Answer:
<h2>D. Radioactive nitrogen in the DNA of the bacterial cells is present in one strand of the DNA of all of the cells.</h2>
Explanation:
As given here,
The nitrogenous base of DNA is radio active labeled, and is grown in normal unlabeled medium.
As we know that DNA replication occurs in semi-conservative way, so after one round of replication, one parental strand would be radio active and other newly synthesized strand would be unlabeled.
So here, after one round of replication, one strand of all the newly synthesized DNA would be radio active and other strand would be normal.
Answer:
Glucose entering the intestines from the villus.This is by active transport.The latter is defined as the movement of molecules and solutes from the region of lower concentration to the region of higher concentration against the concentration gradient.
Explanation:
All the above options depends on the diffusion gradients from one higher region to another.e.g oxygen passing from high concentration from outside to lower concentration in blood stream,like wise Co2 from higher concentration from inside to outside,with passive diffusion lipids and water enter the small intestine(note amino acid and glucose,and fructose are different).
Active transport( through sodium dependent transporter) transports glucose to the intestine from the villus.This is movements against concentration gradient because,glucose molecule are concentrated in intestine,and needed by the cells, in the body.Therefore they must be transported as a fast rate inn the blood .
However the absorption by the villi is very slow,therefore active transport is needed to move these against the concentration gradient into the intestine.And finally the blood.
If this were to be moved by passive diffusion,the high concentration in the intestine will force this back into the villi
Therefore extra energy is needed by active transport for the glucose molecules to enter the intestine from the villus.
C) transposons or jumping genes.
hope this helps you out good luck.!!!!
Answer: the answer to this is D because these rays can show you where the fire is located even if it is enveloped in a cloud of gray and black smoke that prevents you from seeing it.
Explanation:
Answer:
The correct answer will be option-A
Explanation:
The centrifugation of the blood shows that 45% of the blood is composed of the cellular content and 55% blood plasma or liquid.
Erythrocytes or red blood cell constitute for about 41% of the total blood cells which transports the oxygen by binding it to the haemoglobin. The presence of haemoglobin is the reason the cell appears red which cause the color of the blood to appear red.
The remainder of the cell is white blood cells or leukocytes which play important role in providing the defence mechanism against the pathogen.
Thus, option-A is the correct answer.
