Well, I don't fully understand your question. I think I know what you're getting at though.
In a system of sexual reproduction, you have genes coming from both an egg and the sperm. Therefore, it'll only contain half the total amount of chromosomes (46 in humans). A sperm will have 23, and the egg will have the other 23. Is that what you meant why the chromosomes are cut out in pairs? If that wasn't your question, please elaborate and I'll return to answer it to the best of my capabilities.
Answer:
I would say We don't have enough evidence or Cell theory is still changing.
Explanation:
There are so many cells in everything so it's almost impossible to know exactly what is going on. Theories about cells have been going on for over 500 years, and we still don't know exactly what is what.
Answer:
It means it disapear from the population during a certain time period
Explanation:
Lost allele often refers to fixed allele and it is a phenomenon when only one allele of a gene is present in the population. This event occurs usually as a consequence of a disaster, for example forest fire. After the disaster, only certain individuals survive with the fewer alleles that the initial population. Other alleles are lost.
I believe the answer is an egg
