Cellular Reproduction + Mitosis

Question 1

What happens in unicellular cell division?

Answer 1

Division of one cell that forms two, reproducing an entire organism

Question 2

What happens in multicellular cell division?

Answer 2

Growth, development, and replacement of damaged cells

Question 3

What is a genome?

Answer 3

The total endowment of DNA unique to each species

Question 4

What is binary fission?

Answer 4

Bacteria replicate their chromosomes and distribute them equally into two daughter cells

Question 5

What occurs in prokaryotic division?

Answer 5

Chromosome replication, membrane growth and separation of chromosome copies, cause the bacterium to grow, making the membrane pinch inward and creating a new cell wall

Question 6

What occurs in eukaryotic division?

Answer 6

Replication and distribution of their tens of thousands of genes, a process that is manageable due to genes being packaged into chromosomes

Question 7

What is a chromosome?

Answer 7

Threadlike structures composed of DNA and protein

Question 8

What are gametes?

Answer 8

Sperm and ova

Question 9

How many chromosomes do human gametes contain?

Answer 9

23

Question 10

What is chromatin?

Answer 10

DNA protein complexes form chromosomes that are organized into thin fibers that are folded and coiled

Question 11

How many chromosomes are in human somatic cells?

Answer 11

46

Question 12

What do proteins do?

Answer 12

Maintain the structure and control gene activity

Question 13

What is mitosis?

Answer 13

Nuclear division, where duplicated chromosomes are evenly distributed into daughter nuclei, results in two genetically identical daughter cells

Question 14

What happens before mitosis?

Answer 14

A cell copies its genome by duplicating every chromosome, each of which forms two identical sister chromatids

Question 15

What are sister chromatids?

Answer 15

Identical copies of a chromosome connected at the centromere

Question 16

What happens to sister chromatids during mitosis?

Answer 16

Pulled apart, forming two complete chromosome sets, one at each end of the cell

Question 17

What is mitosis followed by?

Answer 17

Cytokinesis

Question 18

What is cytokinesis?

Answer 18

Division of cytoplasm

Question 19

What does meiosis do?

Answer 19

Halves the chromosome number in gonads (23)

Question 20

What does fertilization do?

Answer 20

Restores chromosome number to 46

Question 21

What is the cell cycle?

Answer 21

A well-ordered sequence of events occurs between the time a cell divides to form two daughter cells and the time those daughter cells divide

Question 22

What is the M phase?

Answer 22

Dividing phase (includes mitosis and cytokinesis)

Question 23

What is the G1 phase?

Answer 23

First growth phase

Question 24

What is the S phase?

Answer 24

DNA synthesis phase, chromosomes are duplicated

Question 25

What is the G2 phase?

Answer 25

Second growth phase

Question 26

How does duration vary in cells?

Answer 26

It depends on the cell type, some may divide each hour while others take more than 24 hours

Question 27

What phase includes most of the cell's growth and metabolic activities?

Answer 27

Interphase (about 90% of the cycle)

Question 28

What phases are included in interphase?

Answer 28

G1 phase, S phase, and G2 phase

Question 29

How many stages is mitosis divided into?

Answer 29

5

Question 30

What are the stages of mitosis?

Answer 30

Prophase, metaphase, anaphase, and telophase

Question 31

What happens in G2 of interphase?

Answer 31

A well-defined nucleus is bound by nuclear envelope, two centrosomes, and loosely packed chromatin fibers that double

Question 32

What happens in prophase?

Answer 32

Nucleoli disappear, chromatin condenses into chromosomes, and a mitotic spindle forms

Question 33

What happens in prometaphase?

Answer 33

Nuclear envelope fragments (which allow microtubules to interact with condensed chromosomes), spindle fibers extend, kinetochores formed

Question 34

What happens in metaphase?

Answer 34

Chromosomes align in metaphase plate

Question 35

What happens in anaphase?

Answer 35

Sister chromatids split

Question 36

What happens in telophase?

Answer 36

Daughter nuclei form, nucleoli reappear, and chromosomes uncoil, nuclear envelope forms around chromosome fragments

Question 37

What happens by the end of telophase?

Answer 37

Cytokinesis begins and the appearance of two daughter cells occurs shortly after mitosis is completed

Question 38

When does cytokinesis begin?

Answer 38

Telophase

Question 39

How does cytokinesis occur in animal cells?

Answer 39

Cleavage furrow forms, and a contractile ring pinches cells into two

Question 40

How does cytokinesis occur in plant cells?

Answer 40

Cell plate formation, new cell wall forms between daughter cells

Question 41

What are the factors influencing cell division?

Answer 41

Culture medium, cell density, and G1 phase regulation

Question 42

What is culture medium?

Answer 42

Essential nutrients and growth factors required

Question 43

What happens if essential nutrients are left out of the culture medium?

Answer 43

Cell will not grow

Question 44

What is cell density?

Answer 44

Density-dependent inhibition: crowding inhibits division

Question 45

Do cancer cells exhibit cell density? Why or why why not?

Answer 45

They do not exhibit tail density due to them being abnormal

Question 46

What is the G1 phase regulation?

Answer 46

Restriction point determining cell division fate. Cells may enter G0 phase (non-dividing)

Question 47

Where does a cell go when it's ready to divide?

Answer 47

S- phase

Question 48

Where does a cell go if it doesn't meet the requirements to divide?

Answer 48

G0 phase

Question 49

What is the ratio for actively dividing cells?

Answer 49

Cytoplasmic volume to genome size

Question 50

Why is cytoplasmic volume to genome size important?

Answer 50

It determines whether a cell will pass the restriction point

Question 51

What do cancer cells not respond to?

Answer 51

Normal growth controls, lead to unregulated division and potential to invade other tissues

Question 52

Where do cancer cells stop dividing?

Answer 52

Radom points instead of at the restriction point in G1

Question 53

What are the characteristics of cancer cells?

Answer 53

Lack of density-dependent inhibition, random stopping points in the cell, ability to form tumors, transformation

Question 54

What is transformation?

Answer 54

Eukaryotic cells converted to unregulated growth

Question 55

What is a benign tumor?

Answer 55

Localized mas

Question 56

What is a malignant tumor?

Answer 56

Can spread (metastasis), defined as cancer