Answer:
DNA molecules have negative charges, and so when placed in an electric field they migrate toward the positive pole.
Explanation:
Electrophoresis is a technique that <u>uses differences in electrical charge to separate the molecules in a mixture</u>. DNA molecules have negative charges, and so when placed in an electric field they migrate toward the positive pole. The rate of migration of a molecule depends on two factors, its shape, and its charge-to-mass ratio.
A gel, which is usually made of agarose, polyacrylamide, or a mixture of the two comprises a complex network of pores, through which the DNA molecules must travel to reach the positive electrode. The smaller the DNA molecule, the faster it can migrate through the gel. Gel electrophoresis, therefore, <u>separates DNA molecules according to their size.</u>
Because different genes are switched on and off in each type of cell.
<span>As blood moves away from the heart toward the tissues, the relative size of blood vessels decreases, the blood pressure drops, and the velocity of blood flow slows.
The size of the arteries progressively decreases as they branch out from the major arteries of the body. Once the arteries are the size of the arterioles, the resistance to blood flow increases and velocity of blood flow slows then blood pressure drops.
</span>
Answer:
The correct answer is ''METAPHASE I.''
Explanation:
Metaphase I is the stage in which chromosomal studies are generally performed, because its morphology is very clear. The chromosomes, moved by the mitotic spindle, are placed in the center, between the two asters and form the so-called metaphase plate, in which the chromosomes are positioned in such a way that the kinetochore of each sister chromatid are oriented towards the opposite poles. Keeping chromosomes on the cell equator implies a balance between the forces of the microtubules that tend to move the kinetochores toward opposite poles, so positioning them in the center involves a great deal of energy.In each kinetochore, between 20-30 microtubules can be anchored, which exert traction force towards the pole from which they come, so the metaphase plate is maintained by the balance between the opposite forces of the poles on the chromosomes, which hold their sister chromatids by centromeric cohesin.
