Question

the human genome has an estimated 25,000 genes on 23 chromosomes that can be affected by crossing - over and assorted into gametes. these gametes can then randomly combine into a diploid cell during fertilization. given these numbers, about how many different combinations of chromosomes could be found in diploid offspring? thousands tens of thousands millions trillions

Explanation:

Step1: Recall the principle of chromosome combination

During meiosis, each gamete receives one chromosome from each of the 23 chromosome - pairs in the parent. The number of different combinations of chromosomes in a gamete due to independent assortment is \(2^{23}\) for each parent.

Step2: Calculate the number of chromosome combinations in diploid offspring

When fertilization occurs, the number of different combinations of chromosomes in the diploid offspring is the product of the number of combinations in the sperm and the egg. Since each parent can produce \(2^{23}\) different gametes, the number of different combinations of chromosomes in the diploid offspring is \(2^{23}\times2^{23}=2^{46}\).
We know that \(2^{10}\approx1000 = 10^{3}\), so \(2^{46}=(2^{10})^{4}\times2^{6}\approx(10^{3})^{4}\times64 = 64\times10^{12}\), which is in the trillions.

Answer:

trillions