10 questions · Form 5 Biology Bab 10: Inheritance
10 questions · plays in fullscreen
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Which tool is used in genetics to display family relationships and trace the pattern of inheritance of a genetic trait across generations?
Answer: C
A pedigree chart visualizes phenotypic traits across multiple generations in a family history.
2. What is the probability of a couple having a female child in any single pregnancy?
Answer: B
Each pregnancy has a 50% (1 in 2) probability of producing an XX (female) or XY (male) child.
3. What relationship exists between the alleles I^A and I^B in the human ABO blood group system?
Answer: C
Alleles I^A and I^B are codominant because both antigens are fully expressed in an I^A I^B individual.
4. What term is used to describe an individual possessing two identical alleles for a specific trait?
Answer: B
An individual with identical alleles (e.g., TT or tt) is homozygous.
5. A cross between a red flower and a white flower produces all pink flowers. What genetic phenomenon does this demonstrate?
Answer: B
Incomplete dominance occurs when the heterozygous phenotype is an intermediate blend of the two homozygous phenotypes.
6. What is the genotype of a female who is a carrier for red-green color blindness?
Answer: B
A female carrier is heterozygous, carrying one normal dominant allele (X^C) and one mutant recessive allele (X^c).
7. What are the chromosome numbers and sex chromosome composition in a normal human somatic cell of a male?
Answer: B
Human males have 44 autosomes and 2 sex chromosomes (XY), total 46 chromosomes.
8. If a father has haemophilia (X^h Y) and a mother is homozygous normal (X^H X^H), what proportion of their sons will have haemophilia?
Answer: A
Sons inherit their Y chromosome from the father and an X^H chromosome from the homozygous normal mother; hence 0% of sons will be affected.
9. In a monohybrid cross between two heterozygous tall pea plants (Tt x Tt), what is the expected phenotypic ratio of the offspring?
Answer: B
Crossing two heterozygous individuals (Tt x Tt) yields a 3:1 ratio of dominant (Tall) to recessive (Dwarf) phenotypes.
10. If a man with Blood Type O marries a woman who is homozygous for Blood Type A, what will be the blood type of all their children?
Answer: B
Father genotype is ii; mother genotype is IA IA. All children will inherit IA from mother and i from father, giving genotype IA i (Type A).