B4-B6 Paper

Question 1

There are different levels of organism within an ecosystem.

What is the correct order of these levels?

Answer 1

Individual, population, community, ecosystem

Question 2

Bushy lichens are usually more sensitive to pollution than crusty lichens.
Suggest why.

Answer 2

Bushy lichens have a larger surface area to take up pollutants.

Question 3

Explain how a change in an allele can stop a protein functioning correctly.

Answer 3

change in base sequence of DNA
change in order of amino acids
protein shape changes
The shape is not suitable for function e.g. change in enzymes active site shape

Question 4

Changes to population of mice, bacteria and insects can happen over fairly short time periods.
Explain why changes to species such as humans take much longer.

Answer 4

humans reproduce more slowly and go through less generations in a certain time

Question 5

Explain the difference between antibodies and antigens

Answer 5

Antibodies are protein molecules produced by the body to attack pathogens.
Antigen are marker molecules on the surface of the cells that allow the body to identify foreign cells

Question 6

Explain the difference between antibiotics and antiseptics

Answer 6

Antibiotics are internal and kill pathogen

Antiseptics are external to kill pathogen

Question 7

Explain the difference between an allele and a gene

Answer 7

Gene is a section of DNA that code for a protein. Allele is a version of a gene.

Question 8

Explain how scientists could use cells from two species of geese to show that they are closely related.

Answer 8

Extract DNA from both and compare base sequence.

Question 9

Describe how fungal infections can spread and how they enter plant leaves.

Answer 9

Wind or direct contact.

Fungus enters leaves through stomata.

Question 10

Describe how antibodies are usually made in the human body.

Answer 10

Made by white blood cells/lymphocytes

It is stimulated by antigens.

Question 11

Explain what is meant by the term dominant allele.

Answer 11

Version of a gene that always expresses itself when present.

Question 12

What do platelets do?

Answer 12

Platelets are needed for blood clotting.

Question 13

What are the 3 precautions that should be taken when deciding how to mark an organism.

Answer 13

They should not mark brightly otherwise harm to predators.
Should not be poisonous or cause harm
Marks should not be removable

Question 14

Describe how galls form and cause damage to the plant.

Answer 14

Bacteria enters the wound. 
Excess growth chemicals are produced 
Galls grown round root and crown. 
The flow of sap is cut off
Growth is stunted.

Question 15

Why do antibodies not work against other drugs?

Answer 15

Antibodies are specific, only binds to one antigen.