May 2022 SL

Question 1

A cell contains chloroplasts, plasma membrane and 80S ribosomes. What type of cell could it be?

Answer 1

Bryophyte

Question 2

More than 90% of cellular cholesterol is located in the cell’s plasma membrane. What is the
main role of cholesterol in the plasma membranes of mammalian cells?

Answer 2

To regulate membrane fluidity

Question 3

What is/are required for facilitated diffusion?
I. A concentration gradient
II. ATP
III. A channel protein

Answer 3

I and III only

Question 4

Which cell component arose first during the formation of the earliest cells?

Answer 4

Plasma membrane

Question 5

In the chimpanzee (Pan troglodytes), the haploid number of chromosomes is 24. How many
sister chromatids are present in the G2 phase of a somatic cell, such as a cell in the bone marrow
of the chimpanzee?

Answer 5

96

Question 6

What are linked by hydrogen bonds?

Answer 6

Hydrogen and oxygen in different water molecules

Question 7

Which reaction occurs when a dipeptide is formed from amino acids?

Answer 7

Condensation

Question 8

What is the reason for the drop in enzyme activity above 40°C?

Answer 8

Changes to the conformation of the enzyme

Question 9

A molecule of DNA is found to contain 200 guanine bases, representing 25% of the total number
of bases. How many phosphate groups does this molecule of DNA contain?

Answer 9

800

Question 10

What is the minimum number of nucleotides needed to code for a polypeptide composed of
210 amino acids?

Answer 10

630

Question 11

Which hypothesis provides the most likely explanation for the curve?

Answer 11

As exercise intensity increases, lactate is converted back to glucose.

Question 12

What is the limiting factor at X?

Answer 12

Temperature

Question 13

What can be deduced from the information in this table?

Answer 13

Humans produce about half as many proteins as rice.

Question 14

Chromosome numbers vary between species. Which statement refers to humans?

Answer 14

An egg cell has two X chromosomes.

Question 15

What is produced by meiosis in a cell of a male animal?

Answer 15

Four gametes, each with the same number of chromosomes

Question 16

Huntington’s disease is an autosomal dominant genetic disease. What are the chances of
two parents that are heterozygous for the gene having a child with Huntington’s disease?

Answer 16

75%

Question 17

What is a community?

Answer 17

A group of populations interacting with each other within a given area

Question 18

Which pyramid of energy represents this information?

Answer 18

Eagles
Snakes
Mice
Seeds

Question 19

Which processes are taking place at X and Y?

Answer 19

respiration combustion

Question 20

Mammals, birds and reptiles have an embryonic tail that may disappear during development.
What is the most likely explanation?

Answer 20

All vertebrates have a common ancestor

Question 21

What can be deduced from this graph?

Answer 21

Bacteria with beneficial adaptations survive and pass on their genes.

Question 22

The plant in the diagram has vascular tissue and reproduces by spores.
To which phylum does the plant belong?

Answer 22

Filicinophyta

Question 23

Which cladogram best represents the relationship between the five species?

Answer 23

A.
Q T S R P

Question 24

Which process describes starch metabolism in humans?

Answer 24

Glucose produced by the digestion of starch can be stored as glycogen.

Question 25

Which structures are part of the walls of both capillaries and veins?
I. Cells
II. Pores
III. Elastic fibres

Answer 25

I only

Question 26

What is a method of transmission of HIV and its effect on the immune system?

Answer 26

Breastfeeding Decrease in number of active lymphocytes

Question 27

A cell from the lungs, observed under the microscope, contains a large number of
secretory organelles. Which conclusion can be drawn about the cell?

Answer 27

It is a type II pneumocyte

Question 28

The image shows a neuron.
What is the function of X?

Answer 28

Increases the speed of transmission along the axon

Question 29

Leptin helps to regulate body mass in humans and mice. The image shows an obese mouse (O)
and a normal mouse (N). Leptin binds to receptors in the hypothalamus of mouse NWhat hypothesis could account for the differences between the mice?

Answer 29

Leptin binds to receptors in the hypothalamus of mouse N

Question 30

What is most likely to increase in the presence of insulin?

Answer 30

The uptake of glucose by muscles