Cell Division

Question 1

How is DNA organized in a prokaryotic cell?

Answer 1

one, circular chromosome attached to the inside of the cell membrane

Question 2

How do prokaryotes reproduce?

Answer 2

Binary fission. In this process, a single chromosome makes a copy of itself

Question 3

How is DNA organized in a eukaryote?

Answer 3

housed in the nucleus and tightly packaged into chromosomes.

Question 4

What is mitosis used for in eukaryotes?

Answer 4

Mitosis is used to produce new body cells for growth and healing

Question 5

What are the two main stages of the cell cycle?

Answer 5

interphase, the cell grows and DNA is replicated

mitotic phase, the replicated DNA and cytoplasmic contents are separated and the cell divides.

Question 6

What happens during the three stages of interphase.

Answer 6

G1 Stage
Cells mature but making more cytoplasm & organelles
Cell carries on its normal metabolic activities

S Stage
DNA is copied or replicated

G2 Stage
All cell structures needed for division are made (eg centrioles)
Both organelles & proteins are synthesized

Question 7

What are the functions of spindles and centrosomes.

Answer 7

Spindles- necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis

Centrosomes- duplicates and then, move to opposite ends of the cell.

Question 8

Briefly describe what happens during early prophase of mitosis

Answer 8

The chromosomes become even more condensed, so they are very compact.
The nuclear envelope breaks down, releasing the chromosomes.

Question 9

Briefly describe what happens during metaphase of mitosis.

Answer 9

At this stage, the two kinetochores of each chromosome should be attached to microtubules from opposite spindle poles.
92 Chromosomes on the Metaphase plate

Question 10

Briefly describe what happens during anaphase of mitosis.

Answer 10

Chromosomes lined up in the middle will split
Occurs rapidly
Sister chromatids are pulled apart to opposite pole by fibers
Centromere must break for this to happen.

Question 11

Briefly describe what happens during telophase of mitosis.

Answer 11

Sister chromatids at opposite poles
Spindles disassemble
Nuclear envelope forms around each set of sister chromatids
Nucleolus reappears
CYTOKINESIS occurs
Chromosomes reappear as chromatin

Question 12

Differentiate between cytokinesis in plant cells and animal cells.

Answer 12

Plants cell wall forms at the equator to divide cell

In animal cells, cleavage furrow forms to split cell

Question 13

Briefly describe the types of asexual reproduction.

Answer 13

Binary Fission- The division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original.
Mitosis- Reproduction of cells
Meiosis- Process that leads to the creation of gametes

Question 14

Describe the advantages of sexual & asexual reproduction.

Answer 14

Sexual- Creates more unique offspring

Asexual- Faster and less complex

Question 15

Differentiate between somatic and germ cells.

Answer 15

Germ Cells= specialized for sexual reproduction

Somatic Cells= do not participate in sexual reproduction; ex. skin cells, muscle cells, etc.

Question 16

Differentiate autosomes and sex chromosomes

Answer 16

Autosomes=chromosomes with genes that do not determine sex

Sex chromosomes=have genes that determine sex

Question 17

Differentiate Between diploid and haploid cells.

Answer 17

Diploid=has two sets of chromosomes; somatic cells

Haploid=has one set of chromosomes; gametes

Question 18

Define zygote

Answer 18

cell formed through fertilization; has a combination of genetic material from both parents

Question 19

Define fertilization.

Answer 19

when two gametes fuse with each other

Question 20

Define homologous chromosomes.

Answer 20

chromosomes that are similar in size, shape, and kinds of genes they contain

Question 21

Compare and contrast mitosis & meiosis.

Answer 21

Mitosis creates two daughter cells while meiosis creates four daughter cells.
Mitosis produces diploid cells while meiosis creates haploid cells.
Mitosis daughter cells are genetically identical while meiosis daughter cells are genetically different.

Question 22

Describe what happens in Prophase II

Answer 22

Nuclear envelope dissolves
Chromosomes condense
Both have duplicated centromere and migrate to edges of cell

Question 23

Describe what happens in Metaphase II

Answer 23

the chromosomes line up individually along the metaphase plate

Extra: Nuclear membrane disappears, Microtubules push centrosomes apart and attach chromatids

Question 24

Describe what happens in Anaphase II

Answer 24

Things pull apart

Sister chromatids split

Question 25

Describe what happens in Telophase II

Answer 25

Cytokinesis happens

Four daughter cells form

Question 26

What happens in Prophase I

Answer 26

The chromosomes begin to condense and they also pair up.
Each chromosome carefully aligns with its homologue partner so that the two match up at corresponding positions along their full length.

Question 27

What happens in Metaphase I

Answer 27

homologue pairs—not individual chromosomes—line up at the metaphase plate for separation.

Question 28

What happens in Anaphase I

Answer 28

The homologous pairs are pulled apart

Question 29

What happens in Telophase I

Answer 29

the chromosomes arrive at opposite poles of the cell.

Cytokinesis usually occurs at the same time as telophase I, forming two haploid daughter cells.

Question 30

Briefly describe what happens in late prophase of mitosis.

Answer 30

The mitotic spindle grows more, and some of the microtubules start to “capture” chromosomes.

Question 31

What is crossing over and when does it occur?

Answer 31

Crossing over is the swapping of genetic material that occurs in the germ line.
Paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes cross over one another.
Occurs in Prophase I of Meiosis I.

Question 32

Compare spermatogenesis with oogenesis.

Answer 32

Spermatogenesis
Two divisions produce 4 spermatids
Spermatids mature into sperm
Produce about 250,000,000 sperm per day

Oogenesis
Produce 3 polar bodies that die and 1 egg
Polar bodies die because of unequal division of cytoplasm
Immature egg called oocyte
Starting at puberty, one oocyte matures in an ovum (egg) every 28 days

Question 33

List and describe 3 ways that genetic variation is guaranteed during sexual reproduction.

Answer 33

Crossing over (in prophase I) 
Random assortment of chromosomes (in metaphase I) Random fusion of gametes from different parents.

Question 34

What is cancer?

Answer 34

Cells reproductive at an uncontrolled rate, take up space

It is a form of uncontrolled meiosis.

Question 35

What are Oncogenes?

Answer 35

Genes that control cell cycle and cell growth
Can run the risk of cancer

Ex. Braco-1 Gene in for breast cancer

Question 36

Define Metastasize

Answer 36

Spread to different parts places

Question 37

How to cure cancer?

Answer 37

Chemotherapy
Attacks all rapidly producing cells or all cells in the body
Radiation has a lot of side effects, i.e. Kills both cancer cells and good cells

Create a virus that only attacks cancer cells.
Viruses have only one RNA
Manipulate virus can only kill cancer cells.

Stop prophase by removing the centriole development or spindle fibers. This stops the start of the germ cell reproduction and allows for cells to no longer reproduce

Remove the part of your body that is more vulnerable to cancer