why do only half of each parents allelesis given to the offspring?

Question

first one who answers CLEARLY gets ten points

Answer 1

The parent's cells undergo meiosis to make the reproductive cells which are the eggs and sperms.

During meiosis, the pairs of homologous chromosomes are separated from each other. The alleles are on these pairs of chromosomes.

So an egg or a sperm gets only one allele from each pair of alleles.

Then when an egg and sperm join together, the child will have pairs of alleles again - one from Mom and one from Dad to make each pair.

Answer 2

Each person has a total of 46 chromosomes (diploid). When fertilization takes place each parent donates 23 chromosomes (haploid) to create a diploid zygote. This process stems from Mendels law of segregation. The law states that when gametes are formed (sex cells) that they segregate into haploid cells (23 chromosomes). Then, those haploid cells join together (one set from each parent) to form a fetus with 46 chromosomes.

Why? This is what creates variablity amongst human beings and serves as the foundation for evolution. Also, remember that there are alot of genetic recessive diseases (ie hemophilia). By segreggation, you lower the risk of a fetus receiving 2 mutant genes for the disease. If a recessive gene comes from the mother and a dominant gene from the father, the baby will be healthy.

Answer 3

Basically, half of the offspring's chromosomes come from mom & the other half come from dad. If we received all chromosomes from both, we would just keep doubling our chromosomes in each susequent offsrping.
Example: normal is 23 chromos from mom + 23 chromos from dad= normal 46 chromos.
If kept doubling, this would happen: 23+23=46 original
If offspring donated all 46 & another offsrping donated all 46 you would have 46+46=92. And as you can see we would keep increasing the amount of chromos.