Different varieties of the same gene are called
- A.Genotypes
- B.Sib pairs
- C.Alleles
- D.Isomers
Correct answer
Explanation
The correct answer is C, Alleles. An allele is one of the alternative forms of the same gene, found at the same place on a pair of matching chromosomes.
Each person carries two alleles for most genes, one from each parent. In Mendel's pea plants, the gene for height had two alleles: T for tall, which is dominant, and t for dwarf, which is recessive. A plant with TT or Tt is tall, while only tt is dwarf. When both alleles are the same the organism is homozygous, and when they differ it is heterozygous.
A is wrong because a genotype is the full genetic make-up, the pair of alleles an organism carries, such as Tt, not the variety of a gene itself. B is wrong because sib pairs are two brothers or sisters studied together in genetic research. D is wrong because isomers are chemical compounds with the same formula but different structures.
Exam tip: alleles are forms of a gene; genotype is the pair carried (Tt); phenotype is the trait seen (tall).
Practice Questions
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- A.Hydrogen
- B.Sulphur
- C.Phosphorus
- D.Helium
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- A.80 mm of Hg
- B.100 mm of Hg
- C.120 mm of Hg
- D.140 mm of Hg
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- A.Archaeologists
- B.Anthropologists
- C.Palaeontologists
- D.Geologists
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Read the full explanation →Which of the following catalytic systems is used for the reduction of unsaturated hydrocarbon to saturated hydrocarbon?
- A.Copper and H2
- B.Iron and H2
- C.Zinc and H2
- D.Nickel and H2
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- A.Gibberellins
- B.Abscisic acid
- C.Auxins
- D.Thyroxine
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