Chapter 2

Question 1

Sperm

Answer 1

Male reproductive cell

Question 2

Ovum

Answer 2

Female reproductive cell

Question 3

Gametes

Answer 3

Male and female reproductive cells.

Huge amount genetic info

Question 4

Zygote

Answer 4

Fusion of sperm and ovum. Hour after sperm enters ovum

Question 5

Genes

Answer 5

Basic units of genetic info

Question 6

How many human genes

Answer 6

25,000

Question 7

DNA molecules

Answer 7

Code for all cells in body. Substance genes are made of

Question 8

Chromosomes

Answer 8

Rod shaped bits of DNA organized in 23 pairs. (46 chromosomes)

Question 9

Chromosomes in sex cells

Answer 9

23

Question 10

Mitosis

Answer 10

One cell makes 2 identical.
Most cells reproduce this way

Question 11

Chromosomes in zygote

Answer 11

46

Question 12

Meiosis

Answer 12

Cell division where cells have half number of chromosomes. Gametes (sex cells)

Question 13

Genetic duplicate/ monozygotic twins

Answer 13

Identical twin

Question 14

Less than ___ % of all pregnancies produce twins

Answer 14

3

Question 15

T/f: multiple births are less likely to occur for triplets or higher order multiples

Answer 15

True

Question 16

Why do multiple births occur?

Answer 16

Bit of cells breaks off (monozygotic)

2 eggs are fertilized by different sperm at close time (Dizygotic)

Question 17

What increases chances of multiple births?

Answer 17

Age
Use of fertility drugs

Question 18

Some parts of _____ _____ have the highest rate of Dizygotic births in the world

Answer 18

Central africa

Question 19

T/f having multiple children carries same risk?

Answer 19

No, risk increases with number of babies

Question 20

Which pair determines sex of child?

Answer 20

23rd

Question 21

Dominant trait

Answer 21

Trait expressed

Question 22

Recessive trait

Answer 22

Present but not expressed

Question 23

Genotype

Answer 23

Combination of genetic material present but not visible

Question 24

Phenotype

Answer 24

Genetic info contained and seen

Question 25

Alleles

Answer 25

Gene pairs that govern certain traits. Alternative forms of a gene

Question 26

Homozygous

Answer 26

Similar genes . Both alleles are the same

Question 27

Heterozygous

Answer 27

Each allele for the gene is different