Blood donations can be used to save lives for people suffering from blood loss due to traumatic injury. However, other times only certain components of the blood are needed. For example, platelets can be donated and used to help in cases where a clotting factor is missing in a patient. The fractioning of blood into its components is shown here. What experimental design was most likely used to provide evidence for the success in blood fractioning?

A) Blood donations were collected and separated by their different sizes.
B) Blood donations were collected and separated by the temperature at which they boil.
C) Blood donations were collected and separated by their attraction to a magnetic field.
D) Blood donations were collected and separated by their different densities in the mixture.

D

Explanation:

Blood bags collected from the donor and centrifuge the blood components are separated by their different densities in the mixture. As cellular components have a higher density they settled at the base of the blood bag while plasma has lower density it is at the top of the blood bag and clear in the texture. So, on the basis of density, blood components can be separated.

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: