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प्रश्न
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.
उत्तर
- The free ear lobe is dominant because it is found in a large majority of the population.
- No. It is not sex-linked. As per the data of the family as well as the class, it is indicated that the free ear lobe is present in males as well as in females.
- Father - Ff (free ear lobe), Mother - Ff (free ear lobe), Rahul - ff (attached ear lobe) and Nisha - Ff (free ear lobe)
OR
Suresh’s father - ff (attached ear lobe), mother - ff (attached ear lobe), Suresh - ff (attached ear lobe), Siya - ff (attached ear lobe). If both parents have recessive characters, then all the children can have recessive characters only.
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संबंधित प्रश्न
Name the scientist who gave the laws of inheritance.
What will you get in the F1 and F2 generations in the following cross?
Pure tall pea plant × Pure dwarf pea plant
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 trait in an organism is influenced by ______
A red-haired woman marries a brown-haired man, and all the children are brown haired. Explain this genetically.
The farmers have been cultivating a food plant X for over two thousand years and have produced as many as five entirely different looking vegetables A, B, C, D and E from it.
(a) What could the plant X be?
(b) What are A, B, C, D and E?
(c) What is the process of evolution involved in this example known as?
Explain Mendel’s law of independent inheritance. Give one example.
Mendel, in one of his experiments with pea plants, crossed a variety of pea plant having round seeds with one having wrinkled seeds. State Mendel’s observations giving reasons of F1 and F2 progeny of this cross. Also, list any two contrasting characters, other than round seeds of pea plants that Mendel used in his experiments.
Hereditary characters are transferred from parents to offspring by ______ hence they are said to be structural and functional units of heredity.
Answer the following question.
Name the plant Mendel used for his experiment. What type of progeny was obtained by Mendel in F1 and F2 generations when he crossed the tall and short plants? Write the ratio he obtained in F2 generation plants.
