Chapter 7

Question 1

Digestive cells

Answer 1

Shot life span because of their harsh environment.

Question 2

Red blood cells

Answer 2

Can’t survive without nucleus, can’t replicate. Comes from bone marrow through blood vessels.

Question 3

Nerve cells

Answer 3

Can’t reproduce, highly specialised.

Question 4

Histones

Answer 4

Proteins that DNA raps around.

Question 5

G1

Answer 5

Growth of cytoplasm and organelles.

Question 6

S

Answer 6

Replication of DNA (chromosomes)

Question 7

G2

Answer 7

Growth in cell size, preparation for mitosis.

Question 8

Prophase

Answer 8

Chromosomes become visible. Spindle fibres start to form.

Question 9

Metaphase

Answer 9

Chromosomes line UN along the equator facing each pole.

Question 10

Anaphase

Answer 10

Chromatids separate and become chromosomes. The spindle fibres contract.

Question 11

Telophase

Answer 11

The nucleus forms and the chromosomes start to unwind.

Question 12

Cytokinesis

Answer 12

In plant cells and animal cells it’s when the membranes separate them.

Question 13

DNA

Answer 13

Deoxyribonucleic acid

Question 14

Spindle fibres

Answer 14

Microtubules

Question 15

Kinetochores

Answer 15

The stuff that the spindle fibres attach to and surround the centreme.

Question 16

Cell plate

Answer 16

Cytokinesis in plants. Barrier in between the two new cells.

Question 17

Cleavage

Answer 17

Cell membrane in animals cells for cytokinesis. When they form up its cleavage furrow.

Question 18

Binary fission

Answer 18

Replication of organelles.

Prokaryotes: Replicates single strand of DNA and then separates.

Question 19

Apoptosis

Answer 19

Suicide of a cell

Eg, tadpole tail.

Question 20

Caspases

Answer 20

Enzyme that activates apoptosis

Question 21

Blebs

Answer 21

Membrane brake down, growths off the plasma membrane.

Question 22

When does apoptosis occur?

Answer 22

When it’s old or infected

Question 23

When apoptosis goes gong what happens?

Answer 23

Cancer forms. Can form from mutated genes.

Question 24

Necrosis

Answer 24

Cell death from external factors.

Question 25

Macrophage………… phagocytes

Answer 25

White blood cells. Use enzymes and lysosomes to brake down debris.

Question 26

Proto-oncogenes

Answer 26

They code cell dividing Proteins. Regulate apoptosis, if uncontrolled courses cancer.

Question 27

Mutagen

Answer 27

An agent that increase the frequency of mutation in DNA.

Question 28

Carcinogen

Answer 28

A cancer coursing agent.

Question 29

Teratogen

Answer 29

An agent that courses physics lesson defects in a developing foetus.

Question 30

Chemical mutagen

Answer 30

Cigarette smoke, benzoyl peroxide

Question 31

Physical mutagens

Answer 31

UV radiation, x-Ray’s

Question 32

Biological mutagens

Answer 32

Viruses, hepatitis B, Epstein Barr Virus.

Question 33

Totipotent stem cells

Answer 33

Potential to create any cell necessary.

Before inner cell mass.

Question 34

Multipotent stem cell

Answer 34

Able to produce cells that have a specific function

Eg. Red blood cell. Umbilical cord

Found in bone morrow.

Question 35

Pluripotent stem cells.

Answer 35

Able to create most tissues of an organism.

Eg. Inner cell mass.

Question 36

Germ layer

Answer 36

There are three layers

Endoderm- internal layer
Mesoderm- middle layer
Ectoderm- external layer

Question 37

Blastocysts

Answer 37

When a zygote does division, after 5 days a hollow ball is formed.

Question 38

List three courses of stem cells.

Answer 38

Umbilical cord, embrognic stem cell, adult stem cell

Question 39

Embryonic and adult stem cells.

Answer 39

Embryonic can make any cell.

Question 40

Stem cell therapy.

Answer 40

Nerve cells- spinal cord injury
Bone marrow cells- cancer patients
Skin cells- burns.