unit 7

Question 1

why do cells divide?

Answer 1

reproduction, growth, repair, and to stay small so that there is more surface area to volume ratio (SA:V) for nutrients to reach the nucleus through diffusion

Question 2

true or false: during the cell cycle, a cell grows, prepares for cell division, and divides to form 2 somatic (body) daughter cells that are diploid (2n) (contains both sets of chromosomes; a set of mom’s chromosomes AND a set of dad’s chromosomes).

Answer 2

true

Question 3

examples of human somatic cells?

Answer 3

skin cells, heart cells, bone cells, muscle cells, blood cells, nerve cells, etc.

Question 4

examples of plant somatic cells?

Answer 4

leaf cells, flower cells, tulip cells, rose cells, etc.

Question 5

true or false: each new cell will start the cycle once

Answer 5

false, each new cell will start the cycle all over again

Question 6

chromatin–

Answer 6

unfolded/uncoiled DNA (stretched out)

Question 7

chromosome–

Answer 7

folded/coiled DNA, the fold/coils are held together by proteins called histones

Question 8

the cell cycle has 2 main stages, what are they called?

Answer 8

interphase (chromatin is visible) and cell division (chromosome is visible)

Question 9

what is the longest phase of the cell cycle?

Answer 9

interphase

Question 10

interphase–

Answer 10

cells grow and carry out their regular functions, chromosomes are copied (duplicated/replicated), cell prepares for division (duplicates all the organelles)

Question 11

G1–

Answer 11

growth 1: make proteins and organelles

Question 12

S phase–

Answer 12

synthesis, DNA is copied/replicated

Question 13

G2–

Answer 13

growth 2: make molecules needed for division

Question 14

homologous chromosome–

Answer 14

chromosomes from mom and dad that are the same size and contain the same gene (type of information, hair color, eye color, hair texture, etc.) at the same place on the chromosome (however, the chromosomes may have different versions of the genes)

Question 15

true or false: the duplicated chromosomes are attached to each other at the centromere, and are called sister chromatids

Answer 15

true

Question 16

how many total chromosomes does a human have?

Answer 16

46 chromosomes in 23 pairs

Question 17

what is the order of mitosis?

Answer 17

prophase, metaphase, anaphase, and telophase

Question 18

prophase (mitosis)–

Answer 18

DNA (chromatin) condenses (coils together) and the chromosomes become visible, nuclear membrane disappears, centrioles separate

Question 19

metaphase (mitosis)–

Answer 19

chromosomes line up in the middle of the cell’s (equator), chromosomes connect to the spindle fibers that were made by the centrioles

Question 20

anaphase (mitosis)–

Answer 20

centromeres divide and spindle fibers begin to shorten, sister chromatids separate and move to opposite poles (apart)

Question 21

telophase (mitosis)–

Answer 21

chromosomes reach the opposite ends (poles) of the cell, nuclear membrane forms again, cell begins to split in half

Question 22

cytokinesis–

Answer 22

cytoplasm splits in half forming 2 identical daughter cells, in animal cells the cell membrane pinches inward creating a cleavage furrow, and in plant cells, a cell plate forms between the 2 daughter cells.

Question 23

how many daughter cells does mitosis produces?

Answer 23

mitosis produces two identical somatic (body) daughter cells

Question 24

true or false: the somatic daughter cells are diploid (contains both sets of chromosomes; a set of mom’s chromosomes and a set of dad’s chromosomes)

Answer 24

true

Question 25

what is cancer caused by?

Answer 25

cancer is caused by abnormal cell cycle, abnormal cell cycle produces mass of cells called tumor, cancer occurs only in multicellular organism like plants, animals, and fungi

Question 26

meiosis--

Answer 26

the process of nuclear division where the number of the chromosomes is halved

Question 27

how many daughter cells are produced in meiosis?

Answer 27

four

Question 28

all daughter cells haploid or diploid in meiosis?

Answer 28

haploid

Question 29

what does meiosis make?

Answer 29

gametes (sperm and egg)

Question 30

independent assortment--

Answer 30

during meiosis, the chromosomes move randomly to separate poles, this means each gamete will have 1 or many different possible combinations of chromosomes

Question 31

crossing over (meiosis)--

Answer 31

chromosomes exchange sections by swapping genetic material between a pair of homologous chromosomes, the chromatids next to each other "cross over"

Question 32

true or false: crossing-over in meiosis decreases variability/diversity

Answer 32

false, crossing over in meiosis increases variability/dirversity

Question 33

true or false: crossing-over in meiosis increases the already huge number of different possible gamete types produced by independent assortment

Answer 33

true

Question 34

spermatogenesis--

Answer 34

production of male gametes (sperm)

Question 35

where does spermatogenesis occur?

Answer 35

occurs in the testes (germ cells), two divisions produce four sperm cells

Question 36

how much sperm does men produce each day?

Answer 36

men produce about 250,000,000 sperm per day

Question 37

oogenesis--

Answer 37

production of female gametes (eggs)

Question 38

where does oogenesis occur?

Answer 38

occurs in the ovaries (germ cells), two divisions produce three polar bodies that die and one egg

Question 39

why do polar bodies die?

Answer 39

because of unequal division of the cytoplasm, and starting at puberty, one egg matures every 28 days

Question 40

1 sperm + 1 egg =

Answer 40

1 zygote

Question 41

true or false: cell division of body cells (somatic) is called mitosis

Answer 41

true

Question 42

true or false: cell division that produces gametes is called meiosis

Answer 42

true

Question 43

how many diploid cells does mitosis produces?

Answer 43

2 diploid cells (2n)

Question 44

how many haploid cells does meiosis produces?

Answer 44

4 haploid cells (n)

Question 45

how many cell division does mitosis have?

Answer 45

one cell division

Question 46

how many cell division does meiosis have?

Answer 46

two cell divisions

Question 47

true or false: in mitosis, all cells are identical

Answer 47

true

Question 48

true or false: in meiosis, all cells are different

Answer 48

true