Intro To Cell Division

Question 1

When does cell division occur in humans and other organisms?

Answer 1

Different times in their life.

Question 2

What is the purpose of cell division in unicellular organisms?

Answer 2

It may be used as a form of asexual reproduction.

Question 3

What is the purpose of cell division in multicellular organisms?

Answer 3

May be used in growth, repair, and development, and a different kind of cell division forms gametes.

Question 4

What are gametes?

Answer 4

Reproductive cells used in sexual reproduction.

Question 5

What are the two forms of cell division called?

Answer 5

Mitosis and Meiosis

Question 6

In humans, which form of cell division is more common?

Answer 6

Mitosis.

Question 7

The process of mitosis is used when?

Answer 7

During asexual reproduction and growth.

Question 8

What is mitosis?

Answer 8

The process by which the nucleus of a cell divides to two new nuclei. Each nucleus that is created contains an identical copy of DNA.

Question 9

What is meiosis?

Answer 9

Lthe process by which gametes are created.

Question 10

What are the male gametes called?

Answer 10

Sperm cells.

Question 11

What are the female gametes called?

Answer 11

Egg cells, or ova.

Question 12

Why must the process of meiosis must form cells that have half the amount of DNA as body cells?

Answer 12

Because the egg and sperm will join each other during sexual reproduction.

Question 13

What are genes?

Answer 13

Segments of DNA that codes for a specific trait.

Question 14

What is DNA organized into?

Answer 14

Genes.

Question 15

What does a single DNA molecule have?

Answer 15

Thousands of genes lined up, one after another.

Question 16

Where is the DNA when a cell is not in the process of dividing?

Answer 16

Spread apart within the nucleus, appears grainy.

Question 17

What is chromatin?

Answer 17

The name for the phase of the DNA when it is spread apart in the nucleus and appears grainy.

Question 18

What does the DNA do when a cell is dividing?

Answer 18

Coils up with certain proteins to form a structure called a chromosome.

Question 19

Why is a chromosome made up of exact copies? What are these copies called?

Answer 19

Before the DNA coils up, it is copied. Chromatids.

Question 20

Where do the chromatids attach? What is this area called?

Answer 20

Near the middle at an area called the centromere.

Question 21

How many chromosomes does a fruit fly have?

Answer 21

8.

Question 22

How many chromosomes does a human have?

Answer 22

46.

Question 23

How many chromosomes does a dog have?

Answer 23

78.

Question 24

What does asexual reproduction require?

Answer 24

Only one parent.

Question 25

What kind of organism reproduces asexually?

Answer 25

Unicellular organisms.

Question 26

What does sexual reproduction require?

Answer 26

Two different parent cells from two separate organisms.

Question 27

What does sexual reproduction produce?

Answer 27

Offspring that are genetically different from each parent.

Question 28

How much DNA does sexually reproduces offspring receive from each parent?

Answer 28

50%. Impossible to get more from one parent than the other.

Question 29

Where are gametes produced?

Answer 29

The gonads.

Question 30

What are the gonads?

Answer 30

The sex organs.

Question 31

What is fertilization?

Answer 31

The joining of the nucleus of the male gamete with the nucleus of the female gamete.

Question 32

What does fertilization form?

Answer 32

A single cell called a zygote.

Question 33

What happens to the chromosomes when a sperm cell fertilizes an egg cell?

Answer 33

The chromosomes of both parents are combined.

Question 34

Excepting the sex cells, each human cell has how many chromosomes and why?

Answer 34

46, because two copes of 23 chromosomes.

Question 35

Regarding the x and y chromosomes, which one forms a male? Which one forms a female?

Answer 35

XY is male and XX is female.

Question 36

What are homologous chromosomes?

Answer 36

Chromosomes that have the same gene.

Question 37

Where are homologous chromosomes found?

Answer 37

Each of the twenty three pairs of chromosomes in a human consist of two homologous chromosomes.

Question 38

What can be different about two homologous chromosomes?

Answer 38

There may be a different version of the same gene.

Question 39

Where does each homologous chromosome of a pair come from?

Answer 39

One from each of the two parents.

Question 40

What are body cells that AREN’T gametes called?

Answer 40

Somatic cells.

Question 41

Why are somatic cells called diploid?

Answer 41

Because they have two of each type of chromosome.

Question 42

Why are gametes called haploid?

Answer 42

Becaause they only have one of each type of chromosome.

Question 43

What term to biologists use to represent haploid and diploid?

Answer 43

N for haploid, 2N for diploid.

Question 44

According to the terms for haploid and diploid, what is the status for humans?

Answer 44

N=23,2N=46

Question 45

How are gametes formed?

Answer 45

Meiosis.

Question 46

What is meiosis?

Answer 46

A type of cell division that results in cells with half the number of chromosomes as the parent cell. Used to form gametes.

Question 47

How many rounds of division does meiosis involve?

Answer 47

2.

Question 48

What is a different name for cell division?

Answer 48

Cell reproduction