal vision and Xⁿ for colorblindness. Show the Punnett square to support your answer.

X^bY

X^BY

X^BX^B

X^BX^b

X^bX^b

53.

The bison herd on Konza Prairie has a sex-linked trait known as “rabbit hock” in which the knee of the back leg is slightly malformed. A male bull that is normal mates with a cow that is a carrier for rabbit hock. What are his chances of producing a normal male?

25%

50%

100%

54.

The sex of a child is determined by

whether the father's sperm contains an x or y chromosome

whether the mother's egg contains an x or y chromosome

the age of the parents

55.

The visual representation of an individual's chromosomes is a

phenotype

genotype

karyotype

stereotype

56.

Why is the gene for a disease or disorder more likely to be found on the X chromosome than Y?

The X chromosome has many more genes

The Y chromosome has many more genes

57.

Males are more likely to suffer from a sex-linked disease or disorder because

males are the weaker sex

males have less DNA

males have 1 X chromosome, so the disorder is more likely to be expressed

58.

When we say that a woman is a carrier for a genetic disease or disorder it means that

she has 1 gene, but not the disorder

she has 2 genes for the disorder

she can pass the gene only to male children

she can pass the gene only to female children

59.

Why are men 16 times more likely to be color-blind than women?

to be color-blind, you must have a Y chromosome

to be color-blind, all of your X chromosomes must have the gene

color-blindness is caused by testosterone

color-blindness is caused by the same gene as baldness

60.

If a gene is found only on the X chromosome and not the Y chromosome, it is said to be

sex-linked trait

polygenic trait

codominant trait

incomplete dominance trait

61.

What type of inheritance do two alleles have if their traits blend together?

Incomplete Dominance

Co-Dominance

Mendelian Inheritance

Homozygous Inheritance

62.

How are Incomplete Dominance and Co Dominance different than a normal Mendelian cross?

There is no difference

The heterozygous genotype has a unique phenotype

There is no heterozygous genotype

There is only one phenotype regardless of genotype.

63.

A plant shows incomplete dominance in size. A tall plant (TT) is crossed with a medium plant (TS). What fraction of plants will also be tall?

100 %

75%

50%

25%

64.

A roan cow shows co-dominance in fur color (orange and white). What is the phenotype ratio expected if a roan cow and a roan steer mate together?

4: Orange and White

1: Orange : 1 White

2 Orange: 2 Orange and White: 0 White

1: Orange: 2 Orange and White: 1 White

65.

A red flowered plant (RR) breeds with a White flowered plant (WW). The gene for petal color in these plants expresses incomplete dominance. What percentage of the offspring will have pink (RW) flowers?

25%

50%

100%

66.