Unit 4 Concepts - Cell Cycle

Question 1

Before a cell becomes too large it…

Answer 1

divides into 2 daughter cells; each an exact replica of the parent cell

Question 2

Before a cell divides what is replicated?

Answer 2

DNA

Question 3

Cell death is necessary for?

Answer 3

normal development of cells AND
maintaining regular functions and activities

Question 4

As a tadpole changes into a frog, the cells in the tadpole tail are signaled to undergo…

Answer 4

Apoptosis; involved in metamorphosis
🐸🐸🐸🐸🐸🐸🐸🐸🐸🐸🐸🐸

Question 5

Parts of a Cell Cycle:
Label the Diagram

Answer 5

See Diagram

Question 6

What is the longest part of the cell cycle that requires 90% of the time?

Answer 6

Interphase

Question 7

What is the first stage in Interphase?

Answer 7

G1 - Cells increase and size and to whever the cell is designed to do

Question 8

What is the 2nd stage of Interphase?

Answer 8

S: Synthesis - In this phase DNA is replicated

Question 9

What is the 3rd stage of Interphase?

Answer 9

G2: Gains more energy: sythesis of organelles to prepare for division

Question 10

What are the two stages of cell division?

Answer 10

mitosis = nuclear division AND
cytokinesis = cytoplasm division

Question 11

mitosis is what kind of cell division

Answer 11

nuclear division

Question 12

cytokinesis is what kind of cell division

Answer 12

cytoplasm division

Question 13

What three things parts of a chromosone?

Answer 13

chromatin, chromatid, centromere

Question 14

chromatin

Answer 14

granular material visible within the nucleus; consists of DNA tightly coiled around the protiens

Question 15

chromatid

Answer 15

one of two identical “sister” parts of a duplicated chromosone

Question 16

centromere

Answer 16

an area where the chromatids are attached to one another

Question 17

Label the parts of the chromosone

Answer 17

First Blank: telomere
Second Blank: centromere
Entire Structure: sister chromotid

Question 18

What are the four phases of mitosis or PMAT?

Answer 18

Prophase, Metaphase, Anaphase, Telophase

Question 19

What do the stages of mitosis ensure?

Answer 19

They ensure that each new cell has the same number of chromosomes as the original cell.

Question 20

Is mitosis a continuous process?

Answer 20

yes

Question 21

In prophase, DNA becomes the visible form of what?

Answer 21

chromosones

Question 22

What happens to the nuclear envelope in prophase?

Answer 22

it disappears

Question 23

What happens to centrioles during prophase?

Answer 23

They move to the opposite side.

Question 24

What happens to spinal fibers during prophase?

Answer 24

They are sent out and attache to centromeres.

Question 25

What do spindle fibers to:

Answer 25

They extend from centrioles (at opposite sides of the cell) to centromeres (regions of the chromosomes)

Question 26

What happens during metaphase?

Answer 26

Chromosomes line up across the center of the cell.

Question 27

What happens to centromeres during the anaphase?

Answer 27

The centromeres split

Question 28

What happens to sister chromatids during anaphase?

Answer 28

During anaphase sister chromatids separate and move to the opposite pole by spindle fibers.

Question 29

What is the final result of anaphase?

Answer 29

Each side of the cell has a set of chromosomes identical to the parent cell.

Question 30

What are the three stages of telophase

Answer 30

A: Chromosomes begin to disperse into a chromatin (tangled form of DNA) B: Nuclear envelope reforms around each cluster of chromosomes. C: Spindle fibers begin to break apart.

Question 31

What major event takes place during prophase?

Answer 31

nuclear envelop disappears and chromosome become visible.

Question 32

What major event takes place during metaphase?

Answer 32

chromosomes line up in the center of the cell

Question 33

What major event takes place during anaphase?

Answer 33

sister chromatids separate and move to the opposite ends of the cell

Question 34

What major events takes place during telophase?

Answer 34

chromosomes begin to disperse into chromatin , nuclear envelope reforms and spindle fibers break apart

Question 35

What major events take place in interphase?

Answer 35

DNA is in unraveled chromatin form that is no longer visible. Cell undergoes grown, replicates and gets organelles ready for mitosis.

Question 36

Why do cells have to undergo DNA replication BEFORE mitosis?

Answer 36

each daughter cell needs a copy of the genetic material

Question 37

What are the 2 parts of the cell cycle?

Answer 37

interphase and M-phase

Question 38

What is the "Hayflick" limit?

Answer 38

There is a limit to the number of times a cell can divide; about 50. A cell undergoes apoptosis when the telomere is no longer present.

Question 39

What is the process called when a cell divides into 2 cells?

Answer 39

Cytokinesis

Question 40

Cytokinesis occurs at the same time as

Answer 40

telophase

Question 41

What happens in animal cytocinesis?

Answer 41

The cell membrane pinches in the middle and the the cytoplasm is divided in nearly two equal parts.

Question 42

What happens in plant cytokinesis?

Answer 42

A cell wall forms in the middle of the cell.

Question 43

What is a cyclin?

Answer 43

A protein that regulates the timing of the cell cycle.

Question 44

What are the internal regulators during cell growth?

Answer 44

Proteins that respond to events inside the cell. Example: make sure all chromosomes have been replicated; make sure all chromosomes are attached to the spindle fiber before entering anaphase.

Question 45

What are the external regulators during cell growth?

Answer 45

Proteins that respond to events outside the cell, such as wound healing.

Question 46

When a cell loses the ability to control it's own growth what happens?

Answer 46

The cells reproduce too rapidly become a form of cancer. Masses called tumors develop.

Question 47

What gene halts the cell cycle until chromosomes have been properly replicated?

Answer 47

p53 gene