IGCSE Biology Mock

For Mocks

Allele

A version of a gene.

Convert 2000 nm to µm

2 µm

Osmosis

The movement of water from a dilute to a concentrated solution through a partially permeable membrane.

What is the function of the placenta?

Exchange of nutrients

Which hormone controls blood sugar levels?

Insulin

What deficiency disease is caused by lack of vitamin C?

Scurvy

What are the main products of digestion?

Glucose

What is the balanced chemical equation for photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

Which organelle is responsible for aerobic respiration?

Mitochondria

What is the role of iron in the body?

Helps form hemoglobin in red blood cells

Diffusion

The net movement of particles from a high to a low concentration.

What is meant by reproduction?

The process of making more of the same kind of organism.

What is the function of the placenta?

Exchange of nutrients

What is transpiration?

Loss of water vapour from plant leaves through the stomata

What is a food chain?

A sequence showing feeding relationships

How to convert µm to nm

Multiply by 1000

What is urea and how is it produced?

Waste product formed in liver from breakdown of excess amino acids

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

What is natural selection?

Survival and reproduction of organisms best adapted to their environment

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

What is a genotype?

The genetic makeup of an organism

How is glucose reabsorbed in kidneys?

By active transport in the proximal convoluted tubule

Which enzyme breaks down starch?

Amylase

What is a food chain?

A sequence showing feeding relationships

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

What is the test for proteins?

Biuret test – turns from blue to purple

What deficiency disease is caused by lack of vitamin C?

Scurvy

What is active transport?

Movement of particles against a concentration gradient using energy from respiration.

What happens to enzymes at low temperature?

They work more slowly due to lower kinetic energy.

What is the balanced chemical equation for photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2

Mitosis

Cell division that produces two identical daughter cells.

Magnification formula

Image size ÷ Actual size

Which hormone controls blood sugar levels?

Insulin

What is transpiration?

Loss of water vapour from plant leaves through the stomata

What is translocation?

Movement of sugars and amino acids in phloem from sources to sinks

What is a synapse?

A junction between two nerve cells where neurotransmitters transmit the signal

What is a phenotype?

The physical expression of the genotype

What deficiency disease is caused by lack of vitamin C?

Scurvy

What are the bases in DNA?

Adenine

1 centimetre (cm) in millimetres (mm)

10 mm

What is a trophic level?

The position of an organism in a food chain

What is the function of xylem vessels?

Transport water and mineral ions from roots to leaves

What deficiency disease is caused by lack of vitamin C?

Scurvy

What are the bases in DNA?

Adenine

What does 'partially permeable membrane' mean?

A membrane that only allows certain substances to pass through.

What is a phenotype?

The physical expression of the genotype

What is the function of ribosomes?

Protein synthesis

Name one plant response to light.

Phototropism

1 millimetre (mm) in micrometres (µm)

1000 µm

Excretion

The removal of toxic waste substances from the body.

What is a trophic level?

The position of an organism in a food chain

What is transpiration?

Loss of water vapour from plant leaves through the stomata

What colour does hydrogen carbonate turn in low CO2?

Purple

What happens to enzymes at low temperature?

They work more slowly due to lower kinetic energy.

What deficiency disease is caused by lack of vitamin C?

Scurvy

Which process produces more energy: aerobic or anaerobic respiration?

Aerobic respiration

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

Meiosis

Cell division that produces four genetically different gametes.

Why is nitrate important for plants?

For making amino acids and proteins

What is a genotype?

The genetic makeup of an organism

What deficiency disease is caused by lack of vitamin C?

Scurvy

Why do enzymes only work with specific substrates?

Because of the shape of their active site (lock and key model).

What is active transport?

Movement of particles against a concentration gradient using energy from respiration.

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

Which process produces more energy: aerobic or anaerobic respiration?

Aerobic respiration

What is a trophic level?

The position of an organism in a food chain

What is urea and how is it produced?

Waste product formed in liver from breakdown of excess amino acids

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

Why do enzymes only work with specific substrates?

Because of the shape of their active site (lock and key model).

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

What deficiency disease is caused by lack of vitamin C?

Scurvy

What is a food chain?

A sequence showing feeding relationships

What is selective breeding?

Humans choosing organisms with desirable traits to reproduce

Gene

A segment of DNA that codes for a specific protein.

Evolution

The gradual change in species over time through natural selection.

Why is energy lost between trophic levels?

Due to respiration

Respiration

The process of releasing energy from glucose.

What is a food chain?

A sequence showing feeding relationships

What is a dominant allele?

An allele that is always expressed even if only one is present

How to convert mm to nm directly

Multiply by 1

What is the test for proteins?

Biuret test – turns from blue to purple

Why is energy lost between trophic levels?

Due to respiration

What does 'sensitivity' mean in MRS GREN?

The ability to detect or sense changes in the environment and respond to them.

What is active transport?

Movement of particles against a concentration gradient using energy from respiration.

Which enzyme breaks down starch?

Amylase

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

Where does aerobic respiration occur?

Mitochondria

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

What is meant by reproduction?

The process of making more of the same kind of organism.

What is the function of the placenta?

Exchange of nutrients

What is a dominant allele?

An allele that is always expressed even if only one is present

How is the small intestine adapted for absorption?

Villi and microvilli increase surface area; rich blood supply; thin walls

What is anaerobic respiration in humans?

Glucose → Lactic acid (+ small amount of energy)

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

Active Transport

The movement of substances against a concentration gradient using energy.

How is oxygen transported in the blood?

Bound to hemoglobin in red blood cells

What is the role of estrogen?

Repairs uterine lining and stimulates LH release