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Genetics - Alleles / Dominant / Heterozygous / Phenotypes

Total questions: 18

Worksheet time: 9mins

Name
Class
Date
1.

What is a gene?

a)

A segment of DNA that codes for a particular type of protein

b)

A type of cell in the body

c)

A type of virus that affects DNA

d)

A type of protein found in DNA

2.

What are alleles?

a)

Alternative form of a gene

b)

Segments of RNA that code for proteins

c)

A chromosome

d)

Entire strand of DNA in a chromosome

3.

What does homozygous mean?

a)

Having no alleles for a gene

b)

Having two different alleles for a gene

c)

Having two identical alleles for a gene

d)

Having multiple alleles for a gene

4.

Which allele gets expressed in a heterozygous individual?

a)

Recessive allele

b)

None of the alleles

c)

Both alleles equally

d)

Dominant allele

5.

What is the phenotype of an organism?

a)

The size of an organism

b)

The genetic code of an organism

c)

The physical characteristics that result from the genotype

d)

The number of alleles an organism has

6.

What determines the characteristics we develop?

a)

Exercise habits

b)

Weather conditions

c)

Food we eat

d)

Genes we inherit

7.

How many alleles of each gene do we have?

a)

One

b)

Three

c)

Two

d)

Four

8.

What is the difference between genotype and phenotype?

a)

Genotype and phenotype are unrelated

b)

Genotype is the genetic code, phenotype is the physical characteristics

c)

Genotype is the physical characteristics, phenotype is the genetic code

d)

Genotype and phenotype are the same thing

9.

What is the reason for having different alleles for the same gene?

a)

Variations in chromosome numbers

b)

Due to the environmental factors

c)

Due to the food they eat

d)

Variations in physical characteristics

10.

In genetics, what does dominant mean?

a)

An allele that is rare in the population

b)

An allele that is hidden by another allele

c)

An allele that is never expressed

d)

An allele that is always expressed

11.

What is the term for having two different alleles for a gene?

a)

Heterozygous

b)

Homozygous

c)

Recessive

d)

Dominant

12.

Which allele is expressed in a heterozygous individual?

a)

Recessive allele

b)

Both alleles equally

c)

None of the alleles

d)

Dominant allele

13.

What determines the color of fur in a mouse?

a)

Exercise habits

b)

Food intake

c)

Weather conditions

d)

Genes coding for fur color

14.

What is the term for having two identical alleles for a gene?

a)

Homozygous

b)

Heterozygous

c)

Recessive

d)

Dominant

15.

What is the physical characteristic that results from the genotype called?

a)

Phenotype

b)

Genotype

c)

Chromosome

d)

Chromosome number

16.

What is the term for having one dominant and one recessive allele for a gene?

a)

Homozygous

b)

Heterozygous

c)

Recessive

d)

Dominant

17.

How do mutations in genes affect phenotype?

a)

They have no effect

b)

They always result in a different phenotype

c)

They can alter the phenotype

d)

They only affect genotype

18.

What is the role of alleles in genetic diversity?

a)

They decrease genetic diversity

b)

They have no impact on genetic diversity

c)

They increase genetic diversity

d)

They determine chromosome number