What is the correct term for the removal from organisms of toxic waste materials of metabolism?
Excretion
15
An ant is 6 mm long. A drawing of the ant is 12 mm long. What is the magnification of the drawing?
x2
15
Which substance is found in plant cell walls?
Cellulose
15
Which structure controls the movement of substances into and out of a cell?
Cell membrane
15
What is a green pigment that absorbs energy from sunlight for photosynthesis?
Chlorophyll
15
What is the term for water diffusing down its concentration gradient?
Osmosis
15
Some plant cells were placed in a concentrated sugar solution. Their cytoplasm and cell membranes shrank and pulled away from the cell walls. What is the term for this condition?
Plasmolysis
15
When animal cells are placed in pure water, they burst. Plant cells do not burst in these conditions. Why don’t the plant cells burst?
The cell wall stops the cell from expanding too much
15
Which nutrients can provide the body with energy?
protein, carbohydrates and fats
15
What is the name of the smaller molecules that join together in long chains to form protein molecules?
amino acids
15
Which nutrient (other than protein) helps to make haemoglobin, which transports oxygen in the blood?
iron
15
What are the 4 smaller molecules from which a fat molecule is made?
3 fatty acids and 1 glycerol
15
In what form is carbohydrate transported in human blood?
glucose
15
Some catalase was added to some hydrogen peroxide. Bubbles of oxygen were given off. After a while, the reaction stopped. Why did the reaction stop?
All the hydrogen peroxide was used up
15
Why does the rate of an enzyme-catalysed reaction increase as temperature is raised from 0 to 40 °C?
The enzymes and the substrates have more kinetic energy so they collide more frequently