Isotopes are variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos and topos, meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table.
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.
What are the questions that go with the model?