Chhattisgarh State Board Class 10 Science Chapter 15 Heredity: From Parents to Offsprings Exercise Multiple Choice, Fill in the Blanks, Questions and Answers here.
Chhattisgarh State Class 10 Science Chapter 15 Solution
1) Choose the right option-
(i) What do you think may have been the reason for Mendel’s success?
(a) Clear planning based on reasoning, experimenting, recording observations etc.and duly writing article regarding the same.
(b) Focusing on certain clear contrasting characters.
(c) Use of mathematical calculations.
(d) All above options.
Ans: – (b).
(ii) Mendel had studied certain contrasting characters of pea plants. Which character doyou think was not chosen by Mendel?
(a) Tall and dwarf plants (b) Yellow and green coloured seeds
(c) Terminal and axial flower (d) Round and wrinkled stem.
Ans: – (d).
(iii) Some people can roll their tongue (roller represented by RR/Rr) and this is an autoso-mal dominant character. Those who can’t roll have the recessive factors (Non rollerrepresented by rr) A child is capable of rolling her tongue. Her brother fails to roll the tongue while twoof her sisters can roll their tongues. If both of the parents can roll their tongue, whatdo you think would be the combination of factors in them?
(a) RR and RR (b) Rr and Rr (c) RR and rr (d) rr and rr.
Ans: – (b) Rr and Rr.
2) Let us consider 4 major blood groups of humans A, B, AB andO. These had been named on the basis of certain antigenic factors.. The presence of both A and B factors represented AB bloodtype while absence of both represented O blood type. Let ustake I to represent the substance responsible for the said factor.IO then represents absence of the substance. Now observe thefollowing table and answer the questions given below the table.
| Blood Group | Factors |
| A | I^A I^A , I^AI^O |
| B | I^B I^B , I^B I^O |
| AB | I^A I^B |
| O | I^O I^O |
- Those having blood group A would have how many IA factors?
- Those of blood group O should have how many IO?
- Which factor do you think is recessive. IO, IA or IB?
- ‘A recessive character represents pure parental generation.’ Justify this statement.
- A child of parents having blood group A has O group. What do you think are thefactors that the parents have? What do you think could be the probable blood grouptype of a second child that they have?
Ans: – As we can see that for blood group A will have two IA allele or one IA allele and one I allele.
For those whose blood group o will show two IO alleles.
The IO factor is recessive.
There is no recessive allele technically.The pure form of characteristics is shown in homozygous condition. The dominant cell enhanced it.
In this condition the child will have A type blood although the both A and O blood type gene are present in his or her body. This will transfer to his own children in future.
3) When a blue flowered plant (BB) is crossed with a white flowered plant (bb) what are the combinations possible in offspring generation?
Ans: –
4) A variety of cow named ‘Zeba’ is adapted to survive in hot conditions. Another variety ‘Sahiwal’gives 20,000 litters of milk every year. The variety ‘Angush’ has a well-built body. If we want to acquire maximum milk from a variety of Cow here in Chhattisgarh, which varieties ofcows do you think must be crossed? Give reasons for your answer.
Ans: – The variety of Sahiwal and Angush is capable of living in moderate temperature like places. So, in Chhattisgarh Zeba will not survive so the Sahiwal and Angush variety would be helpful for the milk production in that area.
5) How will our knowledge of heredity help in improving our crop plants to acquire maximumproduction?
Ans: – The process grafting is necessary for the production of the crop plants to acquire maximum production. The ways in grafting are follows that at first a plant wounded then other inserted in it as a result both plants will survive.
6) How can we choose suitable characters to obtain new varieties of plants? (Hint: We had studied about plants of mustard family in Chapter 1, you may site examples of other plants)
Ans: – The ways by which we can choose the suitable characters to obtain the new varieties of plants are the genetic varieties. In which if the genetic varieties are used then the production as well as the quality also be increased like the uses of genetic varieties seed in mustard fields.
7) A farmer sowed seeds of purple flowered pea plants and claimed that all plants in thefollowing generation would have purple flowers. Was he right? Why, why not?
Ans: – No the farmer is wrong as in the following generation the genotype of the pea purple planta would be white. Although there is no white pea plant at present it will appear in future.
8) We have been able to successfully obtain pink flowered Rose plants by crossing white andred coloured Rose plants respectively. Do you think that some characters do intermix? Why?Site some other examples of this type that are related to agriculture.
Ans: – The pink flowers rose are obtained by crossing the white and red colour plants respectively. The pink colour is formed due the incomplete dominance because there is no possibility of the dominance of one allele completely to the other allele. For this reason, we can see pink rose in various places.
9) What would happen if you played the game of coins with just one coin? What is theprobability of getting a head then?
Ans: – The coin has two surface one is head and other is tail so when we flip the coin the possibility of getting head is 50% or½.similarly, the possibility of getting tail is also 50%.
10) Can we develop high yielding variety seeds by hybridization? Can such seeds be developedonly by crossing pure varieties?
Ans: – The high yielding variety of seeds are produced by hybridization or genetic modification. The different variety are merged to the form the new one which is more production efficiency or produce more crop as well as in quantity also.So, by crossing of different variety seed a pure variety can be produced.
11) The sweetness of milk is due to the presence of Lactose (a type of sugar) in it. You may haveheard about people who fail to digest milk and milk products. The factor responsible for theproduction of the enzyme capable of digesting lactose is usually not present in these people.Even if a single factor for formation of the enzyme is present, lactose digesting enzyme isformed. Now answer the following questions on the basis of this information-
12) What would be the combination of factors of a child who fails to digest milk and milk products? What are characters represented by such factors called?
Ans: – The enzymes which can digest the lactose sugar present in milk are not present then this type of human body affected. As the failed to digest the milk product because the digestive enzymes of lactose sugar are absent.
13) What is the combination of factors in the parents of such a child (take a lactose digesting factor as L) who are capable of digesting milk?
Ans: – The factors which can help to digest the milk specially the lactose is present in the bacteria which are present in the colon in the human body. If someone gas its deficiency then it will be a problem for that person.
14) What percent of children of such parents would be able to digest milk?
Ans: – It came from the study that after the child age or the infancy only 35% are be able to digest lactose property and rest of 65 % are felt some problems in digestion.The digestive percentage in child is more.
12) In green gram, the development of two flowers at the axial position is a recessive character, while the development of a single flower at the axial position is a dominant character. If the dominant condition is represented by ‘SS’ and recessive by ‘ss’ then answer the following questions –
- Find out the percentages of pure and hybrid plants obtained in the second generation(F2generation) after crossing pure parental varieties.
- Find out the percentage of each variety of offspring obtained by a cross between Heterozygous Ss and pure ss varieties.
- What would be the percentage of varieties with single axial flowers when a cross between homozygous variety SS and heterozygous variety Ss is conducted?
Show the formation of gametes and combination of factors in each of the questions of this section.
Ans: –
