Section II

Questions 1 - 6

Question 1
Cystic fibrosis is a genetic disorder, caused by a recessive allele. The diagram shows the pedigree of a family in which there is a history of cystic fibrosis.

What is the probability of P, Q and R being carriers of the recessive allele for cystic fibrosis?

Question 2
The following equation represents the complete oxidation of glucose to form carbon dioxide and water.

C₆H₆O₆ + x O₂ ---> y CO₂ + z H₂0

What values of x, y and z are required to balance this equation?

Question 3
A cylinder (pictured below) weighs 250N. If the cylinder is stood on its circular face what pressure will it exert on the ground?

A 25000 / π Pa
B 2500 / π Pa
C 25 / π Pa
D 100 / π Pa

Question 4
Use the following words listed below (labelled A to F) to complete the passage. Each word may be used once, more than once or not at all.

A velocity
B constant
C accelerate
D gravity
E decrease
F increase

When a parachutist jumps from a plane he will begin to (---1---) towards the ground. This is a result of (----2----) acting upon him and as such his (----3----) will begin to increase. However as he falls air resistance causes his acceleration to begin to (----4----) until eventually he will reach a (----5----) velocity. At some point he will open his parachute and this will cause air resistance to (----6----) and his velocity to (----7----).

Question 5
An atom of iron has a mass of approximately 9 x10^-23g.

What would the mass be of 3 million iron atoms, measured in kg?

A 2.7 x 10^-19
B 2.7 x 10^-16
C 2.7 x 10^-13
D 2.7 x 10^-10

Question 6
The graph shows changes in the volume of the lungs during breathing movements.

What is happening at point X?

A diaphragm contracting, external intercostal muscles contracting
B diaphragm contracting, external intercostal muscles relaxing
C diaphragm relaxing, external intercostal muscles contracting
D diaphragm relaxing, external intercostal muscles relaxing

Answers for questions 1-6