2015 – MAY
(IB 2015/MAY – HL P1/33C)
What prevents independent assortment of genes?
A. Genes on separate chromosomes
B. Crossing over between chromosomes
C. Genes close together on the same chromosome
D. Genes located on autosomes
(IB 2015/MAY – HL P1/34B)
Skin colour is a trait controlled by polygenic inheritance. Which statement is correct?
A. Skin colour shows discontinuous variation
B. Individuals show a wide range of phenotypes for skin colour
C. No two people have the same skin colour
D. Children always have the same skin colour as one of their parents
2014 – NOV
(IB 2014/NOV – HL P1/34C)
A cross is performed including two linked genes.
If the genes are far enough apart for crossing over to occur between the genes, which of the offspring would be recombinants?
- AaBb
- Aabb
- aaBb
A. I only
B. I and II only
C. II and III only
D. I, II and III
(IB 2014/NOV – HL P1/35A)
Which phenotypic variation results partly from polygenic inheritance in humans?
A. Skin colour
B. Hemophilia
C. Sex determination
D. Hair length
2014 – MAY
(IB 2014/MAY – HL P1/33B)
When do homologous chromosome pairs separate during meiosis?
A. Prophase I
B. Anaphase I
C. Metaphase II
D. Anaphase II
(IB 2014/MAY – HL P1/34B)
One model for skin colour proposes three separately inherited codominant genes that can affect darkness. Each dark-skin allele (P, Q or R) contributes one equal unit of darkness. The recessive alleles do not contribute to darkness. Which genotype would likely produce the same skin darkness as PpQqRr?
A. PpQQRr
B. ppQqRR
C. PpqqRr
D. PPqqRR
2013 – NOVEMBER – HL
(IB 2013/NOV – HL 1/D)
