3 - CELL CYCLE

Question 1

why do cells divide?

Answer 1

1. reproduction
2. tissue renewal
3. growth and development

Question 2

what structures divide during cell division?

Answer 2

1. DNA
2. chromosomes
3. nucleus

Question 3

4 stages of interphase

Answer 3

g1, s, g2, g0

Question 4

• normal metabolic activity
• number of cell organelles increases to normal levels and the volume of cytoplasm increases too, eventually reaching mature size
• a cell can remain in this phase indefinitely
• doubling of number of cell organelles
• stage of the cycle where cells stay the longest

Answer 4

g1 phase

Question 5

• Synthesis phase
• DNA and chromosomes replicate inside the nucleus (92 chromosomes / 46 pairs)

Answer 5

s phase

Question 6

• Structures directly involved in mitosis develop
• Preparation phase for cell division

Answer 6

g2 phase

Question 7

• Time-out phase
• Can last for years
• Cells may die, proceed to cell division, or remain specialized

Answer 7

g0 phase

Question 8

When Do Chromosomes Duplicate?

Answer 8

• During the S phase, all the chromosomes duplicate
• When a chromosome duplicates, it produces a replica chromosome referred to as chromatid/sister chromatid

Question 9

where are the sister chromatids joint?

Answer 9

centromere (specifically kinetochore)

Question 10

• The mechanism by which somatic eukaryotic cells produce identical daughter cells
• Produces 2 identical diploid daughter cells
• Involved partition of both cytoplasmic

Answer 10

mitosis

Question 11

four phases of mitosis

Answer 11

• prophase
• metaphase
• anaphase
• telophase

Question 12

• Chromatin condenses into chromosomes by dehydrating and coiling
• 1 chromosome pair = 2 sister chromatids
• Pairing of chromatids happens in this phase
• Nucleolus and nuclear envelope begins to disappear
• Centrosomes divide into 2 centrioles pair, move apart, forms spindle fiber

Answer 12

prophase

Question 13

• During ________, the chromosomes align near the center of the cell called equator
• The movement of chromosomes is regulated by the attached spindle fibers
• Motion similar to tug-of-war
• Longest stage of mitosis

Answer 13

metaphase

Question 14

• The centromere dissolves and releases each chromatid to be pulled by the spindle fibers via the kinetochore
• At the end, each set of chromosomes has reached an opposite pole of the cell, and the cytoplasm begins to divide.
• Shortest stage of mitosis

Answer 14

anaphase

Question 15

• Chromosomes in each of the daughter cells become organized to form two separate nuclei, one in each newly formed daughter cell
• Cleavage furrow forms preparing for complete division

Answer 15

telophase

Question 16

After telophase, the mother cell splits into 2 and produces 2 daughter cells by undergoing?

Answer 16

cytokinesis

Question 17

mitosis control checkpoints

Answer 17

• DNA damage checkpoints
• apoptosis checkpoint
• spindle assembly checkpoint

Question 18

checkpoint that happens during s phase

Answer 18

DNA damage checkpoint

Question 19

• Survivins ensure that mitosis continues instead of apoptosis
• As mitosis begins

Answer 19

apoptosis checkpoint

Question 20

checkpoint that happens during metaphase

Answer 20

Spindle assembly checkpoint

Question 21

uncontrollable cell / continuously dividing cells spread out throughout the body

Answer 21

Metastatic spurt

Question 22

• Specialized type of cell division which reduces the chromosome number by half
• This process occurs in all sexually reproducing eukaryotes both single-celled and multicellular including animals, plants, and fungi

Answer 22

meiosis

Question 23

end of meiosis 1

Answer 23

2 daughter cells with 46 chromosomes each and are no longer identical due to recombinant chromosomes

Question 24

tetrad formation and crossing over

Answer 24

Prophase I

Question 25

Each sister chromatid will link with their homologous chromosome

Answer 25

tetrad formation

Question 26

Interchange of genetic material between homologous chromosomes occurring during Prophase I

Answer 26

crossing over

Question 27

• Tetrads line up at the equator
• 1 sister chromatid is pulled to each polar end

Answer 27

metaphase I

Question 28

• Tetrads line up at the equator
• 1 sister chromatid is pulled to each polar end
• Upon separation of each sister chromatid, 1 will result to a unique sister chromatid

Answer 28

anaphase I

Question 29

• Nuclear envelopes partially assemble around chromosomes
• Spindle disappears
• Cytokinesis divides the cell into two

Answer 29

telophase I

Question 30

Interchange of genetic material between homologous chromosomes occurring during Prophase I

Answer 30

crossing over

Question 31

Same as prophase except:
Sister chromatids are now recombinant

Answer 31

prophase II

Question 32

Each sister chromatid lines up at the equator (2)

Answer 32

Metaphase II

Question 33

• Each individual chromosomes are pulled to opposite poles
• Each developing cell will only get 1 copy of each chromosome

Answer 33

Anaphase II & Telophase II

Question 34

Haploid sperm cell and oocyte are derived from

Answer 34

diploid germ cells

Question 35

process of developing haploid cells (N or 23 chromosomes)

Answer 35

meiosis

Question 36

begins with double number of chromosomes and ends up with 2 diploid cells

Answer 36

first meiotic division

Question 37

reduction of chromosome number since each of the cells from the first division divides again = 4 cells

Answer 37

second meiotic division

Question 38

Substances that may produce physical or functional defects in the human embryo or fetus after the pregnant woman is exposed to the substance

Answer 38

teratogens

Question 39

period where the pregnant woman is most vulnerable to teratogens

Answer 39

1st trimester

Question 40

most common teratogens

Answer 40

Tobacco and cannabis
Arsenic and benzene
Caffeine and alcohol