3.4

Question 1

Chromosomes

Answer 1

Structures within the cell body that are made up of DNA. DNA consists of genes.

In a human, nearly every cell contains 23 pair of chromosomes. (1 mother/1 father)

Question 2

Genes

Answer 2

The units of heredity that help determine the characteristics of an organism.

Question 3

Mendel

Answer 3

Selective breeding; pea plants. Plants contained “genes”

Question 4

Dominant Gene

Answer 4

A gene that is expressed in the offspring whenever it is present

Question 5

Recessive Gene

Answer 5

A gene that is expressed only when it is matched with a similar gene from the other parent

Question 6

Genotype

Answer 6

Organism’s genetic makeup.

Question 7

Phenotype

Answer 7

Observable physical characteristics

Question 8

Gametes

Answer 8

Sex cells; contains 1/2 of every chromosome pair

Question 9

Zygote

Answer 9

Fertilized cell, contains 23 pairs of chromosomes

Question 10

Cell Division

Answer 10

1. Chromosomes duplicate

2. Cell divides into 2 new cells with identical chromosome structure

Question 11

Monozygotic twins

Answer 11

Identical twins

Question 12

Dizygotic twins

Answer 12

Fraternal twins

Question 13

Heredity

Answer 13

Transmission of characteristics from parents to offspring by means of genes.