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.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
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?
Why do we apply paint on iron articles?
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
Explain the following in terms of gain or loss of oxygen with two examples each.
(a) Oxidation
(b) Reduction
What do you mean by a precipitation reaction? Explain by giving examples.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
Do basic solutions also have H+(aq) ions? If yes, then why are these basic?
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
What does one mean by exothermic and endothermic reactions? Give examples.