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प्रश्न
What are the components of the DNA molecule?
उत्तर
Phosphoric acid, pairs of nitrogenous bases, and deoxyribose sugar are components of DNA molecule.
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संबंधित प्रश्न
How do Mendel’s experiments show that the traits may be dominant or recessive?
How did Mendel interpret his results to show that traits may be dominant or recessive? Describe briefly.
In a monohybrid cross between tall pea plants (TT) and short pea plants (tt), a scientist obtained only tall pea plants (Tt) in the F1 generation. However, on selfing the F1 generation pea plants, he obtained both tall and short plants in F2 generation. On the basis of above observations with other angiosperms also, can the scientist arrive at a law? If yes, explain the law. If not, give justification for your answer.
What is a gene?
Mendel crossed tall pea plants with dwarf pea plants in his experiment. Write his observations giving reason on the F1 and F2 generations.
Outline a project which aims to find the dominant coat colour in dogs.
Name the scientist who gave the laws of inheritance.
Using height (tallness/dwarfness) of a plant as an example, show that genes control the characteristics or traits in an organism.
What will you get in the F1 and F2 generations in the following cross?
Pure tall pea plant × Pure dwarf pea plant
In the F2 generation of a cross, progeny having different traits are produced in the ratio 3 : 1. State whether it is a monohybrid cross or a dihybrid cross? Give one example of such a cross.
Gregor Mendel's first law of genetics states "Of a pair of contrasted characters, only one can be represented in a gamete by its internal 'factor Give the modern name for this 'factor'.
Gregor Mendel's first law of genetics states "Of a pair of contrasted characters, only one can be represented in a gamete by its internal 'factor' State where these factors are found in gametes.
Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive:
Yellow seed
Why did Mendel choose pea plants for conducting his experiments on inheritance?
A cross between two individuals results in a ratio of 9 : 3 : 3 : 1 for four possible phenotypes of progeny. This is an example of a ______
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.
In the human blood grouping, the four basic blood types are type A, type B, type AB, and type O. The blood proteins A and B are :
(a) simple dominant and recessive traits
(b) incomplete dominant traits
(c) codominant traits
(d) sex-linked traits
The visible characteristic in an organism is known as :
(a) prototype
(b) stereotype
(c) phenotype
(d) genotype
Which of the following statement is incorrect?
(a) for every hormone there is a gene
(b) for every protein there is a gene
(c) for production of every enzyme there is a gene
(d) for every type of fat there is a gene
Pure-bred pea plants A are crossed with pure-bred pea plants B. It is found that the plants which look like A do not appear in F1 generation but re-emerge in F2 generation. Which of the plants A and B are : (i) tall, and (ii) dwarf? Give reason for your answer.
Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in F1generation are then cross-bred to produce F2 generation of pea plants.
(a) What do the plants of F1 generation look like?
(b) What is the ratio of tall plants to dwarf plants in F2 generation?
(c) Which type of plants were missing in F1 generation but reappeared in F2 generation?
A red-haired woman marries a brown-haired man, and all the children are brown haired. Explain this genetically.
Mendel first crossed pure-bred pea plants having round-yellow seeds with pure-bred pea plants having wrinkled-green seeds and found that only round-yellow seeds were produced in the F1 generation. When F1generation pea plants having round-yellow seeds were cross-bred by self pollination, then peas having round-yellow seeds, round green seeds, wrinkled-yellow seeds and wrinkled-green seeds were produced. Mendel collected a total of 2160 seeds.
(a) What will be the number of (i) round green seeds (ii) wrinkled green seeds (iii) round yellow seeds, and (iv) wrinkled-yellow seeds?
(b) Which 'ratio' as established by Mendel have you made use of in answering the part (a) above?
The term 'father of genetics' is used for the scientist :
(a) Morgan
(b) Mendel
(c) Darwin
(d) Marie Curie
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?
"It is possible that a trait is inherited but may not be expressed." Give a suitable example to justify this statement.
Explain Mendel’s law of independent inheritance. Give one example.
Hereditary characters are transferred from parents to offspring by ______ hence they are said to be structural and functional units of heredity.
What is genetics?
Who is the pioneer of modern genetics?
____________ refers to the transmission of genetic information from parental generation to next generation.
In the following Question, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
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
In human males all the chromosomes are paired perfectly except one. This/these unpaired chromosome is/are
- large chromosome
- small chromosome
- Y-chromosome
- X-chromosome
