Heredity and Evolution: Class 10 Science Q&A · Page 3
47 free answers on Heredity and Evolution (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10CBSE
What are the different ways in which individuals with a particular trait may increase in a population?
Solution: An individual attribute could increase a population in the following 2 ways: (a) Natural selection: If an attribute is useful to a population, it’ll increase naturally. For example, mosquitoes which are resilient against a particular pesticide will pass on their genes so that future generations become resistant as well. The mosquitoes which are affected by the pesticide die out. (b) Genetic drift: </s
- ScienceClass 10CBSE
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?
Solution: Given information is not enough to tell us which characteristics are dominant – blood group A or O. Blood type A is always dominant in ABO blood, and blood type O is always recessive. Here, the father’s blood group may be genotypically AA (homozygous) or AO (heterozygous), whereas that of the mother can be OA or OO.
- ScienceClass 10CBSE
How do Mendel’s experiments show that traits are inherited independently?
Solution: Mendel’s experiments show that traits are inherited independently through his dihybrid cross experiment. The experiment involved him using two traits – namely, seed shape and seed colour. The colour yellow (YY) is dominant over green (yy), while the round shape (RR) is dominant over the wrinkled shape (rr). The F2 progeny of the dihybrid cross resulted in a phenotypic ratio of 9:3:3:1; therefore, 9 plants with round yellow (RRYY) seeds, 3 plants with round green
- ScienceClass 10CBSE
How do Mendel’s experiments show that traits may be dominant or recessive?
Solution: Mendel showed that the traits could either be dominant or recessive through his experiments that focused on the mono-hybrid cross. The experiment involved him crossing tall (TT) pea plants with dwarf (tt) pea plants. The resultant plants which formed after fertilisation represented the F1 (or filial) generation. All the F1 plants were tall. Mendel then proceeded to self-pollinate the filial generation plants, and the result was that 1/4th of the plants obtained in the F2 gen
- ScienceClass 10CBSE
How does the creation of variations in a species promote survival?
Solution: Genetic variations enable the species to better adapt to changes in its environment. Moreover, it is an important force in evolution as it allows the frequency of alleles to increase or decrease through natural selection. These variations will determine the difference between extinction or continuation of the species.
- ScienceClass 10CBSE
If a trait A exists in 10% of a population of an asexually reproducing species and trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Solution: Trait B is more probable to arise early as this trait has already been existing and replicating in a larger percentage of the population as compared to trait A.
- ScienceClass 10All
What is variation in biology class 10
Variation in a different form or combination of characteristic that is found in our population. We refer to these variants as trait. Variations can arise due to various reasons Copying fo DNA is done by enzyme DNA polymerase. Being a biochemical reaction, it cannot have 100 accuracy. The errors when made are attempted by the enzyme’s exonuclease activity but even then several discrepancies seep in Variation could result from the transfer of DNA between organisms