In which organism did Gregor J. Mendel conduct the experiment to explain principles of inheritance ?
- A.Groundnut
- B.Garden Pea
- C.Four O'clock plant
- D.Fruit fly
Correct answer
Explanation
The correct answer is B, Garden Pea. Mendel worked out the laws of inheritance by crossing garden pea plants, Pisum sativum.
Gregor Johann Mendel, an Austrian monk, carried out his hybridisation experiments between 1856 and 1863 in the monastery garden at Brno and published the results in 1866. The pea suited him well: it grows quickly, normally self-pollinates but can be cross-pollinated by hand, and shows seven pairs of clearly contrasting traits such as tall and dwarf stems or round and wrinkled seeds. From these crosses he framed the law of dominance, the law of segregation and the law of independent assortment, which is why he is called the Father of Genetics.
Option A is wrong because groundnut was never Mendel's experimental plant. Option C is wrong because the four o'clock plant (Mirabilis jalapa) is the classic example of incomplete dominance, studied by Correns. Option D is wrong because the fruit fly was used by Thomas Hunt Morgan for his work on linkage and sex-linked genes.
Exam tip: Mendel = garden pea, 7 traits; Morgan = fruit fly; Correns = four o'clock plant.
Practice Questions
View allSyngamy results in formation of
- A.haploid zygote
- B.diploid zygote
- C.non-motile male gametes
- D.motile male gametes
Show answer
Syngamy is the fusion of a male and a female gamete, and since each gamete is haploid, their union gives a diploid zygote.
Read the full explanation →Human insulin molecule is composed of one α-chain having 21 amino acids and one β-chain having 30 amino acids. How many functional insulin genes occur in adult humans?
- A.One
- B.Two
- C.Three
- D.Four
Show answer
Humans have a single functional insulin gene, INS, on the short arm of chromosome 11, and both chains of insulin come from it.
Read the full explanation →Which one of the following is the value of one nanometer?
- A.10⁻⁷ cm
- B.10⁻⁶ cm
- C.10⁻⁴ cm
- D.10⁻³ cm
Show answer
One nanometre is 10⁻⁹ metre, and since one metre is 100 (10²) centimetres, it equals 10⁻⁷ centimetre. The prefix nano means one billionth.
Read the full explanation →Which of the following is the general formula for saturated hydrocarbons?
- A.CₙH₂ₙ₊₂
- B.CₙH₂ₙ₋₂
- C.CₙH₂ₙ₊₁
- D.CₙH₂ₙ₋₁
Show answer
Saturated open-chain hydrocarbons are the alkanes, and every alkane fits the formula CₙH₂ₙ₊₂. In a saturated hydrocarbon every carbon atom is joined to others only by single bonds, so each carbon holds the largest possible number of hydrogen atoms.
Read the full explanation →Which one of the following is not an epidemic disease?
- A.Cholera
- B.Malaria
- C.Smallpox
- D.Elephantiasis
Show answer
Elephantiasis, or lymphatic filariasis, is an endemic disease: it stays steadily present in certain regions and develops slowly over years, rather than breaking out suddenly in a large number of people.
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