Genetics Test 1 Review Guide

1. Heredity is __________________

• an organism’s genetic make-up of allele frequency.

• the scientific study of genetics.

• the genetic material that carries information about an organism.

• the passing of traits from parent to offspring through DNA.

Answer explanation

Check your Genetics notes in your notebook or your vocabulary flash cards for the definition.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

2. Where are an organism’s chromosomes located?

• on the genes

• on the alleles

• in the cell membrane

• in the nucleus

Answer explanation

DNA is located in the nucleus of the cell, and chromosomes are made of DNA.

3. Which of the following BEST describes the number of chromosomes in a normal human liver cell?

• 23 pairs of chromosomes

• 46 different types of chromosomes

• 46 male chromosomes and 46 female chromosomes

• 23 original chromosomes and 23 duplicated chromosomes

Answer explanation

Normal body cells each have 46 chromosomes; 23 from each parent.

4. In certain breeds of dogs, deafness is due to a recessive allele (d) of a particular gene, and normal hearing is due to its dominant allele (D). What percentage of the offspring of a normal heterozygous (Dd) dog and a deaf dog (dd) would be expected to have normal hearing?

• 0%

• 50%

• 25%

• 100%

Answer explanation

You may have wanted to create a Punnett square to help you with this answer. Any genotype with even one dominant allele will mask, or cover up, the recessive allele. So, half of the potential genotypes are Dd (heterozygous) and therefore the probability of a hearing/normal dog is 50%,or half.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

5. Hh

• A - Genotype

• B - Phenotype

Answer explanation

Hh is the genetic makeup that will determine the phenotype.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

6. Blue Eyes

• A - Genotype

• B - Phenotype

Answer explanation

Phenoype = physical features

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

7. RR

• A - Genotype

• B - Phenotype

Answer explanation

Homozygous dominant genotype that will determine t phenotype (physical features)

Tags

NGSS.HS-LS3-1

8. Widow's Peak

• A - Genotype

• B - Phenotype

Answer explanation

Phenotype - physical features

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

9. HH

• A - Homozygous

• B - Heterozygous

Answer explanation

Homozygous dominant genotype

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

10. rr

• A - Homozygous

• B - Heterozygous

Answer explanation

r is a recessive allele; two recessive alleles is known as homozygous recessive

Tags

NGSS.HS-LS3-1