The Living World 8th Edition by George Johnson

تمرين 12

An egg and a sperm unite to form a new organism. To prevent the new organism from having twice as many chromosomes as its parents,
A) half of the chromosomes in the new organism quickly disassemble, leaving the correct number.
B) half of the chromosomes from the egg and half from the sperm are ejected from the new cell.
C) the large egg contains all the chromosomes, the tiny sperm only contributes some DNA.
D) the egg and sperm cells only have half the number of chromosomes found in the parents due to meiosis.
The diploid number of chromosomes in humans is 46. The haploid number is
A) 138.
B) 92.
C) 46.
D) 23.