Which of the following is a factor that can stop normal cells from growing? Select one: a. contact with other cells b. growth factors c. a cut in the skin d. cyclin that has been taken from a cell in mitosis

a. contact with other cells

Explanation:

Contact inhibition prevents cells from further growth. When a sungular cell is in contant with another, it will stop it's growth right away.

In cell biology, contact inhibition as to do with two distinct but close phenomena: contact inhibition of locomotion (CIL) and contact inhibition of proliferation (CIP).

CIL is regarded as the avoidance attributes shown by fibroblast-like cells when in contact with each other resulting in changes of their movement in a separate direction to prevent future collision. In times when such collision is unpredictable, a separate biological process is observed resulting the cells growth to come to an end in a cell-density reliat way.

Contact inhibition leads to regulation of normal tissue growth, differentiation, and development.

It is essential to recall that both forms of regulation are usually silenced and inhibited in times of organogenesis in the course of embryonic development and tissue and wound healing. Also, contact inhibition of locomotion and proliferation are silenced in cancer cells prompting tumorigenesis.

it restores trees to areas where they once grew.

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: