The correct answer is (b) genetic material comes from two parents of the same species.
Explanation: Sexual reproduction involves the fusion of gametes from two different individuals of the same species, leading to offspring with a combination of genetic traits from both parents, resulting in greater variation compared to asexual reproduction where an offspring inherits the genetic material from a single parent.
Why other options are incorrect:
(a) sexual reproduction is a lengthy process:
While sexual reproduction can be longer than asexual reproduction, the length of the process is not the primary reason for increased genetic variation.
(c) genetic material comes from two parents of different species:
Sexual reproduction always involves the fusion of gametes from individuals of the same species. If gametes came from different species, the resulting offspring would not be viable.
(d) genetic material comes from many parents:
Sexual reproduction typically involves only two parents contributing genetic material to the offspring.