biology bad paper 1

Question 1

whenever there is optical microscope or electron microscope talk abt…

Answer 1

high or low resolution due to wavelenght of light

Question 2

cell wall of fungi

Answer 2

chitin

Question 3

cel wall of bacteria

Answer 3

murein

Question 4

cell wall of algae

Answer 4

cellulose

Question 5

cell wall of plants

Answer 5

cellulose

Question 6

chi squared is use to…

Answer 6

determine if there’s a significant difference between observed and expected results

Question 7

if there is a person infected with HIV doesnt develop AIDS, why do they not develop AIDS?

Answer 7

• more T helper cells
• more activation of beta cells
• which produce antibodies
• to destroy pathogen

Question 8

why mice have higher metabolic rate than horses

Answer 8

• mice have larger SA:V ratio
• so more heat loss per gram
• faster rate of respiration

Question 9

how enzyme can be phosphorylated

Answer 9

• phosphate attaches to enzyme
• released from hydrolysis of ATP
  ATP-> ADP + Pi

Question 10

why death of epithelium reduces gas exchange

Answer 10

• lower SA:V ratio
• longer diffusion pathway
• rate of gas exchange reduced

Question 11

define non-coding base sequence and where they are found

Answer 11

• don’t code for polypeptide
• found between genes

Question 12

evaluate something that results in less transpiration

Answer 12

• don’t know size of stomata
• don’t know how long stomata has been open for
• don’t know if it’s the same (or true) for all species

Question 13

when talking abt surface area always talk about…..

Answer 13

faster/slower rate of diffuion or respiration

Question 14

water around gills gives a what for diffusion
and how is gills better adapted in water than air

Answer 14

large surface area
water denser than air so supports gills

Question 15

how is antibiotic resistance formed

Answer 15

• some bacteria have alleles for resistance
• resistant bacteria survive

Question 16

cholesterol properties in membrane

Answer 16

• makes membrane less fluid
• the more cholesterol there is the less fluid the membrane becomes

Question 17

feautures in prokaryotic cells but not eukaryotic cells

Answer 17

• dna free in cytoplas
• no membrane bound organelles

Question 18

how to form control tube in enzyme controlled investigation

Answer 18

• same volume of buffer solution
• same concentration of substrate
• same concentration of denatured enzymes

Question 19

when designing own investiagtion almost always….

Answer 19

• measure initial and final mass/lenght
• include specified amount of time eg. 2 hours

Question 20

difference between normal cells and RBCs

Answer 20

RBCs don’t have a nucleus

Question 21

why antibiotic not effective against virus

Answer 21

virus do no have metabolic processes

Question 22

positive control

Answer 22

antibiotic- the one that works

Question 23

negative control

Answer 23

water-lets it grow

Question 24

if in doubt about 3rd mark

Answer 24

talk abt rate

Question 25

rate of respiration

Answer 25

stroke volume (SV) = cardiac output (CO) / heart rate (HR). (This equation is used to calculate the amount of blood ejected from the left ventricle of the heart with each heartbeat)

Question 26

Suggest role of named control

Answer 26

Used as a comparison to see effect of named thing

Question 27

if you have 120 amino acids, how many DNA bases are needed to code for it?

Answer 27

120 x 3 =360 (because each base is part of one triplet) (and each triplet codes for an amino acids)

Question 28

During which part of the cell cycle are gene mutations most likely to occur? why?

Answer 28

S phase dna replicates

Question 29

Give two reasons why there are more than 423 bases

Answer 29

-Addition of base by mutation -introns

Question 30

How oxygen travels ?

Answer 30

Oxygen combines to produce oxyhaemoglobin -each haemoglobin molecule transport 4 molecules of oxygen; -high partial pressure of oxygen at lungs; -haemoglobin (almost) 95% / 100% saturated; -haemoglobin dissociated with oxygen more readily -increase acidity allows more O2 to be unloaded; -increase CO2 occur in vicinity of respiring tissue