Mixed Exam Style Questions

Question 1

Which valves is pushed open by oxygenated blood entering a ventricle?

Answer 1

Bicuspid Valve - two openings

Question 2

What type of disease is malaria?

Answer 2

Parasitic

Question 3

Explain discontinuous and continuous varation

Answer 3

Discontinuous variation is usually represented by bar graph. It is controlled by one or two genes and unaffected by the environment.
e.g. blood type

Continuos Variation is usually is represented with a histogram or a curve. It is controlled by a number of genes (polygenes) and are often influenced by environmental factors.
e.g. height

Question 4

What piece of apparatus is used to determine the blood glucose concentration over a short time period following a meal

Answer 4

Biosensor

Question 5

Why is it important to calibrate a colorimeter?

Answer 5

For accuracy and comparable data

Question 6

What is the covalent chemical bond which links two cysteine amino acids

Answer 6

Disulfide

Question 7

Name the molecule that is found in the cell walls of bacterial cells

Answer 7

Peptidoglycan

Question 8

Describe what is happening when the ‘‘lub’ sound is heart?

Answer 8

Atrio Ventricular valves closing and blood leaving the ventricles

Question 9

Describe what is happening when the ‘‘dub’ sound is heart?

Answer 9

The back flow of blood closes the semilunar valves in the aorta and pulmonary artery as the ventricles relax

Question 10

Sucrose is a disaccharide.

What type of reaction occurs when broken down and what monosaccharides are produced?

Answer 10

Reaction - hydrolysis

Monosaccharide - alpha glucose + fructose

Question 11

Sucrase is the enzyme that breaks down sucrose

Which of the bonds is broken by sucrase

Answer 11

Alpha glycosidic

Question 12

The enzyme microtubule depolymerise is responsible for the breakdown of spindle fibres in mitosis.
Which phase has the highest number of active microtubule depolymerise enzyme?

Answer 12

Telophase

Question 13

What test should become positive when amylase is tested?

Answer 13

Benedicts test
Biuret Test

An amylase is an enzyme that catalyses the hydrolysis of starch into sugars.

Question 14

State two differences between a molecule of ADP and DNA nucleotide that contains adenine

Answer 14

ADP has two phosphate groups whereas DNA only has one phosphate group
ADP has a ribose sugar whereas DNA has a deoxyribose sugar

Question 15

ADP binds with an inorganic phosphate to make ATP

Name this type of reaction

Answer 15

Condensation

Question 16

Explain how the genetic code in the gene for tubulin codes for the protein tubulin

Answer 16

Each gene contains a codon which have 3 bases, which code for an amino acid.
The sequences of bases determines the sequence of amino acid and codes for the protein

Question 17

Describe three cellular functions of the cytoskeleton apart from the formation of microtubules

Answer 17

Cytoskeleton provides shape and stability to the cell
Cytoskeleton helps with movement of organelles around the cell e.g. vesicles
Cytoskeleton provides mechanical strength to cells

Question 18

Suggest two ways tubulin is essential to protein synthesis and protein secretion in eukaryotic cells.

Answer 18

Tubulin helps with the movement of mRNA from the nucleus to the ribosome on the rough endoplasmic reticulum

Tubulin helps with the movement of vesicles from the RER to the Golgi where the protein is check and repackaged

Question 19

Explain how to measure the diameter of the nucleus of one of the WBC, when observing the cells through a light microscope

Answer 19

You will need a eyepiece graticule
Calculate for one eye piece unit
Then view the nucleus and find out the diameter in epu
Take repeat measurements and calculate a mean diameter
Use calibrated epu to calculate diameter of nucleus

Question 20

Compare 3 microscopes:

1. SEM
2. TEM
3. Laser Scanning

Answer 20

SEM - 3-10nm, 3D, black and white
TEM - 0.5nm, 2D, black and white
Laser Scanning - 200nm, 2D/3D, colour

Question 21

DNA can be extracted from white blood cells

Explain why the cells do not need to be crushed before adding detergent

Answer 21

Do not have cell walls to break open

Question 22

Suggest the type of enzyme that should be used to extract DNA from White blood cells

Answer 22

Hydrolytic enzyme as it breaks down histones

Question 23

Explain why using standard deviation would increase the confidence in any conclusion made

Answer 23

Standard deviation shows the spread of data around the mean. It reduces the effect of an anomaly

Question 24

Staphylococcus aureus is a bacterium
The graph shows the percentage of samples that were methicillin resistant (MRSA).
Suggest explanations for the positive correlation in the data in the graph

Answer 24

Over prescription of methicillin
Not completing the course
Natural Selection of MRSA

Question 25

Staphlyococcus aureus is the binomial name for a species of bacterium State one advantage of referring to staphylococcus aureus in this way

Answer 25

Universal Language

Question 26

Explain the importance of maintaining biodiversity for the discover of new antibiotics

Answer 26

Plants are used to make drugs | It increases the chance of finding new drugs

Question 27

Explain what is meant by personalised medicine and synthetic biology

Answer 27

Personalised medicine is medicine made catered to someones geneotype/gene Synthetic Biology - is the synthesis of new genes

Question 28

Explain how the structure of glycogen differs from that of amylopectin to make it better suited as an energy store in animals

Answer 28

Glycogen is more branched More coiled More compact so less space needed for storage

Question 29

Describe the structure of alpha glucose and beta glucose

Answer 29

Alpha glucose has OH at the bottom on carbon 1 Beta glucose has OH at the top on carbon 1

Question 30

State two differences between the closed circulatory system of the sea bass and the closed circulatory system of a mammal

Answer 30

Sea bass is single whereas mammal is double | Sea bass blood only goes through heart once, mammal blood goes through heart twice

Question 31

Define the term closed circulatory system

Answer 31

Blood is moving within the vessels

Question 32

Name two arteries that can be seen in a heart

Answer 32

Coronary artery | Pulmonary Artery

Question 33

What is the inner dividing of the wall in the heart called and what does it do?

Answer 33

Septum | Separates oxygenated and deoxygenated blood

Question 34

What is an extracellular enzyme

Answer 34

Works outside of the cell

Question 35

Explain one advantage and one disadvantage of the lack of nuclei and other membrane bound organelles to mammalian erythrocytes

Answer 35

Advantage - large surface area so more uptake of oxygen | Disadvantage - no genetic material so cannot divide

Question 36

Viruses do not use erythrocytes as host cells whereas the malarial pathogen Plasmodium spends part of its life cycle inside erythrocytes Suggest Why

Answer 36

Virus is unable to replicate outside a host cell as it does not contain ribosomes for protein synthesis. Plasmodium uses erythrocytes as host cells to hide from the immune system

Question 37

Explain why erythrocytes do not make use of any of the oxygen that are transporting

Answer 37

They lack mitochondria therefore no aerobic respiration

Question 38

What name is given to a change in the oxygen dissociation curve due to increasing carbon dioxide concentration

Answer 38

Bohr Shift

Question 39

With reference to the structure of blood vessels explain why oxygen is not released until the blood reaches the capillaries

Answer 39

Arteries have thick walls whereas capillaries have think walls. Diffusion distance is shorter in capillaries

Question 40

Explain why the blood off loads more oxygen to actively respiring tissues than to resting tissues

Answer 40

In actively respiring tissue more CO2 is produced CO2 results in dissociation of carbonic acid / increase of H+ , leading to the release of oxygen

Question 41

Which ion: is a cofactor for amylase Prosthetic group for carbonic anhydrase

Answer 41

Cl- | Zn 2+

Question 42

Name a primary defence mechanism against pathogens

Answer 42

Blood clotting

Question 43

Describe how a neutrophil looks like

Answer 43

Multi lobed nucleus

Question 44

Describe how the structure of each blood vessel is adapted to its function. (6 marks)

Answer 44

Artery - carries blood away from the heart under high pressure It has a thick elastic layer which enables them to withstand pressure, as well as stretch and recoil. It has collage which maintains shape and provides structural support. Smooth muscle contracts and relaxes to change the size of the lumen. Veins - carries blood back to the heart, moving against gravity Thin elastic band, has valves to prevent back flow, more collagen to give structural support Capillaries - allows substances to be exchanged Walls are one cell thick so short diffusion distance Only large enough to allow red blood cells to travel through

Question 45

How can PBO acts as an enzyme inhibitor

Answer 45

It is non competitive | the PBO binds to the allosteric site causing the active site to change shape and a substrate can no longer fit into it

Question 46

State two features of organisms that belong to the kingdom Protoctista

Answer 46

Eukaryotic cells, Linear DNA

Question 47

Explain how a pitfall trap can be used to set up and used to sample invertebrate biodiversity.

Answer 47

Dig a hole and place a container in the soil Cover to protect from rain Leave overnight Identify number of invertebrates

Question 48

Many birds are found in moorland habitats, they are red listed and is a high level of concern Suggest measures that could be implemented to protect the biodiversity of moorland habitats.

Answer 48

Education Habitat Restoration Captive Breeding Programmes Give area/red listed species a protected status

Question 49

What products are formed The enzyme thromboplastin + prothrombin = The enzyme thrombin + fibrinogen =

Answer 49

Thrombin | Fibrin