Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?
This is true that sexual reproduction give rise to more variations than asexual reproduction.
Sexual reproduction is responsible for evolution because these two parents are involved in forming a zygote by sharing their equal amount of genetic material to the offspring that confers a variation. More viable variations occur because error can occur in copying of DNA where mutations occur but this is very rare.
Sexual reproduction provides infinite chances of the new combinations of existing traits in two steps:- first, by the segregation (the formation of gametes by random separation of paternal or maternal chromosomes into the daughter cells. And second, at the time of fertilization by random fusion of male and female gametes to form a zygote.
And in case of asexual reproduction,
Unlike sexual reproduction, Asexual reproduction is not responsible for the evolution because in this type of reproduction process only one parent is involved to form the daughter cells. Very small or we can say no changes or variations occur in the progeny because the offsprings they gave arise are identical to the parent. And the division process is also different in this, it can occur through budding, binary or multiple fission.
So, we can say that sexual reproduction give rise to more viable variations than asexual reproduction.
Outline a project which aims to find the dominant coat colour in dogs.
How is the sex of the child determined in human beings?
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?
How do Mendel’s experiments show that traits are inherited independently?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Explain the terms analogous and homologous organs with examples.
How do Mendel’s experiments show that traits may be dominant or recessive?
How does the creation of variations in a species promote survival?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Why are traits acquired during the life-time of an individual not inherited?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
How does chemical coordination occur in plants?
Balance the following chemical equations.
(a) HNO3 + Ca(OH)2 → Ca(NO3)2 + H2O
(b) NaOH + H2SO4 → Na2SO4 + H2O
(c) NaCl + AgNO3 → AgCl + NaNO3
(d) BaCl2 + H2SO4 → BaSO4 + HCl
Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.
On what basis would you classify energy sources as
(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?
Are the options given in (a) and (b) the same?
Can any source of energy be pollution-free? Why or why not?
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
What are the disadvantages of fossil fuels?
A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.
How are fats digested in our bodies? Where does this process take place?
When is the force experienced by a current–carrying conductor placed in a magnetic field largest?