Apopulation that is decreasing in size will have an age-structure histogram shaped like a(n): 1) inverted pyramid, with a narrow base representing a small number of young individuals.2) diamond, with a wide center depicting a large number of individuals that have reached reproductive maturity. 3) pyramid, with a wide base at the bottom representing a large number of young individuals. 4) rectangle, with an (roughly) equal number of individuals in each age group.

The correct answer is - 1) inverted pyramid, with a narrow base representing a small number of young individuals.

The populations that are decreasing are usually population in countries that are highly developed. The conditions for living are excellent, the medical care on high level, life expectancy very high, but the birth rates very low.

In this type of conditions, there's smaller and smaller number of young individuals, with the middle aged population being much bigger, and the older population being constantly on the rise. This will give the age-structure histogram a reverse shape than what it is supposed to have, it will be similar in appearance like a inverted pyramid, meaning that the population is aging and that it will be constantly on a decline in the future.

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: