Monohybrid + Dihybrid Crosses

Question 1

How many pairs of autosomes are in a somatic cell?

Answer 1

22

Question 2

What is an autosome?

Answer 2

Non-sex chromosomes

Question 3

How many pairs of sex chromosomes are in a somatic cell?

Answer 3

1

Question 4

What sex chromosomes are there?

Answer 4

X and Y

Question 5

In meiosis, the chromosome number is cut in ________.

Answer 5

half

Question 6

Why are there only 23 chromosomes in a haploid cell?

Answer 6

The mother and father’s gametes can fertilize into a zygote with 46 chromosomes.

Question 7

What are genes?

Answer 7

Code for a particular trait.

Question 8

What are examples of genes?

Answer 8

Eye color, hair color, height, etc.

Question 9

What are alleles?

Answer 9

A form of genes (ex. alleles for brown eyes or blue eyes)

Question 10

What is complete dominance?

Answer 10

Complete dominance is when the dominant allele completely masks the expression of the other allele.

Question 11

What is a recessive allele?

Answer 11

An allele that is dominated by the dominant allele, and ultimately not expressed.

Question 12

A trait can be ________ or ________.

Answer 12

homozygous or heterozygous

Question 13

What does it mean for the trait to be homozygous?

Answer 13

There are two of the same alleles for a gene.

Question 14

What does it mean for the trait to be heterozygous?

Answer 14

There are two different alleles for a gene.

Question 15

What would be first cross between two alleles be referred to as?

Answer 15

The parent generation (or P generation)

Question 16

What would the hybrid offspring of the parent generation be called?

Answer 16

The F1 generation

Question 17

What is the generation following the F1 generation?

Answer 17

The F2 generation.

Question 18

What is a genotype?

Answer 18

The genetic makeup of alleles, or combination of alleles for any given trait.

Question 19

What is a phenotype?

Answer 19

The physical and psychological traits of an organism.

Question 20

The ________ square helps us find all the possible combinations of genotypes.

Answer 20

Punnett

Question 21

Monohybrid crosses involve two alleles for a __________ gene.

Answer 21

single

Question 22

Dihybrid crosses involve _______ genes.

Answer 22

two

Question 23

What is the Law of Independent Assortment?

Answer 23

If genes are located on separate chromosomes, they are inherited independently of each other.

Question 24

We use the _________ method to find gamete combinations.

Answer 24

FOIL

Question 25

What is crossing over?

Answer 25

During Prophase I of meiosis, genes are swapped between homologous chromosomes.

Question 26

What is the random assortment of chromosomes?

Answer 26

During Metaphase I, homologous chromosomes line of RANDOMLY before being pulled apart during anaphase I.

Question 27

What is fertilization?

Answer 27

When the male and female gametes fuse to form a zygote.

Question 28

How many possible gene combinations are in a gamete?

Answer 28

8 million

Question 29

How many possible gene combinations are in a zygote?

Answer 29

64 trillion

Question 30

What is aneuploidy?

Answer 30

Abnormal pairing during meiosis and zygote formation will have abnormal number of chromosomes.

Question 31

What is monosomy?

Answer 31

A fertilized cell is missing a chromosome.

Question 32

What is trisomy?

Answer 32

A fertilized cell has an extra copy of a chromosome.

Question 33

What is the result when homologous chromosomes fail to separate in Meiosis I?

Answer 33

• 2 gametes that lack a chromosome
• 2 gametes with two copies of the chromosome

Question 34

What is the result if sister chromatids fail to separate (Meiosis II)?

Answer 34

• 1 gamete that lacks chromosome
• 2 normal gametes (1 copy of chromosome)
• 1 gamete with two copies of the chromosome