paper 1 simplified

Question 1

how does bacteria reproduce

Answer 1

binary fission

Question 2

how to make a culture with the aseptic technique

Answer 2

-lift petri dish towards flame
-put drop of culture on agar
-put drops of antibiotics on culture if needed
-tape lid but spareingly to allow aerobic respiration
-incubate at 25 degrees
-use pi r squared to calculate size of culture

Question 3

how does mitosis work

Answer 3

genetic material is duplicated
the nuclear membrane dissolves ,,
the chromosomes line up along the centre of the cell,, both sets of chromosomes are puled to opposite sides of the cell, new nuclei are formed (the nuclei divide)
other sub cellular structures like mitochondria and ribosomes are also duplicated

Question 4

what can stem cells made in bone marrow only specialise into?

Answer 4

blood cells

Question 5

what are embryo clones for

Answer 5

they can be made of a person to harvest stem cells from. These can be used to treat conditions without them being rejected by the patients body

Question 6

how do teeth break down food

Answer 6

mechanically

Question 7

what does saliva contain

Answer 7

amylase

Question 8

what 2 things does the stomach contain and why

Answer 8

hydrochloric acid and enzymes that chemically break down food

Question 9

what does the liver produce and where does it go

Answer 9

bile , stores in the gall bladder, going into the small intestine

Question 10

what does bile do

Answer 10

it emulsifies lipids to form droplets, increasing their surface area

Question 11

what does the pancreas do

Answer 11

secretes amylase which breaks down starch into glucose in the small intestine

Question 12

wheres water absorbed

Answer 12

into the bloodstream in the large intestine

Question 13

wheres nutrients like glucose absorbed

Answer 13

into the bloodstream by the villi in the small intestine

Question 14

amylase is the enzyme that breaks down ___

Answer 14

starch into glucose

Question 15

what are enzymes

Answer 15

special proteins that act as biological catalysts

Question 16

what do carbohydrases break down carbohydrates into?

Answer 16

simple sugars

Question 17

What do proteases break down proteins into?

Answer 17

amino acids

Question 18

what do lipases break down lipids into?

Answer 18

glycerol and fatty acids

Question 19

what does enzymes being specific mean?

Answer 19

they only break down substrates that fit their active site

Question 20

how to increase the rate of reaction of enzymes

Answer 20

increase temp/pH (until active site denatures #whoops)

Question 21

what do you have to remeber about reading optimum temp/ph off a graph

Answer 21

its between two points

Question 22

how to test for starch (ft)

Answer 22

iodine solution turns from orange to black

Question 23

how to test for sugars (ft)

Answer 23

Benedict’s solution turns from blue to green/yelling to orange to brick red (heat?)

Question 24

how to test for protein

Answer 24

biurets reagent turns from blue to purple

Question 25

how to test for lipids

Answer 25

sudan III causes 2 layers to form, the top being brick red

Question 26

what does a double circulatory system mean

Answer 26

blood enters the heart twice everytime it is pumped around the body

Question 27

whats the movement of blood in the heart from the body

Answer 27

vena cava, right atrium, valve , right ventricle, pulmonary artery, lungs , pulmonary vein, left atrium, valve, left ventricle, aorta (to body)

Question 28

why does the left side of the heart have thicker walls?

Answer 28

the pressure required to pump blood to the body

Question 29

where is the pacemaker and what does it do

Answer 29

in the right atrium's walls, theres a group of cells creating electrical pulses that cause the heart to contract (can use artificial if not working)

Question 30

Difference between veins, capillaries and arteries

Answer 30

arteries have thicker walls, and a thinner lumen to widthstand pressure + no valves capillaries are one cell thick to allow fast diffusion between blood and cells

Question 31

whats chd

Answer 31

when the coronary artery becomes blocked

Question 32

Examples of non communicable diseases and what increases the risk of them

Answer 32

diabetes--> obesity & poor diet increase risk CVD-----> diet liver disease --> alcohol cancer ---> a disease caused by genetic mutation in cells causing them to multiply uncontrollably

Question 33

what are xylem cells for

Answer 33

continuous tubes that carry water and dissolved mineral ions upwards:

Question 34

transpiration (one direction) rate increased with:

Answer 34

increased air movements or temperature and decreased humidity

Question 35

which organ is the reproductive one in a plant

Answer 35

the flower

Question 36

what are phloem cells

Answer 36

tubes of cells that carry sugars and other nutrients to where needed: translocation (bidirectional)

Question 37

what does a lack of nitrate ions mean for the plant

Answer 37

nitrates are needed for protein synthesis ,, deficiency = stunted growth

Question 38

what are the layers of a leaf and what are their functions

Answer 38

waxy cuticle--> waterproof to stop water loss from top of leaf upper epidermis ---> transparent to let light through spongey mesophyll --> gaps to facilitate gas exchange palisade mesophyll --> most photosynthesis takes place here vascular bundle --> xylem & phloem lower epidermis --> botom of leaf guard--> change side to control rate of gasses entering and exiting stomata --> holes in lower epidermis to let gases in/out

Question 39

how do viruses reproduce

Answer 39

by inserting genes into cells which causes them to produce more copies.

Question 40

what are protists

Answer 40

single celled - organisms that are transferred by a vector

Question 41

give an example of a fungus and virus that affects plants

Answer 41

rose black spots - causes leaves to fall off Tobacco mosaic virus --> discolours leaves, less chlorophyll, stunted growth

Question 42

how do lymphocytes work

Answer 42

they produce antitoxins to neutralise toxins by pathogens and antibodies that bind to the entigen of a pathogen but only if they fit. These stop viruses from infecting cells and cause them to clump together.

Question 43

How can plants/humans defend against pathogens

Answer 43

skin,, mucus in nose, acid & enzymes in stomach cell wall, waxy cuticle & bark, poison/ thorns

Question 44

whats the disadvantages of antibiotics

Answer 44

difficult to make for specific bacteria and not damage other good bacteria whole course must be taken to kill all bacteria or more resistant bacteria will survive and multiple

Question 45

where does aspirin and penecillin

Answer 45

willow,, mould

Question 46

explain synthetic drugs

Answer 46

hey cost lots of money to develop, put through trials for efficacy, toxicity and dose, tested on cell tissue, then animals then humans

Question 47

what are monoclonal antibodies

Answer 47

Lymphocytes from mice combined with tumour cells to make a hybridoma,, the hybridoma multiplies, producing lots of the same anti-body

Question 48

what is glucose produced in the endothermic photosynthesis reaction used for

Answer 48

respiration, making starch/fat , making cellulose, making amino acids

Question 49

whats the rate of photosynthesis increased by?

Answer 49

increasing temperature increasing light intensity increasing CO2 conc

Question 50

what happens during exercise

Answer 50

heart and breathing rate increase to increase blood flow to supply more oxygen & glucose to enable muscles to contract

Question 50

respiration provides energy for :

Answer 50

chemical reactions warmth movement

Question 51

whats the equation for anaerobic respiration in plants?

Answer 51

glucose ---> ethanol + carbon dioxide (fermentation)

Question 52

what is metabolism

Answer 52

the sum of all reactions in a cell/organism

Question 53

what can metabolism include

Answer 53

glucose ---> starch, glycogen & cellulose for cell walls fatty acids ---> lipids respiration breakdown of excess protein into urea.