A researcher in Broward County, Florida designed an investigation to test what effect eating different types of food would have on blood insulin levels. She selected 10 male
subjects who were all 25 years of age and in good health. The experiment took place
over 3 days. At 8:00 a. m. on each day, the subjects ate a meal consisting of only 1 type
of food. They had their blood insulin levels measured after consurning the meal. On Day
1 they ate a high fat diet, on Day 2 they ate a high protein diet, arnd on Day3 they ate a
high sugar diet.
What is the independent variable in this experiment?

the males age

Explanation: it didn’t change throughout the whole experiment but it can also be the time they took the food also .

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:

i think it is dna, i'm not totally sure but i think it might be.