Exam questions I got wrong

Question 1

what bond forms between two nitrogenous bases holding two polynucleotide chains together?

Answer 1

hydrogen

Question 2

what ion is required for the hydrolysis of starch by an enzyme?

Answer 2

cl-

Question 3

ventilation is a process involving various parts of the body.
describe the movement of ribcage and external intercostal muscles and the diaphragm during exhalation

Answer 3

ribcage moves inwards and downwards
eternal intercostal muscles contract
diaphragm contracts

Question 4

how is colorimeter calibrated?

Answer 4

distilled water to set it to zero

Question 5

name the bond in a tertiary structure protein that holds two cysteine amino acids linked?

Answer 5

disulphide

Question 6

what immunity does a vaccine provide?
natural or artificial?
active or passive?

Answer 6

artificial active

Question 7

is adenine a pyrimidine?

Answer 7

NO a purine

Question 8

Tubilin protein found in all eukaryotes and some prokaryotes.
explain how genetic code in gene of tubulin codes for the protein tubule?
(2 marks)

Answer 8

genetic code degenerate , 3 amino acids code for more than one protein
base sequences determine the sequence of amino acids

Question 9

what image colour does a scanning electron microscope display?

Answer 9

black and white

Question 10

what image colour does a laser scanning confocal microscope display?

Answer 10

colourful

Question 11

what colour of image does a transmission electron microscope display?

Answer 11

black and white

Question 12

dna can be extracted from white blood cells. an enzyme is used during this process, what enzyme and why?

Answer 12

protease to break down histones wrapped around the DNA

Question 13

why would standard deviation error bars increase confidence in a conclusion made about a graph?

Answer 13

spread of data used rather than mean
reduced likely affect of anomaly

Question 14

one advantage of using binomial name for species?

Answer 14

see evolutionary link between species

Question 15

explain importance of maintaining biodiversity for the discovery of new antibiotics?

Answer 15

. many drugs made come from plants
. increase chance of developing a new drug

Question 16

definition of personalised medicines?

Answer 16

using genes of individual for medicine

Question 17

definition of synthetic biology?

Answer 17

synthesis of new genes

Question 18

how do you work out percentage uncertainty?

Answer 18

uncertainty / measured value

Question 19

suggest and explain reasons why in the 21st century only 10% of the gene loci are polymorphic in wild populations of cheetah? 3 marks

Answer 19

. gene pool become small due to hunting and disease
. fewer alleles
. reduced genetic diversity