Cambridge IGCSE Biology revision

Which one of these statements about enzymes isn't true.

• The active site on the enzyme has a specfic shape to only fit one substrate.

• When the temperature around the enzyme is above it's optimum temperature, the enzyme will start to denature.

• Enzymes can speed up reactions. Examples can be breaking down molecules, or putting molecules together.

• When a enzyme is in a pH that is not in it's optimum pH range, it will die.

• Denaturing is when the enzyme, and it's active site, change shape.

Which organelles do you find in a plant cell but not an animal cell?

• Cell Membrane

• Vacuole

• Cytoplasm

• Chloroplasts

• Cell Wall

Which two groups of organisms breakdown dead and decaying matter?

• decomposers

• detritivores

• animals

• plants

What are the little air sacs in your lungs called?

• Bronchioles

• The bronchus

• Trachea

• Alveoli

What is the correct order for a reflex?

• receptor --> motor neuron --> relay neuron --> sensory neuron --> effector

• receptor --> sensory neuron --> relay neuron --> motor neuron --> effector

• effector --> sensory neuron --> motor neuron --> relay neuron --> receptor

• receptor --> sensory neuron --> motor neuron --> relay neuron --> effector

What is the function (job) of the white blood cells?

• To transport oxygen around the body.

• To carry dissolved sugars.

• To clot and cover wounds like cuts and grazes.

• To release antibodies to help destroy infections.

What is meant by a prokaryotic cell?

• A cell without a nucleus

• A cell with a nucleus

• A cell without a cell membrane

• A cell with two nuclei.

What happens to the pupil in a bright room?

• dilates - more light in

• constricts - less light in

What is the equation to work out overall magnification from eyepiece magnification and objective lens magnification?

• Overall= Objective x Eyepiece

• Overall= Objective/Eyepiece

• Overall= Eyepiece/Objective

Which phase does sodium enter the cell?

• Depolarization

• Repolarization

• Resting

• Hyperpolarization