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Question 1

apoptosis

Answer 1

It is used during early development to eliminate unwanted cells

• programmed cell death (natural occurring)
• occurs through shrinking of cytoplasm
• often beneficial
• requires ATP

Question 2

necrosis

Answer 2

• accidental cell death (caused by toxin, trauma)
• occurs through swelling of cytoplasm
• harmful to organism
• does not require ATP

Question 3

Stages of embryonic development

Answer 3

Fertilised egg (day 1), morula (day 3), blastocyst (day 5), gastrula (day 12), embryo (week 3) and foetus (week 8)

Question 4

Fertilised egg

Answer 4

also known as zygote

Question 5

Morula

Answer 5

when zygote undergoes mitosis to become two cells it becomes a morula

Question 6

blastocyst

Answer 6

as the cell becomes to specialise in the uterus it becomes a blastocyst. Has one layer

Question 7

gastrula

Answer 7

has three different layers of cell

Question 8

internal checkpoints

Answer 8

Internal checkpoints are used to repair the cycle if a mutation occurs.
They are active in G1, G2 and metaphase.

Question 9

G1 checkpoint

Answer 9

G1 checkpoint check if there are adequate resources for the cell to divide such as neotides and energy to copy the dna. Also if the cell is large enough to divide and if the nuclei has not been damaged

Question 10

G2 to Mitosis checkpoint

Answer 10

G2 checkpoint checks for adequate resources such as proteins require for mitosis and if the DNA and chromosomes have all been replicated without mistake or damage.

Question 11

Metaphase checkpoint

Answer 11

M checkpoint determines if all the spindle fibre have been correctly attached to the sister chromatids and the chromosomes are aligns at the equator.

Question 12

external cell cycle control

Answer 12

environment factors that have an effect

Question 13

Benign neoplasm

Answer 13

• Cell divide uncontrollably but not as rapid as malignant
• organism controls the growth of the neoplasm to an extent and don’t penetrate the blood or lymph vessels
• does not destroy the surrounding tissues and grow in a capsule

Question 14

Malignant neoplasm

Answer 14

• cells divide uncontrollably
• uncontrolled cell growth breaks out of capsule
• neoplastic cells can spread to other tissues
• destroys the surrounding tissues

Question 15

Proto-oncogenes

Answer 15

are a group of normal genes involved in the regulation of cell division. Mutation of this gene can change them into a oncogenes which induce uncontrolled cell division leading to neoplasms

Question 16

tumor -suppressor genes

Answer 16

Group of genes that code protein involved in the slowing down of cell division, the repair of DNA

Question 17

environment factors

Answer 17

such as exposure or radiation can damage dna

Question 18

Carinogens

Answer 18

A carcinogen is a substance or mixture that causes cancer. there are three types (cancer causing agents): chemical physcial and biological

Question 19

Nondisjunction

Answer 19

a pair of homologous chromosomes has failed to separate at anaphase

Question 20

chromosmal changes

Answer 20

deletion, duplication, inversion, and translocation.

Question 21

polyploid

Answer 21

possessing more than two complete sets of chromosomes

Question 22

Aneuploidy

Answer 22

presence of one or more extra chromosomes or the absence of one or more chromosomes