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प्रश्न
A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as:
विकल्प
TTWW
TTww
TtWW
TtWw
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उत्तर
TtWW
Explanation:
It's possible that TtWW is caused by the parent's genes. Half of the offspring are short, which means that the parent plant will also have some short genes. All of the offspring had violet flowers, which is more evidence that violet is more common than white.
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संबंधित प्रश्न
How do Mendel’s experiments show that the traits may be dominant or recessive?
"A trait may be inherited, but may not be expressed." Justify this statement with the help of a suitable example.
In one of his experiments with pea plants, Mendel observed that when a pure tall pea plant is crossed with a pure dwarf pea plant in the first generation, F1, only tall plants appear.
(a) What happens to the traits of the dwarf plants in this case?
(b) When the F1-generation plants were self-fertilised, he observed that in the plants of the second generation, F2, both tall plants and dwarf plants were present. Why it happened? Explain briefly.
A pea plant with blue colour flower denoted by BB is cross-bred with a pea plant with white flower denoted by ww.
(a) What is the expected colour of the flowers in their F1 progeny?
(b) What will be the percentage of plants bearing white flower in F2 generation, when the flowers of F1 plants were selfed?
(c) State the expected ratio of the genotype BB and Bw in the F2 progeny.
Define heredity.
Name the information source for making proteins in the cells.
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
With the help of two suitable examples, explain why certain experiences and traits earned by people during their lifetime are not passed on to their next generations. When can such traits be passed on?
The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a person if he inherits a gene for red hair from his mother and a gene for black hair from his father?
Using height (tallness/dwarfness) of a plant as an example, show that genes control the characteristics or traits in an organism.
Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive :
Round seed
In order to ensure that he had pure-breeding plants for his experiments, Mendel :
(a) cross-fertilised each variety with each other
(b) let each variety self fertilise for several generations
(c) removed the female parts of the plants
(d) removed the male parts of the plants.
A pregnant woman has an equal chance of her baby being blood group A or blood group AB. Which one of the following shows the possible genotypes of the woman and the father of her child?
(a) IA IA and IB IO
(b) IA IB and IB IO
(c) IA IO and IB IO
(d) IA IB and IA IO
In humans, if gene B gives brown eyes and gene b gives blue eyes. What will be the colour of eyes of the persons having the following combination of genes?
(a) Bb
(b) bb
(c) BB
Pure-bred round-yellow pea seeds have genotype RRYY and the pure-bred wrinkled-green pea seeds have genotype rryy. Keeping this in mind, write the phenotypes of the following genotypes of hybrid pea seeds :
(a) Rryy
(b) rrYy
(c) rrYY
(d) RrYy
(e) RRyy
List two differences in tabular form between dominant trait and recessive traits. What percentage/proportion of the plants in the F2 generation/progeny were round, in Mendel's cross between round and wrinkled pea plants?
What is genetics?
What will be the number of chromosomes present in each gamete produced by the plants if the palisade cells of a species of the plant contain 28 chromosomes in all?
Assertion: When pure breed tall plants are crossed with pure breed short plants, all the plants in F1 progeny are tall. When the tall plants of F1 progeny are crossed, short plants re-appear in F2 progeny.
Reason: Traits are independently inherited.
Two pink coloured flowers on crossing resulted in 1 red, 2 pink and 1 white flower progeny. The nature of the cross will be
