The chimpanzee is a vertebrate.
1. State the main group of vertebrates to which the chimpanzee belongs.
2. State two features, visible in Figure, which suggest that it belongs to this group of vertebrates.
Question 17
17.
The following figure shows a model of how enzymes work.
Enzymes are biological catalysts.
1. Explain what is meant by the term catalyst.
2. State why enzymes are important for organisms.
Question 18
18.
The figure shows a villus from the small intestine of a mammal and an enlarged view of a villus.
1. Explain why villus cells have many microvilli and mitochondria.
Question 19
19.
The following figure shows a section through a teeth.
1. State two functions of a teeth.
2. Describe the importance of teeth in digestion.
Question 20
20.
Eating food contaminated by bacteria can cause illness. This type of illness is called food poisoning.
Food poisoning is caused by different types of bacteria.
A common type of bacterium that causes food poisoning is Campylobacter jejuni.
1. State the genus of this species.
2. Food poisoning can result in vomiting and diarrhoea. Outline the treatment of diarrhoea.
Question 21
21.
A man is overweight.
The figure shows his diet. He consumes 15000kJ a day.
1. Suggest why the diet shown in the figure is not considered to be a balanced diet.
2. Suggest and explain how the man could reduce his weight.
Question 22
22.
The figure below shows the human digestive system.
1. Explain the importance of chemical digestion.
2. Two functions of the alimentary canal are mechanical digestion and chemical digestion. Outline where and how chemical digestion occurs in the alimentary canal.
3. Substances that are absorbed from the alimentary canal may enter cells and become part of the cells.
(i) State the storage carbohydrate made from glucose in liver cells.
(ii) Fat is produced from fatty acids and glycerol by cells in the fatty tissue beneath the skin. State one function of this layer of fat.
A protease is added to a cloudy suspension of protein in a test-tube and kept at 37 °C. After eight minutes, the suspension changes from cloudy to transparent. Which product, or products, will now be present in the test-tube?
amino acids
fatty acids
glycerol
simple sugars
The following can be used to write a word equation for photosynthesis.
carbon dioxide and water
light and chlorophyll
glucose and oxygen
Which shows a correct word equation for photosynthesis?
1→2 in the presence of 3
1→3 in the presence of 2
2→3 in the presence of 1
3→1 in the presence of 2
What is a symptom of scurvy?
bleeding gums
breathelessness
diarrhea
pain in joints
What is an appropriate treatment for severe diarrhoea?
avoiding drinking
avoiding high-fibre foods
drinking a dilute solution of salt and glucose
eating high fat foods
These actions may be important in controlling the spread of disease.
1 washing hands after going to the toilet
2 disposing of waste frequently
3 using separate cutting boards for meat and salad
4 disposing of raw sewage into a river
Which would help control the spread of disease?
1, 2, 3 and 4
1, 2 and 3 only
2 and 3 only
4 only
Which statement describes active transport?
the movement of ions through proteins in a cell membrane, releasing energy
the movement of ions through proteins in a cell membrane, using energy
the movement of water through lipids in a cell membrane, releasing energy
the movement of water through lipids in a cell membrane, using energy
One strand of a DNA molecule contains the base sequence AGT.
What is the base sequence on the other strand of the DNA molecule?
AGT
GAT
TAC
TCA
What is the function of the lacteal in a villus?
absorbs the fatty acids
allows substances to pass from the lumen of the intestine into the villus
takes oxygen to the villus
absorbs the glucose and amino acids
What is the best source of vitamin C in a balanced diet?
fish
fruit
meat
rice
A young, active woman requires more of which constituent in her diet than a young, active man?
fat
iron
protein
vitamin
Which condition could be caused by a lack of iron?
anaemia
cholera
scurvy
diabetes
In which part of the alimentary canal do chemical digestion and mechanical digestion take place?
colon
duodenum
mouth
oesophagus
A lack of which dietary component can result in constipation?
fat
fibre
carbohydrate
protein
A woman requires more calcium in her diet when she is pregnant. Which statement explains why?