IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Evolution-Inheritance and Variation
Topic :Evolution– Weightage : 21 %
All Questions for Topic : Life Cycles,Natural Selection,Cell division,Mitosis,Meiosis,Reproduction,Biodiversity,Inheritance and variation,DNA and genetics
Question
A gene carries information for a trait which can be passed on from a parent to a child. Having dimples is one example of a trait. Dimples are a result of a dominant allele (D) whereas not having dimples is a result of a recessive allele (d). (1 mark)
The father of a child has dimples (Dd) and the mother does not have dimples. State the genotype of the mother
▶️Answer/Explanation
Ans: According to the information, father has the genotype “Dd” which means he has one dominant allele (D) for dimples and one recessive allele (d) for not having dimples. Since the mother does not have dimples, it means she does not have the dominant allele (D) and must have two recessive alleles (dd). Therefore, the genotype of the mother would be “dd”.
Question (2 mark)
An organism that is able to produce lactase is said to be lactose tolerant. A copy of the dominant allele, \(T\), must be inherited. The recessive allele has the symbol t.
State whether each genotype below is lactose tolerant or not by completing the table.(1 mark)
▶️Answer/Explanation
Ans:
| Genotype | Lactose tolerant |
| TT | Yes |
| Tt | Yes |
| tt | No |
Question (2 mark)
State the meaning of the term phenotype.
▶️Answer/Explanation
Ans:
The (observable) characteristics of an organism (resulting from the expression of genes)