Cellular Reproduction (unit 1)

Question 1

what are the three main cells discussed in bio 30?

Answer 1

germ, somatic and stem

Question 2

what is a germ cell?

Answer 2

line of cells that cause gamates (eggs in females, sperm in men)

Question 3

what are somatic cells?

Answer 3

body cells which have a diploid amount of cells

Question 4

define diploid

Answer 4

two complete sets of chromosome pairs in a cell (one from mother, one from father)

Question 5

how many chromosome pairs do body cells have?

Answer 5

23 pairs, 46 single chromosomes

Question 6

what are stem cells?

Answer 6

cells that are able to differentiate as well as become other types of cells

Question 7

where does sexual reproduction occur?

Answer 7

germ cells

Question 8

what does sexual reproduction introduce?

Answer 8

genetic variation

Question 9

genetic material is found in different forms depending on the stage of the cycle. what are these stages?

Answer 9

chromatin, chromosomes, or chromatids

Question 10

what is chromatin?

Answer 10

a mixture of dna and proteins that make up chromosomes

Question 11

what is a chromosome?

Answer 11

structures made of a protein and a singular dna molecule to carry genetic info.

Question 12

what is a chromatid?

Answer 12

a half of a chromosome, the sister chromatid’s are formed together at a place called the centromere

Question 13

all somatic cells contain ______ pairs

Answer 13

homologous (23 maternal, 23 paternal)

Question 14

what do the first 44 chromosomes do and what are the called?

Answer 14

autosomes, carry genetic coding

Question 15

how many sex chromosomes are there and how do they work?

Answer 15

2 sex chromosomes, determining the sex (male XY, female XX)

Question 16

what are the two processes that take place in the cell cycle?

Answer 16

divison and replication

Question 17

what do cells do during mitosis?

Answer 17

cells divide

Question 18

where does mitosis occur?

Answer 18

somatic cells

Question 19

all of the cells produced by mitosis are __________ in genetic makeup to the original cells

Answer 19

identical

Question 20

what is differentiation in mitosis

Answer 20

when cells become specialized

Question 21

how many phases does mitosis have?

Answer 21

4

Question 22

what are the 4 phases of mitosis?

Answer 22

1. prophase
2. metaphase
3. anaphase
4. telophase

Question 23

explain what occurs during prophase

Answer 23

chromosomes condense, move and create the mitotic spindle

Question 24

explain what occurs during metaphase

Answer 24

chromosomes move to center of the cell, spindle fibers attach to the centromeres

Question 25

explain what occurs during anaphase

Answer 25

chromatids separate and move to opposite poles of the cell. same # of single chromosomes should be at each pole

Question 26

explain what occurs during telophase

Answer 26

chromosomes at opposite ends of the cell, spread out to form chromatin, nuclear envelope reappears

Question 27

what is the main purpose of mitosis?

Answer 27

growth and replace worn out cells

Question 28

what is cytokinesis?

Answer 28

cytoplasm division

Question 29

what are the 4 phases of the cell cycle?

Answer 29

called interphase (G1, s, G2) the mitosis and cytokinesis

Question 30

what is meiosis?

Answer 30

a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes

Question 31

haploid (meiosis)

Answer 31

the presence of a single set of chromosomes in an organism’s cells (23)

Question 32

difference between mitosis and meiosis?

Answer 32

mitosis: produces two genetically identical daughter cells, one from each parent cell
meiosis: produces cells that are genetically unique from the parent and are made up of half as much pf the dna contents

Question 33

where does meiosis take place?

Answer 33

soley in the reproductive tissues of sexually reproducing organisms, takes place in germ cells

Question 34

meiosis involves _____ cell divisions leading to ______ haploid cells formed

Answer 34

two, four

Question 35

mitosis involves ________ cell division, leading to ________ diploid cells

Answer 35

one, two

Question 36

what are the two different kinds of meiosis?

Answer 36

meiosis 1 and meiosis 2

Question 37

what is meiosis 1?

Answer 37

meiosis 1 is the first division and means the number of cells is doubled but the number of chromosomes is not. this results in half as many chromosomes per cell (23)

Question 38

what is meiosis 2?

Answer 38

this division is similar to mitosis, the number of chromosomes remains the same

Question 39

homologous chromasomes

Answer 39

pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical

Question 40

phases of meiosis 1

Answer 40

Prophase I: Chromosomes pair up and exchange segments (crossing over).
Metaphase I: Paired chromosomes line up in the center of the cell.
Anaphase I: Pairs are pulled apart to opposite sides.
Telophase I: Two new nuclei form, and the cell divides (cytokinesis).

Question 41

phases of meiosis 2

Answer 41

Prophase II: New spindle fibers form in each cell.
Metaphase II: Chromosomes line up in the center again.
Anaphase II: Sister chromatids are pulled apart to opposite sides.
Telophase II: New nuclei form, and the cells divide again (cytokinesis).

Question 42

what is disjunction?

Answer 42

disjunction refers to the seperation of homologous chromosomes or sister chromatids during cell division

Question 43

when does disjunction take place in meiosis?

Answer 43

anaphase 1 or anaphase 2