Mock reflection/sept common deadline

Question 1

what stain binds to phosphate group of DNA to make chromosomes more visable under light microscope?

what charge is it and why?

Answer 1

Methylene blue - a positively charged dye

sugar phosphate backbone has a negative charge `

Question 2

what reaction occours in the breakdown of sucrose?
what monosaccharides are produced?

Answer 2

Hydrolysis reaction, producing a glucose and fructose

Question 3

how is atrial fibrilation shown on an ecg

Answer 3

Irregular p wave

Question 4

what does intraspecific continuous mean

Answer 4

intra= between species

cont=Not on a range (e.g colour)

Question 5

from a solution of starch and amylase, out of an iodine, Benedicts, buiret and Emulsion test, which would show a negative result?

Answer 5

the emulsion test

Question 6

Explain how the genetic code in the gene for tubulin codes for the protein tubulin (2 mrks)

Answer 6

• 3 bases code for one amino acid
  -sequence of basses determine primary structure
  -non-overlapping

Question 7

suggest 2 ways tubulin is essential for protein synthesis and protein secretion in eukaryotic cells

Answer 7

• transport of VESICLES in microtubules from RER to golgi apparatus
  -Transport of SECRETORY VESICLE from golgi to plasma membrane

Question 8

max res, image appearance, image colour of laser scanning confocal microscope

Answer 8

res : 200nm
appearance: 2D/3D
colour= colour

Question 9

max res, image appearance, image colour of = SE microscope

Answer 9

res: 3-10 nm
appearance= 3D
colour = black and white (may be digitally edited)

Question 10

max res, image appearance, image colour of TEM

Answer 10

res: 0.5nm
appearance= 2D
colour = black and white

Question 11

why wouldn’t whit blood cells need to be crushed before adding detergent when extracting DNA

Answer 11

Animal cells don’t have cell walls

Question 12

why s detergent used when extracting DNA

Answer 12

To break down the phospholipid bilayer

Question 13

what enzyme should be used to extract DNA

Answer 13

Protease, to break down histones/proteins associated with DNA

Question 14

what is meant by personalised medicine

Answer 14

development of drug treatments linked to genotype

Question 15

what is meant by synthetic biology

Answer 15

Synthesis of new genes/organisms

Question 16

5 ways in which selection of participants in a study of resting tidal volume of boys and girls age 12 - 19 can be completed to make the study more valid

Answer 16

-random selection
-healthy participants
-include a range of fitness / height/ build
-equal boys to girls
-equal numbers of each age group

Question 17

suggest reasons for a (fast) increase in (MRSA)

Answer 17

-not completing entire antibiotic treatment
-over prescription of methicillin
-large % increase due to fast generation rate

Question 18

how does glycogen differ from amylopectin to make it better suited as an energy store for animals

Answer 18

-1-4 glycosidic bonds so very compact
-more free ends (1mrk) where glucose can be added and removed (1mrk) which speeds up glucose hydrolysis (1mrk)

Question 19

describe how to create 4 different enzyme concentrations using tenfold serial dilutions. start by adding 1cm of 1% trypsin and 9cm distilled water

Answer 19

-shake / mix tube
-remove 1cm^3 from tube 1, add this and 9cm^3 distilled water to tube 2
- repeat process for tubes 4 and 3`

Question 20

how to control xoncentration of hydrogen peroxide solution in an experiment

Answer 20

use a know concentration

Question 21

how to use apparatus to conduct study of effect of temperature on rate of reaction of catalase. Liver tissue, water bath, measuring cylinder, hydrogen peroxide solution, stopwatch, bubbles of oxygen shown on diagram

Answer 21

-record starting meniscus/ ensure measuring cylinder is full of water
-add liver to hydrogen peroxide and start stopwatch
-read/check volume of water displaced at 30 second time intervals
-stopwatch

Question 22

how to use temperature coefficient

Answer 22

rate of reaction at temperature X + 10.C / rate of reaction at temperature X .C

(it is usually around 2 for enzymes)

Question 22

how to use temperature coefficient

Answer 22

rate of reaction at temperature X + 10.C / rate of reaction at temperature X .C

(it is usually around 2 for enzymes)

Question 23

4 features of organisms belonging to kingdom protoctista

Answer 23

-autotrophic or heterotrophic
-most are unicellular
-most are aquatic
-eukaryotic

Question 24

when making an evaluation. what do you need at the end?

Answer 24

A conclusion, involving judgement.

Question 25

explain hoe pairing of nitrogenous bases allows identical copies of DNA to be made

Answer 25

-through hydrogen bonding
-If one base is known, it can pair with only one other base
-purine only bind with pyrimidine as they are different sizes

Question 26

outline how the process of DNA replication is completed, following the pairing of nitrogenous bases
(3mrk)

Answer 26

-sugar phosphate backbone reforms
-DNA polymerase
-reaction between phosphate and sugar
-DNA winds into double helix

Question 27

tidal volume

Answer 27

volume of air that moves in and out of the lungs with each resting breath
-around 500cm
-around 15% of vital capacity in lungs

Question 28

inspiratory reserve volume

Answer 28

max ammount of air yo can breathe in over and above a normal inhalation

Question 29

homologous structure

Answer 29

a structure which seems superficially different ( may perform different functions) in different organisms but has the same underlying structure

Question 30

divergent evolution

Answer 30

Divergent evolution represents the evolutionary pattern in which species sharing a common ancestry become more distinct due to differential selection pressure which gradually leads to speciation over an evolutionary time period

Question 31

Convergent evolution

Answer 31

the process by which two species develop similar features despite not sharing a recent common ancestor. Evolutionary biologists explain these similar characteristics as the product of natural selection

Question 32

What part of the heart beat can you hear

Answer 32

Closing of the valves

Question 33

what does the presance of Co2 do to the sigmoidal curve of oxygen association

Answer 33

Shifts it to the right

Question 34

why are booster jabs used (vaccine)

Answer 34

make more memory cells