A geneticist crossed pure breeding black mice with pure breeding brown mice. All the mice in the F1 generation had black coats. When these mice were crossed, they yielded 961 black coated mice and 317 brown coated mice. Fill in the new combinations of alleles in the F2 generation.

The correct answer is - the brown allele is not independent from the black allele and disappears in the F1 generation.

Explanation:

IN this question it is given that there is a cross between pure black and pure brown breed and the F1 generation has all-black coat offspring and their self cross produced 961 black and 317 brown.

The black coat offspring is three times than the brown coat offspring in F2 generation which means they have 3:1 ratio that comes in the self cross of heterozygous only there for the F1 generation black coat offspring have the heterozygous genotype for the trait,

Thus, the brown allele is not independent of the black allele and disappears in the F1 generation.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: