Life Sciences Problems focuses on “Quantitative Inheritance”.
1. Traits which show continuous variation is referred as ___________
A. Genetic disorders
B. Phenotypic variation
C. Quantitative traits
D. Qualitative traits
Answer: C
Clarification: On quantitative inheritance, the phenotype of an individual depends upon the number of dominant alleles involved. Here, all the genes show additive effects on the gene.
2. QTL is the chromosomal site at which a group of genes affecting quantitative traits located.
A. True
B. False
Answer: A
Clarification: QTL (quantitative trait loci) is the chromosomal site at which a group of genes affecting quantitative traits is located. Example: height, weight etc.
3. Which of the following factor does not contribute to quantitative traits?
A. Polygenes
B. Environmental
C. Genetic
D. Carbohydrate content
Answer: D
Clarification: Quantitative inheritance is more complex inheritance than Mendelian inheritance as these are influenced by polygenes, genetic factors, and environmental factors.
4. Who explained the multifactorial hypothesis?
A. Ronald Fisher
B. Darwin
C. Mendel
D. Nilsson-Ehle
Answer: A
Clarification: Fisher hypothesis states that a particular trait is the result of the combined influence of genetic and environmental factors.
5. Which of the following describes the dissimilarity in the traits due to the variation in genetic factors?
A. Polygenic
B. Heritability
C. Quantitative trait loci
D. Maternal effect
Answer: B
Clarification: Heritability is a concept of variation which arises due to genetic factors. Often, this term also used to show a resemblance of parents to their offsprings.
6. Which of the following describes the inheritance controlled by cytoplasmic genes?
A. Extranuclear inheritance
B. Heritability
C. Environmental factors
D. Complex trait
Answer: A
Clarification: The cytoplasmic inheritance arises due to plasma genes located in cell organelles. The first time evidence for the cytoplasmic inheritance was presented by coherence in Mirabilis jalapa.
7. Which of the following is NOT true for cytoplasmic inheritance?
A. Reciprocal cross is always different
B. Unequal contribution from male and female gametes
C. It follows a Mendelian pattern of inheritance
D. Do not show segregation for traits
Answer: C
Clarification: Plasma gene inheritance or cytoplasmic inheritance does not follow the Mendelian pattern of inheritance thus it comes under Non-Mendelian inheritance.
8. What is a petite mutant?
A. Defective mitochondrial function of yeast
B. Plastid function mutant
C. Dwarfism
D. Maternal effect genes
Answer: A
Clarification: Mutation responsible for the defective mitochondrial function, produce mutant yeast called petite mutant.
9. Which of the following is NOT the type of petite mutant?
A. Nuclear
B. Neutral
C. Suppressive
D. Polygene
Answer: D
Clarification: Petite mutant are of three types, one is a nuclear petite mutant, which has a nuclear gene mutation, second is a neutral petite mutant, which do not have mitochondrial DNA, and the third one is a suppressive petite mutant.
10. Name the effect which shows the determination of character by the genotype of a female parent?
A. Cytoplasmic male sterility
B. Probability
C. Random mating
D. Maternal effect
Answer: D
Clarification: The phenotype of the child would be determined by the genotype of the mother, such phenomenon is known as a maternal effect.
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