potential answers

which of these is a correct statement about the fungus, mucor?

A) mucor is a eukaryotic organism with cell walls made of chitin

plant cells contain chloroplasts, cytoplasm and starch. How many of these are also present in a fungus such as mucor?

B) 1

calculate the area of the fungus

6400mm

which of these is the structure labelled x?

bronchiole

state why a lung is described as an organ

it is a group of tissues

explain how contraction of the diaphragm causes air to move into the lungs

When the diaphragm contracts, it flattens, which increases the volume of the thorax. This decreases the pressure of the thorax, so air enters the lungs.

calculate the volume of oxygen used in 30 minutes by a non smoker with a mass of 70kg

73500

explain the effect of cigarette smoking on the rate at which oxygen is used

Smokers use less oxygen during exercise. This is because tar in cigarette smoke damages the walls of the alveoli, which then break down and fuse together again creating irregular air spaces. This reduces the surface area for gas exchange, meaning less oxygen is diffused into the blood.

in which of the labelled structures does protein synthesis occur?

D) ribosome

which of the labelled structures are also found in plant cells?

C) mitochondrion, nucleus and ribosome

calculate the ratio of the volume of a villus cell to the volume of a sperm cell

give your answer in the form n:1

40:1

using the information in the table, comment on the importance of mitochondria to the activities of different cell types

Sperm cells have the least amount of mitochondria in one cell with 75 mitochondria. However, sperm cells have the most amount of mitochondria in 10um of cell. This is because mitochondria release energy, and sperm cells need a lot of energy so they can swim. 

which group contains euglena?

C) protoctists

which structure is the site of respiration?

D) U

which structure contains chromosomes?

D) T

which structure is the cell membrane?

A) P

which labelled structure is found in plant cells but not in animal cells?

C) S

state what is meant by the term organelle

structures inside of cells that carry out distinct functions

explain which two labelled structures allow Euglena to move through water

their tail (R) allows them to swim

their mitochondria (U) releases energy so they can move

which component is a red blood cell?

C) S

which component is a platelet?

A) P

which component is a lymphocyte?

C) R

which mineral ion is found in haemoglobin?

B) iron

describe how the human immune system reacts to an infection

Phagocytes engulf the pathogen by producing an extension of their cytoplasm, which encloses the pathogen in a vacuole. The phagocyte then secretes enzymes into the vacuole to break down the pathogen. Lymphocytes produce antibodies. Pathogens have antigens on their surface, so the antibodies recognise the antigens, stick to them, and attack them. The antibodies produce are specific to that type of antigen so it will only attack that type of pathogen. 

calculate the number of red blood cells in a 2mm sample of blood

1 × 10⁷

comment on the effects that the number of each blood component could have on the person with the blood condition.

There is no difference in platelets, so there will be no difference in the clotting of blood. There are more lymphocytes which produce antigens, and more phagocytes which engulf the pathogen, so they can fight infections more efficiently. 

which substances are excreted by the lungs?

B) carbon dioxide and water

explain the change in volume of air in the lungs from point X to point Y

The volume increases as the diaphragm contracts, increasing the volume of the thorax and decreasing the pressure inside the thorax, so air enters the lungs.