Answer:
1. 50% of the genome comes from each parent because it is crucial otherwise if the ratio changes, the zygote may not form and if formed the fetus may have some other kind of chromosome number related syndromes etc.
2. Sexual reproduction produces greater genetic variability than asexual methods. This is because of the process of crossing over during meiosis that exchange the segments of chromosome that is necessary for producing mutations and genetic variability.
3. 50% of chromosomes match with each parent because both of the parents contributed 23 chromosomes and exactly 50% of their genome.
4. The gametes must be produced by two different individuals cause that is the main purpose of sexual reproduction and give better survival like this to the forming next generation. Not to mention produces greater genetic variability among species.
5. Plants always produces both eggs because they are hermaphroditic in nature.
Darwin's idea of the survival of the fittest means that certain organisms are more likely to survive with they traits in particular environments. This is because some organisms are more fit to live in a given environment whether it be due to temperature, weather, or predators.
One example is that dark moths are more fit for survival than light moths in many areas because they are able to camouflage against dark tree bark.
Hope this helps.
Two identical DNA strands
D- both involve moving substances across a membrane
Reasoning:
-Active transport moves against the concentration gradient ( low to high)
-Passive transport moves higher to lower concentration