Two carriers of cystic fibrosis consider embryo screening. Screening can identify embryos with two recessive alleles, but the IVF process may not produce an unaffected embryo suitable for transfer.
Evaluate embryo screening for this couple.
[6 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A transect runs from a shaded wall into a lawn. Mean plant counts per quadrat at 0, 2, 4, 6 and 8 m are 1, 3, 6, 6 and 5 respectively.
.1
Describe the pattern in the data without claiming a cause.
[2 marks]
.2
Explain how to investigate whether light accounts for the pattern.
[2 marks]
4 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
An engineer wants all cells of a new plant to contain an introduced gene. Another proposal would insert the gene into just a few cells of a fully grown leaf.
.1
Explain why introducing the gene at an early developmental stage is more suitable for the first aim.
[2 marks]
.2
Explain a limitation of inserting the gene only into a mature leaf.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Rose leaves develop black spots and fall early. A grower collects fallen leaves, then sprays a fungicide. A neighbour claims that antibiotics would always be a better treatment.
.1
Explain why early leaf loss reduces plant growth.
[2 marks]
.2
Evaluate the treatments described.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A buried bone is found in sedimentary rock, while a soft-bodied organism from the same ancient habitat has left no recognisable fossil.
.1
Describe how the bone could become a fossil.
[2 marks]
.2
Explain why this find cannot prove that only hard-bodied organisms lived there.
