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Edexcel GCSE Biology > PAPER 2 > Flashcards

Flashcards in PAPER 2 Deck (78)
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1
Q

Describe how the blood in the left side of the heart differs from the blood in the right side of the heart. (2)

A
  • (more) oxygen / oxygenated
  • (less) carbon dioxide
  • high(er) pressure
2
Q

Suggest what is meant by the term intraventricular (1)

A
  • in ventricle
3
Q
A

A - Conjunctiva

B - Lens

C - Cilary Muscle

4
Q

Explain the changes that take place in the pupil and the cilary muscle when a person focuses on a nearby object. (2)

A
  • lens gets fatter
  • ciliary muscle contract
5
Q

Describe one reflex action that occurs in the eye. (2)

A
  • (in bright light)
  • pupil constricts
6
Q

Give a reason for the lens changing in bright light (1)

A
  • Lets less light into the eye
  • Prevents damage
7
Q

Describe how micropropagation (tissue culture) can be used to produce large quantities of identical plants. (6)

A
  • explant
  • small pieces of plant
  • agar jelly
  • nutrient medium
  • sterile
  • growth hormone
  • control moisture
  • clones
  • all year round
8
Q

Explain what is meant by the term genetic modification (GM) and suggest why a farmer might want to grow a GM crop. (3)

A
  • transfer of gene
  • using vectors and plasmids
  • resistant to pests/disease
9
Q

Describe the advantages to the human body of producing memory cells. (2)

A
  • antibody production faster
  • respond to infections
10
Q

Describe how you would carry out an experiment to find out the energy value of a potato crisp. (4)

A
  • weigh crisp
  • burn crisp
  • burnt completely
  • hold (burning crisp) under tube
  • volume of water
  • measure temperature before and after, find temp change
11
Q

Name the enzyme that cuts DNA. (1)

Name the enzyme that joins DNA. (1)

Name a vector. (1)

A
  • Restriction
  • Ligase
  • Plasmid
12
Q

What is meant by the term transgenic? (1)

A
  • allele from different species
13
Q

Describe how the process of nitrification affects the availability of nitrates to plants. (2)

A
  • (nitrifying) bacteria
  • nitrite into nitrate
14
Q

Describe the biological consequences of cigarette smoking on the human lungs. (5)

A
  • emphysema
  • damage to alveoli
  • bronchitis
  • infection;
  • cilia damaged
  • build up of mucus
  • carcinogens
  • tar
15
Q

Suggest the benefits of producing transgenic hearts. (3)

A
  • transplant
  • (more) hearts available
  • less immune response
  • less deaths
16
Q

Explain what is meant by the term gene (2)

A
  • DNA
  • Codes for a protein
17
Q

Explain how temperature is controlled in the fermenter. (2)

A
  • temperature recorder
  • cooling jacket
18
Q

Explain the purpose of the paddles in the fermenter. (2)

A
  • distributing oxygen for respiration
  • distributing nutrientsfor growth
  • distributing heat
19
Q

Other than temperature, name one condition that needs to be controlled in a fermenter and state why it needs to be controlled. (2)

A
  • pH
  • optimum condition for enzymes
20
Q

Describe how the developing embryo is supplied with nutrients. (3)

A
  • placenta
  • from mother’s blood; diffusion / high conc. to low conc
  • large surface area
  • umbilical cord;
21
Q

Explain how the rate of sweating of a person at rest is affected if that person is in hot air. (2)

A
  • more sweat
  • maintain body temperature
22
Q

Explain how the rate of sweating of a person at rest is affected if that person is in air with a high humidity. (2)

A
  • less evaporation
  • sweat can not disperse
  • cannot cool
  • overheating
  • more sweat;
23
Q

Limewater is an indicator that can be used to show an increase in the level of carbon dioxide.

Suggest why it would not be a suitable indicator for use in some investigations. (1)

A
  • Cannot show amount of CO2
24
Q

Describe the changes that would take place in the eye of a pigeon to help it focus on an approaching hawk. (4)

A
  • ciliary muscle contracts
  • suspensory ligaments slacken / relax
  • lens becomes fat(ter) / thick(er) / wider / rounder
25
Q

Describe what happens to protein from pigeon meat when it is in a hawk’s stomach. (3)

A
  • large to small molecules
  • protease enzyme
  • made into amino acids
  • HCl / acid / low pH;
26
Q

What is meant by the term dominant allele? (1)

A
  • Always expressed
27
Q

What is meant by the term codominant alleles? (2)

A
  • expressed
  • heterozygote
28
Q

Suggest how a woman could accurately determine her body temperature. (2)

A
  • thermometer
  • mouth / ear / armpit
29
Q

Explain why only about 10% of the energy in the cereal crop is transferred to organisms that eat the crop. (2)

A
  • respiration
  • not all eaten
  • not all digested;
30
Q

Explain why temperature must be controlled in the fermenter. (2)

A
  • bcoz respiration produces heat
  • enzymes denatured
  • optimum condition
  • maximum growth
  • microorganisms killed
31
Q

What is another name used to describe a fertilised egg? (1)

A
  • Zygote
32
Q

Explain why the rate of decomposition is affected by the pH of the soil. (2)

A
  • enzymes
  • optimum
  • denatured
33
Q

Explain how nitrate ions help plants to grow. (2)

A
  • amino acids
  • protein / DNA
34
Q

Explain how nitrate ions get into the root cells of plants. (3)

A
  • active transport
  • low to high conc against conc. gradient
  • requires energy
  • root hair (cells) have large surface area
35
Q

Suggest two other modifications to burning food experiment and explain how it would improve the accuracy of the result. (4)

A
  • lid for less heat loss
  • stir for more even temperature
  • digital thermometer for precision
36
Q

Suggest why explants are sterilised (2)

A
  • (kill) bacteria / (kill) pathogens
  • prevent disease / prevent infection
  • (less) competition (for minerals);
37
Q

The destruction of habitat can lead to extinction of species. Give three other disadvantages of deforestation. (3)

A
  • eutrophication
  • soil erosion
  • drought
  • (more) CO2 in air / less CO2 removed
  • loss of medicinal plants
38
Q

Describe the biological consequences of pollution of water by sewage. (4)

A
  • (more) bacteria
  • more decomposition / decompose(rs)
  • more respiration
  • (less) oxygen
  • fish die / animals die
  • mineral ions
  • algal bloom
  • eutrophication
39
Q

Sandy soil contains large soil particles with big air spaces between them. Suggest why many plants may find it difficult to grow in sandy soil. (2)

A
  • less water
  • (less) anchorage
40
Q

What is meant by the term homozygous? (1)

A

same alleles

41
Q

Describe what is meant by the term excretion. (2)

A
  • removal
  • of waste products of cells
42
Q

Explain the role of structure A. (3)

A
  • release sweat / sweating
  • evaporation
  • cooling / heat loss
43
Q

Explain the role of structure B. (3)

A
  • vasodilation
  • (more) blood to skin
  • cooling
44
Q

Explain the role of insulin in homeostasis. (2)

A
  • lower blood glucose
  • glucose to glycogen
  • stored in liver / muscle
45
Q

Explain the role of ADH in homeostasis. (3)

A
  • control water level
  • adjusts permeability of collecting duct
  • water reabsorption
  • more concentrated urine / less urine
46
Q

Explain why the milk must be cooled to 46 °C. (2)

A
  • avoid killing Lactobacillus
  • optimum temperature
  • (enzymes) denatured / destroyed;
47
Q

Explain why the yoghurt is kept in a warm place for 8 hours. (2)

A
  • (time) to make lactic acid
  • (warm) optimum temperature
  • for enzymes
  • bacteria reproduction
48
Q

Changes take place to the pH of the yoghurt when it is kept warm for 8 hours. Describe and explain how the change in pH helps to preserve the yoghurt. (3)

A
  • kills bacteria / stop growth of bacteria
  • low pH / more acid / acidic / lactic acid
  • denatures/destroys enzymes / alters active site
49
Q

State what is meant by the term antibiotic (1)

A
  • removes bacteria
50
Q

Describe how the body’s immune system kills bacteria (4)

A
  • white blood cell
  • phagocyte
  • ingest / engulf / eat
  • digest / breakdown / enzymes
  • lymphocyte
  • antibody / antitoxin
  • antigen
51
Q

Use your knowledge of natural selection to explain why there has been an increase in the number of MRSA bacteria (4)

A
  • variation = some resistant / some not resistant
  • mutation survive(s)
  • reproduces
  • pass on gene(s)
52
Q

Describe how starch is digested in humans. (3)

A
  • salivary gland
  • amylase / maltase (ONCE)
  • pancreas / small intestine
  • maltose / glucose;
53
Q

Suggest why oxygen gas is passed into the calorimeter. (1)

A
  • Increase combustion
54
Q

explain what red blood cells would look like in distilled water (2)

A
  • cells burst
  • water enters cells
  • no cell wall
55
Q

explain what the red blood cells would look like in concentrated sugar solution (2)

A
  • flaccid
  • water leaves cells
56
Q

Suggest why it is important to introduce air into the fermenter. (2)

A
  • oxygen
  • aerobic respiration
  • mix
57
Q

Before being used the empty fermenter is cleaned using steam. Suggest why. (2)

A
  • sterilise / kills microorganisms
  • condenses
  • prevent competition from unwanted organisms
  • prevent chemical contamination of product;
58
Q

Suggest why the bees collect nectar (2)

A
  • to make honey
  • sugar / glucose
  • energy / respiration
59
Q

Name two different groups of organisms that act as decomposers. (2)

A
  • fungi
  • bacteria
60
Q

Describe the changes that take place in the iris when moving into the dark room and explain how they help you to see more clearly. (3)

A
  • radial muscles contract
  • pupil dilates
  • more light can enter;
61
Q

Give two nutrients that should be added to the agar medium. Explain how each nutrient helps plant growth. (2)

A
  • nitrate for amino acids
  • magnesium for chlorophyll
62
Q

Suggest how damage to the air sacs can cause the symptom of breathlessness when exercising (2)

A
  • less surface area;
  • diffusion / gas exchange;
  • (insufficient) oxygen
63
Q

Explain how the vaccination against Pneumococcus provides protection from further infection (2)

A
  • memory cells;
  • antibodies
  • (production and response) sooner
64
Q

Explain how the student could tell whether the seeds had germinated. (2)

A
  • seeds split
  • root
  • shoot
65
Q

Explain how a vaccination will protect a human from having an infection. (3)

A
  • inactive pathogen
  • memory cells
  • antibody;
  • soon(er)
66
Q

Explain how a vaccination will protect a human from having an infection. (3)

A
  • antigen
  • memory cells
  • antibody production
  • soon(er)
67
Q

Suggest why the rate of sweating changes when a person does exercise, such as running. (4)

A
  • muscles;
  • respiration;
  • thermal energy produced
  • evaporation;
  • body temperature falls
68
Q

Describe how you could use an indicator to show how the exchange of carbon dioxide by a leaf changes in the dark and in the light. (2)

A
  • hydrogen-carbonate (indicator)
  • yellow more CO2 / dark
  • purple less CO2 / light
69
Q

Explain why reducing the transport of oxygen to heart muscle cells will make them contract less efficiently and may kill these cells (4)

A
  • less (aerobic) respiration;
  • less energy / ATP;
  • anaerobic respiration;
  • lactic acid;
  • low pH / acidic;
  • denature enzymes;
70
Q

Explain how a mammal such as Dolly the sheep has been cloned. (5)

A
  • nucleus (from body cell) put into enucleated egg;
  • electricity;
  • mitosis / cell division;
  • embryo;
  • uterus / womb;
  • surrogate mother;
71
Q

Name one useful product that can be made in this fermenter. (1)

A
  • Inulin
72
Q

Explain why hamsters need to maintain a constant body temperature. (2)

A
  • optimum temperature for enzymes;
73
Q

Explain what will happen to the muscle cells in the leg if cholesterol builds up in this artery. (5)

A
  • (less) supply of glucose / oxygen;
  • (less) aerobic respiration;
  • (more) anaerobic respiration;
  • less energy / ATP;
  • lactic acid / low(er) pH;
  • enzymes denature;
  • (muscle) cells die / cannot contract;
74
Q

Explain three conditions needed for seeds to germinate. (6)

A
  • oxygen, respiration
  • water to (activate) enzymes
  • optimum temperature for enzymes
75
Q

Describe the role of the placenta in the development of the embryo. (4)

A
  • diffusion;
  • glucose / oxygen;
  • respiration / energy / ATP;
  • amino acids;
  • protein synthesis;
  • vitamins
  • remove carbon dioxide / remove urea;
76
Q

Where in the eye are the cells that detect the change in the stimulus to cause this response? (1)

A
  • Retina / fovea
77
Q

Explain the changes that take place in the pupil as a person moves from bright light into a dark room. (3)

A
  • radial muscles contract;
  • circular muscles relax;
  • pupil gets bigger / wider / dilates / expands
  • more light enters eye;
78
Q

Describe the role of the air supply in a fermenter (2)

A
  • Oxygen
  • Aerobic resp