Yr10 Biology Mock Exam

Question 1

Cells

Answer 1

are the basic building blocks of all living organisms

Question 2

A tissue is a

Answer 2

group of cells with a similar structure and function

Question 3

Plant and animal cells are———— they have…..

Answer 3

eukaryotic
they have a cell membrane, cytoplasm and genetic material (DNA) enclosed in a nucleus

Question 4

a nucleus controls

Answer 4

the activities of the cell

Question 5

cytoplasm, in which

Answer 5

most of the chemical reactions take place

Question 6

a cell membrane, which controls
cell membrane has

Answer 6

the passage of substances into and out of the cell. It also contains receptor molecules.

Question 7

mitochondria, which is where

Answer 7

aerobic respiration takes place

Question 8

ribosomes, which are where

Answer 8

protein synthesis occurs.

Question 9

In addition to the parts found in animal cells, plant cells often have:
which:

Answer 9

chloroplasts, which absorb light (using chlorophyll) to make food by photosynthesis
a permanent vacuole filled with cell sap.
Plant and algal cells also have a cell wall made of cellulose, which strengthens the cell.

Question 10

Bacterial cells are —- and they much —- than —– are and have

Answer 10

prokaryotic and are much smaller than prokaryotic in comparison.
They have cytoplasm and a cell membrane surrounded by a cell wall.
The genetic material is not enclosed by a nucleus. It is a single DNA loop and there may be one or more small rings of DNA plasmids

Question 11

Describe cellular respiration

Answer 11

as an exothermic reaction (transfers energy to the environment) which is continuously occurring in living cells.
The energy transferred supplies all the energy needed for living processes.

Question 12

Respiration in cells can take place

Answer 12

aerobically (using oxygen) or anaerobically (without oxygen) to transfer energy.

Question 13

Aerobic respiration is represented by the equation:
and the chemical equation:

Answer 13

glucose + oxygen → carbon dioxide + water + energy release
Recognise the chemical symbols: C6H12O6, CO2, O2 and H2O

Question 14

As the oxidation of glucose is ———- in———–respiration much less ——-is transferred than in ——– respiration.

Answer 14

incomplete
anaerobic
energy
aerobic

Question 15

Explain what happens to The heart rate, breathing rate and breath volume during exerciseand why this is ?

Answer 15

The heart rate, breathing rate and breath volume increase during exercise to supply the muscles with more oxygenated blood. This enables increased cellular respiration so more energy is transferred to meet the demands of the muscle cells.

Question 16

Explain what happens if insufficient oxygen is supplied, anaerobic respiration?and what can this cause in long periods of exercise?

Answer 16

If insufficient oxygen is supplied, anaerobic respiration takes place in muscles. The incomplete oxidation of glucose causes a build-up of lactic acid and creates an oxygen debt. During long periods of vigorous activity muscles become fatigued and stop contracting efficiently.

Question 17

The heart is an organ that
in a what system

Answer 17

pumps blood around the body in a double circulatory system. (Heart to lungs to heart; heart to rest of body to heart)

Question 18

The natural resting heart rate is controlled by

Answer 18

a group of cells located in the right atrium that act as a pacemaker.

Question 19

Red blood cells contain
which transports it from the — to the —-

Answer 19

contain haemoglobin which binds to oxygen to transport it from the lungs to the tissues.

Question 20

In coronary heart disease layers of
this results in

Answer 20

fatty material build up inside the coronary arteries, narrowing them, reducing the flow of blood and resulting in a lack of oxygen to the heart cells.

Question 21

Stents are used to keep the
Statins are widely used to

Answer 21

the coronary arteries open.

reduce blood cholesterol levels which slow down the rate of fatty material deposit.

Question 22

In the case of heart failure a donor heart, or:
Artificial hearts are occasionally used to:
or to

Answer 22

heart and lungs can be transplanted.

keep patients alive whilst waiting for a heart transplant, or to allow the heart to rest as an aid to recovery

Question 23

Represent photosynthesis with the equation:

Answer 23

light
carbon dioxide + water → glucose + oxygen

Question 24

Describe photosynthesis
which energy is transferred from the environment to the what by what

Answer 24

an endothermic reaction in which energy is transferred from the environment to the chloroplasts by light.

Question 25

Pathogens are
some examples are

Answer 25

microorganisms that cause infectious disease: viruses, bacteria, protists or fungi.

Question 26

Pathogens may infect
and can be spread by:

Answer 26

plants or animals and can be spread by direct contact, water or air.

Question 27

Malaria
what is it?
How do you control/prevent it?

Answer 27

Symptoms of recurrent episodes of fever, which can be fatal. Spread is controlled by preventing the mosquito vectors from breeding and by using mosquito nets to avoid being bitten.

Question 28

Traditionally drugs were extracted from plants and microorganisms for example

Answer 28

The heart drug digitalis originates from foxgloves.
The painkiller aspirin originates from willow.
Penicillin was discovered by Alexander Fleming from the Penicillium mould.

Question 29

Results of testing and trials are published only after
to help prevent:

Answer 29

after scrutiny by peer review to help prevent false claims.

Question 30

Different types of disease may interact:

Answer 30

-Defects in the immune system mean that an individual is more likely to suffer from infectious diseases.
-Viruses living in cells can be the trigger for cancers.
-Immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma.
-Severe physical ill health can lead to depression and other mental illness

Question 31

Describe how monoclonal antibodies are produced

Answer 31

Mouse lymphocytes stimulated to produce a specific antibody.
Lymphocytes combined with a tumour cell to form hybridoma cells.
Hybridoma cells both divide and make the antibody.
Single hybridoma cells are cloned to produce many identical cells that all produce the same specific antibody.
A large amount of the antibody can be collected and purified.

Question 32

Monoclonal antibodies are specific to
they can therefore

Answer 32

one binding site on one protein antigen. They can therefore target a specific chemical or type of cell within the body.

Question 33

Describe uses of monoclonal antibodies:

Answer 33

Diagnosis: in pregnancy tests a monoclonal antibody binds to the hormone hCG produced by the embryo.
In laboratories: monoclonal antibodies are used to measure the levels of hormones and other chemicals in blood, or to detect pathogens.
In research: to locate or identify specific molecules in a cell or tissue by binding to them with a fluorescent dye.
To treat some diseases: for cancer the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing.

Question 34

Three overall stages of the cell cycle:

Answer 34

Interphase: Before a cell can divide it needs to grow and increase the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome.
Mitosis: In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides.
Cytokinesis: Finally the cytoplasm and cell membrane divides to form two identical cells

Question 35

Meristem tissue in plants can :
Uses of stem cells from Meristems in plants:

Answer 35

can differentiate into any type of plant cell, throughout the life of the plant

Produce clones of plants quickly and economically.
Rare species can be cloned to protect from extinction.
Crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers.

Question 36

Sexual reproduction involves the joining (fusion) of male and female gametes
which is what in animal cells and what in plant cells:

Answer 36

• sperm and egg cells in animals
• pollen and egg cells in flowering plants

Question 37

Asexual reproduction involves only one:
There is no mixing of genetic information. This leads :

and so only what happens?

Answer 37

parent and no fusion of gametes.
to genetically identical offspring (clones). Only mitosis is involved

Question 38

In sexual reproduction there is mixing of —– which leads to —–
The formation of—– involves ——-

Answer 38

genetic information which leads to variety in the offspring.

gametes involves meiosis

Question 39

Arteries structure and why and function :

Answer 39

Arteries carry blood away from the heart .
thick elastic walls without valves inside, blood flows under high pressure and carries blood away from the heart to different parts of the body.

Question 40

Veins structure and why and function :

Answer 40

Veins are the blood vessels that carry blood back towards the heart. They have thinner walls, and thinner layers of smooth muscle than arteries, as the blood pressure within them is lower. Veins also contain valves, which are used to prevent the backflow of blood through the lower pressured venous circulation.

Question 41

Capillaries structure and why and function :

Answer 41

The walls of capillaries are just one cell thick. Capillaries therefore allow the exchange of molecules between the blood and the body’s cells - molecules can diffuse. across their walls. This exchange of molecules is not possible across the walls of other types of blood vessel.

Question 42

Muscle cell function and adaptation :

Answer 42

function: contract and relax in order to move the skeleton, blood or substances in the body
adaptations: many mitochondria to provide energy for muscle contraction

Question 43

Root hair cell function and adaptation :

Answer 43

Function: Absorb water and mineral ions from the soil
Adaptations: - long ‘finger like’ villi which gives it a large surface area there is a thin wall to reduce the distance that molecules need to move to reach inside of the cell

Question 44

Sperm cell:

Answer 44

A
Function: this is the male gamete (sex cell) . It carries genetic information from the father and fertilises the egg cell
Adaptations:-many mitochondria to provide energy for movement of the tail
-the head has a specialised sac of enzymes called acrosome that digests the outer lining of the egg cell
-long tail to help propel the sperm along to the nucleus
-nucleus contains half the number of chromosomes of an adult cell

Question 45

Xylem cell
function and adaptations

Answer 45

function: to transport water and mineral ions from the roots of the leaves of a plant and provides support for the plant
adaptations: -consist of dead hollow cells- maximising space for water and dissolved substances to be transported
-walls of the xylem vessels are lignified (coated with lignin) this strengthens the xylem

Question 46

nerve cell
function and adaptions

Answer 46

function; to transmit information(messages) as electrical impulses
adaptations: long- to carry impulses rapidly throughout the body with no gaps between neurones
-insulatory sheath made of fatty myelin- to speed up impulses (100m/s)
-branched endings(dendrites)-make connections with other neurones and allow several different pathways for the impulse

Question 47

Compare the processes of aerobic and anaerobic respiration with regard to the need for oxygen, the differing products and the relative amounts of energy transferred.

Answer 47

Aerobic respiration is respiration using oxygen its the most efficient way to transfer energy from glucose . Aerobic respiration goes on all the time in plants and animals.
Anaerobic respiration is used if there isn’t enough oxygen its an incomplete breakdown of glucose making lactic acid . This causes oxygen debt which is the amount of extra oxygen your body needs to react with the build up of lactic acid and remove it from cells.

Question 48

right ventricle job :

Answer 48

pumps blood to the lungs where gas exchange takes place

Question 49

left ventricle job and adaptations:

Answer 49

thicker wall with more muscle to generate a higher pressure to pump blood a longer distance to the rest of the body

Question 50

Explain the effect of light intensity on the rate of photosynthesis:

Answer 50

Without enough light, a plant cannot photosynthesise very quickly - even if there is plenty of water and carbon dioxide and a suitable temperature. Increasing the light intensity increases the rate of photosynthesis, until some other factor - a limiting factor. - becomes in short supply.

Question 51

Explain the effect of temp on the rate of photosynthesis:

Answer 51

As temperature increases the number of collisions increases, therefore the rate of photosynthesis increases. However, at high temperatures, enzymes are denatured. This can be caused by heat, altered pH or by chemical agents. and this will decrease the rate of photosynthesis.

Question 52

Explain the effect of carbon dioxide on photosynthesis:

Answer 52

Factors affecting photosynthesis - Photosynthesis - OCR …
Carbon dioxide - with water - is one of the reactants in photosynthesis. If the concentration of carbon dioxide is increased, the rate of photosynthesis will therefore increase. Again, at some point, a factor may become limiting.

Question 53

chlorphylls affect on photosynthesis

Answer 53

The amount of chlorophyll also affects the rate of photosynthesis: plants in lighting conditions unfavourable for photosynthesis synthesise more chlorophyll, to absorb the light required.
hlorophyll absorbs the light required to convert carbon dioxide and water into glucose.

Chlorophyll is green - so absorbs the red and blue parts of the electromagnetic spectrum and reflects the green part of the spectrum.

Leaves with more chlorophyll are better able to absorb the light required for photosynthesis.

Question 54

Explain that the process of peer review helps to

Answer 54

detect false claims and to establish a consensus about which claims should be regarded as valid.
Peer-review is where other scientists check results and scientific explanations.

Question 55

Explain that reports of scientific developments in the popular media are

Answer 55

not subject to peer review and may be oversimplified, inaccurate or biased. This means that even though news stories are often based on data that has been peer-reviewed the data might be presented in a way that is over-simplified or inaccurate making it open to misinterpretation

Question 56

How to do an investigation:

Answer 56

-look for any potential hazards
- decide how you will reduce any risk
- write down your plan
- make a risk assessment
- make a prediction and hypothesis
- draw a blank table ready for the results

Question 57

A fair test is one which only the

Answer 57

independent variable is allowed to affect the dependent variable

Question 58

Independent variable

Answer 58

AQA definition: The variable for which the values are changed or selected by the investigator

Question 59

Dependent variable

Answer 59

AQA definition: The variable of which the value is measured for each and every change in the independent variable

Question 60

Control variables

Answer 60

These are the variables that must be kept constant (controlled)
AQA definition: Are the variables that may, in addition to the independent variable, affect the outcome of the investigation and therefore has to be kept constant or at least monitored.

Question 61

General rules for writing methods

Answer 61

Write your method as a set of instructions (not as a description of what you did)
Divide your method up into numbered steps
In each step name the piece of equipment you are using
PRACTISE QUESTIONS