F211-The Cell Cycle & Life Cycles

Question 0

State the processes that occur during interphase

Answer 0

~DNA replication
~checking of DNA/chromosomes/genes for errors
~protein synthesis
~replication of organelles
~ATP production/respiration
~cell growth/increase in cell volume/size

Question 1

Describe the roles of Mitosis

Answer 1

~makes cells
~creates genetically identical cells
~replacement of cells which are genetically identical and therefore perform the same function growth of tissues
~repair of tissues
~asexual reproduction

Question 2

State what happens in Interphase

Answer 2

It is made up of G1, S and G2

G1- protein synthesis, organelles replicated & ATP required

S- DNA replication, ATP required

G2- cell growth, cell increases in size

Question 3

What are the stages of Mitosis?

Answer 3

Prophase, Metaphase, Anaphase, Telophase and Cytokinesis

Question 4

What is the defining feature of a cell in interphase under a microscope?

Answer 4

• There are no visible chromosomes

- There is a dark and large nucleus/Nucleolus

Question 5

His many chromosomes for the nuclei of our cells contain?

Answer 5

46 chromosomes arranged into 23 pairs.

Question 6

Write the diploid number of chromosomes in terms of n

Answer 6

2n

Question 7

Write the haploid number of chromosomes in terms of n

Answer 7

n

Question 8

Define Haploid

Answer 8

A cell or organism that has just one copy of each chromosome

Question 9

Define Diploid

Answer 9

Cells or organisms that have two copies of each chromosome in their nucleus

Question 10

Explain what is meant by a homologous pair of chromosomes

Answer 10

• one maternal and one paternal chromosome.
• carry the same genes.
• carry the same or may carry different alleles (same length).
• the centromere is in the same position.
• they have the same banding pattern

(They pair up in meiosis to form a bivalent)

Question 11

Explain why the genetic material must be replicated before mitosis?

Answer 11

• cells are genetically identical and have the same DNA.

- so both daughter cells receive a full copy.

Question 12

What are the defining features in Prophase under a microscope?

Answer 12

• chromosomes become visible
• there is no Nucleolus
• nuclear envelope is disappearing

Question 13

Outline the events that occur during prophase..

Answer 13

• chromosomes condense, shorten and thicken so they are visible.
• nuclear envelope starts to disintegrate.
• Nucleolus has disappeared.
• centrioles replicate and migrate and spindle fibres start to form.

Question 14

What is the defining feature in a cell in Metaphase under a microscope?

Answer 14

The chromosomes are aligned in the equator making it look dark

Question 15

Outline the events that occur during Metaphase..

Answer 15

-chromosomes attach to the spindle fibres via the centromere-they align on the equator.

Question 16

What are the defining features on a cell in Anaphase under the microscope?

Answer 16

• centromere has split.

- can see the sister chromatids being pulled apart to opposite poles of the cell.

Question 17

Outline the events that occur during Anaphase..

Answer 17

• the centromere splits.

- sister chromatids are pulled apart to opposite poles of the cell.

Question 18

What are the defining features of a cell in Telophase under the microscope?

Answer 18

-the chromatids are on two sides with nuclear envelopes around them.

Question 19

Outline the events that occur during Telophase..

Answer 19

-nuclear envelopes reform around the chromatids at each pole.

Question 20

What are the defining features of a cell in Cytokinesis?

Answer 20

• two deprecate new daughter cells have been formed.

- there is a line down the middle

Question 21

Outline the events that occur during Cytokinesis..

Answer 21

• the cytoplasm splits into two.
• the cell membrane comes in and pinches off to form two new daughter cells.
• the chromatid unravels.

Question 22

Suggest how cell division in plants differs from cell division in animals?

Answer 22

• In cytokinesis in animal cells, the two me daughter cells are made. No cell wall.
• In cytokinesis in Plant cells, they need to form a cell wall. They do not have centrioles. Cytokinesis starts in the centre of the cell. Only cells that complete this are the meristem and cambium.

Question 23

What is the chromosome number in daughter cells in Meiosis and in Mitosis?

Answer 23

Meiosis= 23 chromosomes.

Mitosis = 46 chromosomes.

Question 24

What number of divisions does Meiosis and Mitosis have?

Answer 24

Meiosis = 2 consecutive divisions.

Mitosis = 1 division.

Question 25

What type of cells does Meiosis produce?

Answer 25

Haploid cells (n)

Question 26

What type of cells does Mitosis produce?

Answer 26

Diploid cells (2n)

Question 27

Does Meiosis produce genetically different or identical cells?

Answer 27

Genetically Different cells

Question 28

Does Mitosis produce genetically different or identical cells?

Answer 28

Genetically Identical cells

Question 29

How many cells does Meiosis produce?

Answer 29

4 cells (these are gametes needed for sexual production)

Question 30

How many cells does Mitosis produce?

Answer 30

2 cells

Question 31

Meiosis ….. The chromosome number?

Answer 31

Halves

Question 32

Mitosis …… The chromosome number?

Answer 32

Maintains

Question 33

Fertilisation ….. The chromosome number?

Answer 33

Doubles

Question 34

Outline reproduction in yeast cells..

Answer 34

• the nucleus divides by Mitosis.
• the cell swells on one side(bulges).
• nucleus or organelles move into bud.
• bud pinches off and a cell wall is formed.
• bud becomes a separate copy.