Cell Cycle + Mitosis

Question 1

What is diffusion?

Answer 1

the movement of particles from an area of high concentration to an area of low concentration

Question 2

Why are cells small?

Answer 2

Cells are so little,so they can maximize theirratio of surface area to volume. Cells are limited in sizebecause the outside (the plasma membrane) must transport oxygen, carbon dioxide and other molecules into and out of the cell.

Question 3

What are the reasons for cell division?

Answer 3

• 1. Reproduction: Cells undergo reproduction to pass on genetic information to new cells
  2. Growth: increase in the number of cells to grow larger
  3. Repair: cells also grow and divide to replace cells lost because of normal wear and tear or injury. Some cells, such as

Question 4

What is the interphase?

Answer 4

Interphase isthe phase of the cell cycle in which a typical cell spends most of its life. Interphase is the “daily living” or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other “normal” cell functions.

Question 5

G0

Answer 5

The resting phase (also called the quiescent or dormant phase)

• The cell performs all of its normal functions but is not prepared to divide.
• Some cells often decide and either are in G0 for à short amount or skip G0. The cells do not divide very often and are in the G0 phase for many years.

When the cell receives the signal to divide it moves into the G1 phase of the cell cycle.

Question 6

G1

Answer 6

Gap 1 - first growth phase

• The cell prepares to undergo cell division
• The cell still performs all of its normal functions but starts to get bigger.
• The cell begins to make à copy of the cell parts (organelles) it also begins to make more promotion to get ready to divide.
• The time for this phase varies from about 8 hrs to several days, weeks or months.

Question 7

G1 complications

Answer 7

• Not large enough
• not enough nutrients
• dna is damaged
• social signals are not present

Question 8

What is g2

Answer 8

Gap 2

• The cell makes more proteins in preparation for cell division
• This phase lasts about 2-5 hours

Question 9

G2 complications

Answer 9

• • chromosomes are not duplicated correctly
  • dna damaged

Question 10

What is Mitosis

Answer 10

• The cell divides into 2 new cells, which occurs in 4 stages ^)
• The mitosis lasts 1- 3 hrs’

Question 11

what is prophase

Answer 11

• nuclear membrane begins to disappear
• chromatin condenses (visible) into sister chromatid
• centrioles move to poles
• Spindle fibres start to form
• Chromosomes first become visible

Question 12

Metaphase

Answer 12

• nucleus dissolves
• chromosomes move together in metaphase plate

Question 13

anaphase

Answer 13

• sister chromatids separate from each other
• spindle fibres shorten and retract and break sister chromatids apart
• cell starts elongating

Question 14

telophase

Answer 14

• cell nearly done dividing/split into 2
• nuclear envelope reforms
• chromosomes decondense

Question 15

Cytokinesis

Answer 15

Cytokinesis isthe physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells

Question 16

Cytokinesis in animals vs plants

Answer 16

plant: cell wall forms in between daughter cells (middle)
animal: cleavage furrow forms

Question 17

karyotype

Answer 17

A karyotype is an individual’s complete set of chromosomes.

Question 18

chromosomes in human

Answer 18

46 chromosomes-23 matching pairs of chromosomes

Question 19

chromatin

Answer 19

mixture of DNA and proteins that is loosely spread throughout nucleus in threadlike form.

Question 20

sister chromatids

Answer 20

two copies of a chromosome are called sister chromatids (identical to each other and attached to each other)
-during synthesis

Question 21

chromosomes

Answer 21

a long piece of coiled DNA and proteins, only visible when the cell is dividing. (prophase and condensed)

Question 22

Centromere

Answer 22

part of a chromosome that links a pair of sister chromatids

Question 23

Centriole

Answer 23

paired barrel-shaped organelles located in the cytoplasm of animal cells

• only visible during cell division such as prophase (helps them to divide or make copies of themselves)
• located in cytoplasm of animal cells only (2)

Question 24

Nuclear envelope

Answer 24

membrane barrier that separates the nucleus from the cytoplasm

Question 25

Spindle fibres

Answer 25

*proteins that pull the chromosomes towards the poles: during metaphase formed between centrioles and centromere of chromosomes
made of microtubules

Question 26

What cell has the longest life span in our body and shortest

Answer 26

Longest: stem cells and neurons

Shortest: sperm, stomach cells and skin cells