Stuff im getting wrong

Question 1

Pathogen transmission methods in plants?

Answer 1

Droplets
Not vectors
Not direct contact

Question 2

Reason, other than epistasis, why phenotype ratio not as expected?

Answer 2

Linkage:
- both alleles occur on same chromosome
- no independent assortment
- so alleles inherited together
- unless crossing over occurs

Question 3

Plant response to infection:

Answer 3

calloses
release of chemicals
abscission
necrosis (rapid death of plant/tissue to limit spread)

Question 4

Reasons why galactose (also glucose) can be sued as a respiratory substrate?

Answer 4

• bonds contain energy
• can be broken by respiratory enzymes
• soluble so can move
• H/OH can form H-bonds w water

Question 5

Why can’t lactose pass across cell membrane when it’s concentration is low?

Answer 5

too big
unable to pass between phospholipids
no/little conc gradient
needs carrier proteins
needs lactose permease

Question 6

How to use colorimeter to find concentration of unknown sample?

Answer 6

calibrate/zero colorimeter using BLANK
get samples of known conc
serial dilution!!
choose filter
construct calibration curve!!
read off unknown conc value

Question 7

DNA barcoding gene for animals? plants?

Answer 7

for animals, section of mtDNA that codes for cytochrome c oxidase enzyme which is a respiration enzyme.
section of chloroplast DNA in plants.

Question 8

What nt involved in sympathetic ns - fight or flight response?

Answer 8

noreadrenaline!

Question 9

what material is used as stationary phase in thin layer chromatography?

Answer 9

silica gel

Question 10

the three types of adaptations are?

Answer 10

anatomical (structural or physical features)

physiological (biological processes within organism)

behavioral (the way organism behaves)

Question 11

How might new phenotype appear? eg stripes on tigers?

Answer 11

regulatory genes control pattern
genes switched on or off during development
recessive epistasis prevents expression of pigment gene

Question 12

allosteric enzymes?

Answer 12

Allosteric Enzyme* - An allosteric enzyme is an enzyme that contains a region (allosteric site) to which small, regulatory molecules (“effectors”) may bind in addition to and separate from the substrate binding site and thereby affect the catalytic activity.

so effector can bind and act as non-competitive inhibitor of enzyme

Question 13

multiple sclerosis effect?

Answer 13

damages schwann cells
damages myelin sheath
no saltatory conduction

Question 14

line or belt transect used to measure distribution - type of

Answer 14

systematic sampling

Question 15

quadrats used to measure abundance of plants - type of
Eq for population size?

(capture mark recapture to measure abundance of animals) (Eq for population size?)

Answer 15

random sampling

number of individuals/area of sample = population size

(number of individuals in first sample x second sample / number of recaptured marked individuals = population size)

Question 16

in environmentally sensitive ecosystems, management is:

Answer 16

• limit area tourists visit
• control livestock movement
• anti-poaching measures
• replanting forests/native plants
• limit hunting through quotas and seasonal bans

Question 17

in peritoneal dialysis urea and mineral ions pass into?

Answer 17

tissue fluid

Question 18

“The hormone hCG can be detected n urine using pregnancy tests. Which of the following properties of hCG allows it to be detected in urine?”
A - hCG is a polar molecule
B - hCG has a molecular mass of less than 69,000
C - hCG is a polypeptide
D - hCG binds to cells using glycoproteins

Answer 18

B - hCG has a molecular mass of less than 69,000

Question 19

name fluid involved in gas exchange in insects

Answer 19

trachEAL fluid

Question 20

why doesn’t cell undergo mitosis

Answer 20

-already specialized
-in resting phase/G0
-shape is too irregular
-cytoskeleton can’t function

Question 21

noradrenaline fuction

Answer 21

increases heart rate
increases blood pressure
widens pupils

Question 22

whats phaeochromocytoma

Answer 22

adrenal gland cancer - causes increase in heart rate

Question 23

benedicts test is usually for

Answer 23

reducing sugars eg glucose, maltose, fructose, galactose, lactose.
All monosaccharides are reducing sugars.

Question 24

benedicts test + HCl tests for non reducing sugar eg sucrose

Answer 24

non reducing sugar eg sucrose, cellulose.

The acid will break down the non-reducing sugars into monosaccharides. then heat and should get same colour changes as normal.

Question 25

Callus vs callose?

Answer 25

Callus is a growing mass of unorganized plant cells.
Callose is deposited between membrane and cell wall to slow pathogen invasion and spread.

Question 26

Why does phloem contain glucose, sucrose and starch?

Answer 26

Glucose: Bc it contains living cells it’ll constantly be respiring therefore contain some glucose.
Sucrose: Lots of sucrose transported in phloem.
Starch: all plant cells store starch, either in chloroplast or amyloplasts, to give plant cells a source of glucose even when photosynthesis isn’t happening eg at night.

Question 27

Some reasons why PCR theoretical yield not achieved?

Answer 27

-temp damage to fragments
-strands may rejoin
-lack of primer/nucleotides
-primers fail to anneal

Question 28

why use alkaline solution in electrophoresis?

Answer 28

solution carries charge/current.

Question 29

Why formation of tissue fluid?

Answer 29

It comes from substances that leak out of blood capillaries (the smallest type of blood vessel). It helps bring oxygen and nutrients to cells and to remove waste products from them. As new tissue fluid is made, it replaces older fluid, which drains towards lymph vessels.

Question 30

Ultrafiltration vs formation of tissue fluid? same vs diff

Answer 30

Same:
-in capillaries
-hydrostatic pressure > oncotic pressure
-blood vessels narrow to maintain high hydrostatic pressure
-neutrophils pass through
-involve basement membranes
-many molecules reabsorbed
Different:
-bowman’s then PCT in kidney vs tissue fluid bathes intercellular space
-not reabsorbed forms urine vs form lymph
-blood filtered through 3 layers vs one layer to form tissue fluid
-knot of capillaries vs network of capillaries

Question 31

Sample insect biodiversity?

Answer 31

Pooter

sweep net
pitfall traps

Question 32

Measuring length using microscope?

Answer 32

Eyepiece graticule and stage micrometer.

Question 33

for method qs

Answer 33

inc statistical test and control variables and HOW they’re controlled

Question 34

Phloem loading/unloading

Answer 34

Glucose converted to sucrose in photosynthesising cells
apoplast route
active transport
cotransport
passive loading via symplast route
role of plasmodesmata
entry of sucrose into phloem

Sucrose in sink converted back to glucose for respiration or starch for storage
conc gradient of sucrose maintained between phloem and cells

Question 35

What processes take place in G2?

Answer 35

-protein synthesis
-organelle replication/synthesis
-energy store increases
-DNA checked for error
-DNA repair

Question 36

Crossing over occurs in?

Answer 36

Prophase 1 in meiosis

Question 37

Role of B memory cells in secondary immune responses?

Answer 37

-divide to form plasma cells
-produce large amounts of antibodies
-destroy pathogens

Question 38

Convergent evolution?

Answer 38

in which distinct lineages independently evolve similar traits

Question 39

Measuring linear dimensions of cell on microscope slide?

Answer 39

-calibration of eyepiece graticule using stage micrometer
-replace stage micrometer with specimen slide and use same magnification
-count number of graticule divisions that cover the linear dimension of the cells and multiply number of graticule divisions by known length of micrometer

Question 40

Explain, with reference to selective breeding, why its important to maintain viable wild populations of crop plant species. (6)

Answer 40

-genetic variation
-genetic resource/gene bank
-source of useful alleles
-can be cross bred with crop varieties
-allow introduction of diff traits
-unknown future requirements
-potentially useful in changing climate
-prevention of inbreeding depression
-promotion of hybrid vigour
prevent dwindling gene pool
-source of replacement if cultivated crop in danger
-egs of all the above