TOPIC 3: Voice of the Genome

Question 1

What is the role of the nucleus?

Answer 1

contains genetic info as chromatin

Question 2

What is the structure of the nucleus?

Answer 2

double membrane
nucleolus
nuclear pores

Question 3

What is the nucleolus?

Answer 3

dense area where ribosomes are made

Question 4

What is chromatin?

Answer 4

DNA wrapped around histones

Question 5

Describe the structure of mitochondria.

Answer 5

double membrane

inner membrane folded into cristae (large SA/V for respiration)

Question 6

What is the role of the centrosome?

Answer 6

forms mitotic spindle & cytoskeleton

Question 7

Describe the structure of centrosome.

Answer 7

2 centrioles = 1 centrosome

Question 8

What is the role of smooth ER?

Answer 8

synthesis of lipids & hormones

Question 9

What is the role of rough ER?

Answer 9

synthesis of membrane bound or secreted proteins

Question 10

How do you differentiate between rER and sER?

Answer 10

rER has ribosomes

Question 11

What is the role of the golgi?

Answer 11

modification and packaging of proteins

Question 12

What are vesicles?

Answer 12

small membrane-bound sacs for storage and transport of molecules

Question 13

What is the role of the lysosome?

Answer 13

break down of material in cell

Question 14

What is the structure of the lysosome?

Answer 14

single membrane with digestive enzymes inside

Question 15

What is the role of the cytoskeleton?

Answer 15

gives the cell structure and allows it to change shape

Question 16

What is the secretory pathway?

Answer 16

1. Proteins synthesised on rER (+ folded to form tertiary structure and modified, glycosylation)
2. Proteins packaged into vesicles and transported to Golgi
3. Vesicles fuse with Golgi, where protein is modified further
4. Protein packed into secretory vesicles and pinch off to the cell surface membrane
5. Vesicles fuse with cell membrane and exit by exocytosis/transmembrane protein

Question 17

Which organelles can be found in prokaryotes?

Answer 17

circular DNA, cell wall, capsule, food granules, flagellum, pili, plasmid and mesosome

Question 18

What is the prokaryotic cell wall made of?

Answer 18

peptidoglycan

Question 19

What is the role of the slime capsule?

Answer 19

protection & prevention of dehydration

Question 20

What are the food granules?

Answer 20

glycogen & lipids

Question 21

DIfferences between prokaryotes and eukaryotes

Answer 21

prokaryotes don’t have nuclei (circular DNA)

eukaryotes have membrane-bound organelles

Question 22

What does the mitochondria in sperm cells do?

Answer 22

tightly packed

provides ATP for tail movement

Question 23

What does the flagellum do?

Answer 23

propels the sperm

Question 24

What do microtubules do?

Answer 24

keep sperm in suspension for movement

Question 25

What is the role of the acrosome?

Answer 25

storage for enzymes which digest the zona pellucida

Question 26

What is the role of follicle cells?

Answer 26

surround ovum and release chemicals to trigger acrosome reaction

Question 27

What is the role of the zona pellucida?

Answer 27

glycoprotein layer needed for binding of sperm

Question 28

What is the role of the cortical granules?

Answer 28

lysosome which releases enzymes to thicken zona pellucida and prevent further entry of sperm

Question 29

What are the lipid droplets?

Answer 29

food store for embryo

Question 30

Describe the stages of fertilisation

Answer 30

1. Follicle cell releases chemical which triggers acrosome reaction
2. Acrosome membrane fuses with front of sperm cell membrane and digestive enzymes released
3. Enzymes digest zona pellucida
4. Sperm membrane fuses with ovum membrane & nucleus enters ovum
5. Cortical reaction: zona pellucida thickens to prevent entry of other sperm
6. Egg and sperm nuclei fuse - diploid zygote

Question 31

What is the gene locus?

Answer 31

location of genes on a chromosome

Question 32

What is gene linkage?

Answer 32

when genes are located on the same chromosome and aren’t inherited independently