1.6 CELL DIVISION

Question 1

prokaryotic cells divide by?

Answer 1

Binary Fission

Question 2

eukaryotic cells divide by?

Answer 2

Mitosis

Question 3

Mitosis is needed for

Answer 3

Growth

Assexual reproduction

Tissue repair

Embryonic development

Question 4

Cell Cycle

Answer 4

the series of events through which cells pass to divide and create two identical daughter cells

Question 5

Interphase

Answer 5

DNa replication

Organelle duplication → for twin daughter cells

Cell growth → cytoplasmic volumen must increase

Transcription/translation

Obtain nutrients →vital cellular materials must be present

Respiration → ATP production is needed

Question 6

G1

Answer 6

Increase the volume of cytoplasm

Rapid protein synthesis to allow cell growth

Organelles produced

Question 7

S

Answer 7

DNA replication takes place

Question 8

G2

Answer 8

Increase the volume of cytoplasm

Protein synthesis to produce proteins needed for cell division

Organelles produced

Question 9

Prophase

Answer 9

DNA supercoils → chromatins condense

Nucelar membrane desitegrates

Spindle fibres start to form

Centrioles move to opposite poles

Question 10

Metaphase

Answer 10

Spindle fibres bind to centromere

Sister chromatids are aligned at the equatorial plate

Question 11

Anaphase

Answer 11

sister chromatids are separated

Question 12

Telophase

Answer 12

Nuclear membrane start to reform at each pole

Spindle fibres disintegrate

Cell elongates in preparation of cytokinesis

Question 13

Cytokinesis in animal cells

Question 14

Cytokinesis in plant cells

Question 15

Mitotic index

Answer 15

a measure of the proliferation status of a cell population

MI = cells in mitosis / total number of cells

Question 16

Cell Cyclins

Answer 16

a family of proteins that control the progression of cells through the cell cycle

Question 17

G1 phase

Answer 17

Cyclin D levels gradually increase

assembles proteins for DNA replication

Question 18

S phase

Answer 18

Cyclin E activates DNA replication

Question 19

G2 phase

Answer 19

Cyclin S promotes progression through the cycle

Question 20

Mitosis

Answer 20

Cyclin B initiates mitosis

Question 21

Tumorigenesis

Answer 21

the formation of a tumor

Question 22

Tumour

Answer 22

mass of cells that divide uncontrollably

Question 23

Malignant tumours

Answer 23

cancerous growth that is often resistant to treatment

It may spread to other parts of the body

Question 24

Benign tumour

Answer 24

usually localised and does not spread to other partos of the body

respond well to treatment

Question 25

metastasis

Answer 25

when a primary tumor detaches form its original location and moves into another

primary tumor → secondary tumour

Question 26

Mutagens

Answer 26

agents that cause gene mutations

potentially causes cancer

Question 27

examples of mutagens

Answer 27

high energy radiation
short-wave ultraviolet light
some viruses
chemicals taht cause mutations (carcinongens)

Question 28

Mutation in a oncogene

Answer 28

causes a malfunction in the control of the cell cycle → uncontrolled cell division → tumour formation

Question 29

oncogene

Answer 29

a gene which in certain circumstances can transform a cell into a tumor cell.