In female kangaroos (marsupials),multiple choice the paternal x chromosome is always inactivated into a barr body. neither the maternal or paternal x chromosome is inactivated into a barr body. either the maternal or paternal x chromosome is randomly inactivated into a barr body. both the maternal and paternal x chromosomes are inactivated into a barr body, but only in about 50% of the total cells. the maternal x chromosome is always inactivated into a barr body.

The paternal X chromosome is always inactivated into a Barr body.

Explanation:

Marsupials also balance the number of  X linked genes present in male and females by inactivation of one X chromosome in their females. Kangaroos and other marsupials exhibit inactivation of the paternal X chromosome. In marsupials, the paternal X chromosome is always inactivated and is present in the form of the Barr body in the cells of the females.

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:

the electromagnetic energy from the sun arrives in the form of visible and invisible light.