quetsions idk 2

Question 1

why does facilitated diffusion requires no metabolic energy

Answer 1

-particles have their own kinetic energy so can move down a conc grad.

Question 2

explain why glucose cannot pass through a cell

Answer 2

glucose is a large molecule and the phospholipid bilayer acts as a barrier

Question 3

how do pond leaf’s provide support

Answer 3

• air spaces gives buoyancy.

- supported by surrounding water

Question 4

whats the shape of sieve tube elements

Answer 4

hexagonal/ angular

Question 5

autoimmune disease definition

Answer 5

-abnormal immune response against tissues normally in the body

Question 6

state the 3 reasons biodiversity needs to be maintained

Answer 6

• economic reasons
• aesthetic reasons
• ecological reasons

Question 7

advantages and disadvantages of species that have not been habituated

Answer 7

-more likely to be wiped out by disease
-poaching= more likely
+ less likely to catch disease
+ exhibit natural behaviour

Question 8

sources of error in potometer investigation

Answer 8

• leaks in apparatus

- shoot not cut underwater

Question 9

describe how charged particles move across the plasma membrane

Answer 9

• via facilitated diffusion down a concentration gradient

- via active transport, this is against a concentration gradient, using ATP, using a transport or carrier proteins

Question 10

whats the first line of the secondary defence

Answer 10

phagocytosis

Question 11

T helper cells

Answer 11

• release cytokines that stimulate B cells to develop and stimulate phagocytosis by phagocytes

Question 12

T killer cells

Answer 12

cytotoxic- attack and kill host body cells

Question 13

T memory cells

Answer 13

provide long term immunity

Question 14

T regulator cells

Answer 14

shut down the immune response after a cell has been successfully removed, they are also involved in preventing immunity.

Question 15

what does a thick waxy cuticle in xerophytes do

Answer 15

reduces loss of water vapour through epidermis

Question 16

what does few air spaces in spongy mesophyll in xerophytes do

Answer 16

-reduces surface area for evaporation

Question 17

what does the systemic system carry

Answer 17

carries blood to body

Question 18

what does the the pulmonary system carry

Answer 18

carries blood to the lungs

Question 19

why is the left ventricle larger than the right ventricle

Answer 19

• cus their walls have to be thicker.
• the left side pumps blood to the body
• there is a high pressure

Question 20

resolution and mag of optical

Answer 20

200nm

x1500

Question 21

present or absent in a neutrophil:

• nucleus
• lysosomes
• mitochondria

Answer 21

all present

Question 22

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

Answer 22

Cl-

Question 23

what are the two extracellular enzymes

Answer 23

• amylase

- trypsin

Question 24

what ion does carbonic anhydrase have attached to it

Answer 24

zinc ion

Question 25

talk about the nature of zinc ions in carbonic anhydrase

Answer 25

they are inorganic ions and prosthetic groups

Question 26

whats an intracellular enzyme

Answer 26

catalase

Question 27

what do biosensors do

Answer 27

they take a biological or chemical variable and convert it to an electrical signal

Question 28

how can a student reduce the uncertainty of their data

Answer 28

-use more precise apparatus

Question 29

what is needed for a hydrolysis reaction

Answer 29

water

Question 30

whats an anabolic reaction

Answer 30

when energy is used to synthesise larger molecules

Question 31

whats a catabolic reaction

Answer 31

metabolites are broken down into smaller molecules and release energy

Question 32

why was there rise to the 3 domain system instead of the 5 kingdom

Answer 32

• 4 of the 5 kingdoms are eukaryotic
• bacteria and archaea are different from each other
• 3 domain system more accurately reflects phylogeny
• more evidence than before

Question 33

what does a condensation reaction produce

Answer 33

H2O

Question 34

why does glucose cause a colour change in the benedict’s test

Answer 34

-because glucose is a reducing sugar

Question 35

when doing a benedict’s test on fruit drink, how could results be more valid

Answer 35

• same conc of benedicts being used
• same vol of fruit drink being used
• use of excess benedicts

Question 36

what atoms is DNA made up of

Answer 36

C, H, N ,O ,P ,

Question 37

what type of molecule is DNA

Answer 37

nucleic acid / polynucleotide

Question 38

what type of monomer is DNA made up of

Answer 38

mononucleotide

Question 39

what bond is DNA joined by

Answer 39

phosphodiester

Question 40

how could African elephants be conserved in situ- what measurements should be taken here to conserve them

Answer 40

• creating a nature reserve
• preventing the destruction of the habitat
• monitoring and ensuring enough food is available

Question 41

why is antibodies crossing into the placenta passive immunity

Answer 41

-as the foetus does not produce its own antibodies

Question 42

define species (2)

Answer 42

-organisms that are bale to interbreed with each other and produce fertile offspring, they ahve simmilar phylogeny

Question 43

potential benefits to agriculture of maintaining biodiveristy

Answer 43

• maintains pollinators
• genetic variation=== allows for selective breeding
• variety useful in changing climate
• sources of new medicine

Question 44

explain why crops growing in new climates is bad

Answer 44

• could encounter new diseases
• crops have little resistance
• higher number of pests

Question 45

example of passive natural immunity

Answer 45

• antibodies in breast milk/ across the placenta

Question 46

examples of passive artificial immunity

Answer 46

• anti-venom

- needle stick injections

Question 47

examples of active natural

Answer 47

-humoral response to infection- physical contact with pathogen

Question 48

examples of active artificial

Answer 48

vaccination