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प्रश्न
Define Heredity. Give two examples.
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उत्तर
- Heredity is the transmission of physical or mental traits from parents to offsprings.
- Example: Attached ear-lobes, Rolling tongue.
संबंधित प्रश्न
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.
Mendel crossed tall pea plants with dwarf pea plants in his experiment. Write his observations giving reason on the F1 and F2 generations.
List any two contrasting characters other than roundness of pea plants that Mendel used in his experiments with pea plants.
What constitutes the link between one generation and the next?
Using height (tallness/dwarfness) of a plant as an example, show that genes control the characteristics or traits in an organism.
It it an example of monohybrid cross or dihybrid cross?
What is the genotype of tall plants which always produced tall offspring
What is the genotype of dwarf plants whose parental cross always produces tall offspring?
What sizes of plants are produced if both parents have genes Tt?
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.
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 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?
Who is the pioneer of modern genetics?
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
In the following figure showing a germinating gram seed, name the parts labelled as A, B and C:
Why is Part 'B' considered to be important during germination?
Figures (a) to (d) given below represent the type of ear lobes present in a family consisting of 2 children - Rahul, Nisha and their parents.
|
(a) Rahul's Father |
(b) Rahul |
(c) Rahul's Mother |
(d) Rahul's sister Nisha |
|
(e) |
(f) |
||
| Types of ear lobes | |||
Excited by his observation of different types of ear lobes present in his family, Rahul conducted a survey of the type of ear lobes found {Figure (e) and (f)} in his classmates. He found two types of ear lobes in his classmates as per the frequency given below:
| Sex | Free | Attached |
| Male | 36 | 14 |
| Female | 31 | 19 |
On the basis of the above data answer the following questions.
- Which of the two characteristics - ‘free ear lobe’ or ‘attached ear lobe’ appears to be dominant in this case? Why?
- Is the inheritance of the free ear lobe linked with the sex of the individual? Give a reason for your answer.
- What type of ear lobe is present in father, mother, Rahul and his sister Nisha? Write the genetic constitution of each of these family members which explains the inheritance of this character in this family.
(Gene for the Free ear lobe is represented by F and the gene for the attached ear lobe is represented by f for writing the genetic constitution).
OR
Suresh’s parents have attached ear lobes. What type of ear lobe can be seen in Suresh and his sister Siya? Explain by giving the genetic composition of all.
Mendel crossed pea plants with two pairs of contrasting characters.
| RRYY | × |
rryy |
| Round, Yellow | Wrinkled, Green |
He observed 4 types of combinations in F2 generation. Which of the combinations were new? Write the conclusion drawn by this experiment.
Rewrite the correct form of the statement by changing the first or last word only:
The inheritable feature of an organism is termed as heredity.
