Unit 8

Question 1

Describe how ultrafiltration occurs in a glomerulus

Answer 1

• high hydrostatic pressure
• Glucose, water and ions pass out
• through small pores in the endothelium
•. and through basement membrane

Question 2

How water and glucose reabsorbed by the proximal convoluted tubule of a nephron?

Answer 2

• water down a concentration gradient • glucose by facilitated diffusion and active transport

Question 3

Why does urine concentration increase as thickness of medulla increase?

Answer 3

• the thicker the medulla, the longer the loop of henle
• the longer the loop of henle, means increase in sodium ion concentration in the medulla
• so more water is reabsorbed from the loop of henle by osmosis

Question 4

How can you carry a qualitative measurement for cloudiness

Answer 4

• use colorimetry
• measure the absorbance
• make sure the volumes of all the water samples in each test tubes are the same

Question 5

Explain the purpose of the marker gene

Answer 5

to show that the gene has been taken up

Question 6

To make a recombinant plasmid, why do we use restriction enzymes to obtain the gene rather than produce the gene from mRNA using reverse transcriptase?

Answer 6

• using restriction enzymes will produce gene complete with promotor sequence
• so the gene can he expressed

Question 7

How do primers ensure a test is specific?

Answer 7

• Primers are only complimentary to sequence of Viral DNA
• DNA polymerase only binds to viral DNA and primers

Question 8

Explain how researchers know what sequence the primers should be

Answer 8

• DNA sequencing

Question 9

Why are shorter primers not used?

Answer 9

• they can bind to other viral DNA
• giving a false positive