Type your answer in the box. The video reports a decline in the number of "packers" in California. What are packers, and what challenges does
their decline pose to firefighters who fight wildfires?

Packers ride mules and drive strings of pack mules. It’s difficult to drive trucks and other vehicles in the woods. Packers using mules can deliver supplies to firefighters who are working in the deep woods. Fewer people working as packers will make it more difficult for firefighters to get the supplies they need—such as gasoline, water, and food—while they are fighting fight wildfires.

Explanation:

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: