Reproduction

Question 1

What are diploid cells

Answer 1

2n - have two copies of each chromosome

Question 2

What are haploid cells

Answer 2

1n - have on copy of each chromosome

Question 3

What are the five stages of the cell cycles

Answer 3

1. G1
2. S
3. G2
4. M
5. G0

Question 4

What occurs in the G1 phase

Answer 4

• pre-synthetic gap
• cells create organelles for every and protein production and this increases their size
• restriction point - DNA is checked for quality and must be passed for the cell to move into the S phase

Question 5

What is the restriction point in the cell cycle

Answer 5

• occurs after G1 and S phase

- DNA is checked for quality and must be passed for the cell before it moves onto the S phase

Question 6

What occurs in the S phase

Answer 6

• synthesis
• DNA is replicated
• strands of DNA called chromatids are held together at the centromere

Question 7

What occurs in the G2 phase

Answer 7

• post synthetic gap

- there is rather cell growth and replication of organelles in preparation for mitosis

Question 8

What occurs in the M phase

Answer 8

• mitosis

- mitosis and cytokinesis occurs

Question 9

What occurs in the G0 phase

Answer 9

• cell preforms its functions without preparing for division

Question 10

What is the role of p53

Answer 10

• plays a role in the two major checkpoints of the cell cycle
• G1 to S
• G2 to M1

Question 11

What causes cancer to occur

Answer 11

• cancer occurs when the cell cycle control becomes deranged allowing damaged cells to undergo mitosis without regard to quality or quantity of the new cells produced
• may begin to produce factors that allow them to delocalize and invade adjacent tissues or metastasize elsewhere

Question 12

What is the result of mitosis

Answer 12

• produces two genetically identical diploid daughter cells from a single cells
• occurs in somatic cells

Question 13

What kind of cell division do somatic cells undergo

Answer 13

mitosis

Question 14

What are the four phases of mitosis

Answer 14

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

Question 15

What occurs in prophase

Answer 15

• the chromosomes condense
• the nuclear membrane dissolves
• the nucleoli disappear
• centrioles migrate to opposite sides of the cell
• spindle apparatus forms
• kinetochore of each chromosome is contacted by a spindle fiber

Question 16

What occurs in metaphase

Answer 16

• chromosomes line up along the metaphase plate aka the equatorial plate

Question 17

What occurs in anaphase

Answer 17

• sister chromatids are separated and pulled to opposite poles

Question 18

What occurs in telophase

Answer 18

• the nuclear membrane reforms
• spindle apparatus disappears
• cytosol and organelles are split between the two daughter cells through cytokinesis

Question 19

What kind of cell division do germ cells undergo

Answer 19

• meiosis

Question 20

What cells undergo meiosis

Answer 20

• gametocytes aka germ cells

Question 21

What is the result of meiosis

Answer 21

• gametocytes aka germ cells undergo meiosis and produces four non-identical haploid sex cells aka gametes

Question 22

Meiosis has ___ round of replication and ___ rounds of division

Answer 22

• one round of replication

- two rounds of division - reduction and equational division

Question 23

What are homologues

Answer 23

• chromosomes that are given the same number, but are of opposite parental origin

Question 24

What are the phases of meiosis

Answer 24

• Meiosis I - prophase 1, metaphase 1, anaphase 1, telophase 1
• Meiosis 2 -

Question 25

What occurs in meiosis I

Answer 25

- homologous pairs of chromosomes are separated from each other

Question 26

What occurs in prophase I

Answer 26

- the chromosomes condense - the nuclear membrane dissolves - the nucleoli disappear - centrioles migrate to opposite sides of the cell - spindle apparatus forms - kinetochore of each chromosome is contacted by a spindle fiber - homologues come together and intertwine in a process called synapsis - the four chromatids are called tetrad and crossing over occurs

Question 27

What part of meiosis accounts for Mendel's second law of independent assortment

Answer 27

- prophase I | - then crossing over occurs between tetrads

Question 28

What occurs during crossing over

Answer 28

- the four chromatids called tetrads exchange genetic material between one chromatid and material from another chromatid in a homologous chromosome

Question 29

What occurs in metaphase I

Answer 29

- homologous chromosomes line up at opposite sides of the metaphase plate

Question 30

What occurs in the anaphase I

Answer 30

- homologous chromosomes are pulled to opposite poles of the cell

Question 31

What part of meiosis accounts for Mendel's first law of segregation

Answer 31

- anaphase I

Question 32

What occurs in telophase I

Answer 32

- chromosomes may or may not fully decondense and the cells may enter interkinesis after cytokinesis

Question 33

What occurs in meiosis II

Answer 33

- sister chromatids are separated from each other in a process that is functionally identical to mitosis

Question 34

What are sister chromatids

Answer 34

- are copies of the same DNA held together at the centromeres

Question 35

Biological sex is determined by the ___ pair of chromosomes in humans

Answer 35

- 23rd pair - XX female - XY male

Question 36

Which chromosome carries more genetic information - the X or Y

Answer 36

- X chromosome carries a size able amount of genetic information - Y chromosome carries little genetic information

Question 37

What is the SRY gene and which sex chromosome is it on

Answer 37

- SRY gene is the sex determining region Y - causes the gonads to differentiate into testes