Topic 2: Genes and health - Edexcel A-Level Biology B quiz

Adenine with cytosine, guanine with thymine

Adenine with thymine, cytosine with guanine

Adenine with uracil, cytosine with thymine

Adenine with guanine, cytosine with thymine

Both strands of each daughter molecule are synthesised entirely from scratch

Only half of the bases in each strand are chemically replaced

Each new molecule has one original strand and one new strand

The original parental molecule is broken down and discarded during replication

On mRNA

On the DNA template

On the ribosome

On tRNA

Forms a faulty chloride channel so mucus becomes thick

Transports far more chloride ions out of the cell than normal

Is folded and functions in exactly the same way as the normal protein

Affects the membranes of red blood cells but no other cell type

An autosomal dominant condition

An autosomal recessive condition

A sex-linked dominant condition

A condition caused only by the environment

Raising the activation energy

Increasing the temperature of the cell

Lowering the activation energy

Being used up in the reaction

Is a perfectly rigid, exact match for the substrate from the outset

Is never complementary in shape to the substrate that binds it

Permanently breaks apart after catalysing a single reaction

Changes shape slightly as the substrate binds

Bonds in its tertiary structure break and it denatures

It continues to work faster and faster without any upper limit

It is converted into a competitive inhibitor of its own reaction

The activation energy of the reaction it catalyses increases

By lowering the temperature of the reaction mixture considerably

By increasing the substrate concentration

By adding a large amount of a non-competitive inhibitor as well

By gently denaturing the enzyme's active site

It changes every single cell throughout the patient's body

It only ever works successfully in fully grown adults

It alters body cells only, not the gametes

It deletes the faulty allele directly from the sperm cells

Two faulty alleles and so shows the full symptoms of the disease

No faulty alleles of the CFTR gene at all

A single faulty allele located only on the Y chromosome

One faulty and one normal allele, and is healthy