Out of the following give choices;
a. All DNA strands
contained only the heavy nitrogen isotope.
b. Half of the DNA strands contained only the light nitrogen
isotope.
c. All DNA strands contained both heavy and light nitrogen
isotopes.
d. All DNA strands contained only the lighter nitrogen
isotope.
The answer is b. Meselson–Stahl experiment demonstrated the semi-conservative model of DNA replication.
When DNA is replicated, one strand of the new double
helix strand is the parent's strand while the other is the newly synthesized
one. This made the semiconservative model stand out over the other two, dispersive
and conservative models.
Answer:
1: (The arteries carry blood away from the heart; the veins carry it back to the heart.)
2: (In the systemic circulation, the left ventricle pumps oxygen-rich blood into the aorta.)
4: (Blood, which is low in oxygen, is collected in veins and travels to the right atrium and into the right ventricle.)
Explanation:
The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body. It consists of the heart and the blood vessels running through the entire body. ... In the systemic circulation, the left ventricle pumps oxygen-rich blood into the main artery (aorta).
The arteries carry blood away from the heart; the veins carry it back to the heart. ... The blood travels from the main artery to larger and smaller arteries and into the capillary network. There the blood drops off oxygen, nutrients and other important substances and picks up carbon dioxide and waste products.
The inferior and superior vena cava bring oxygen-poor blood from the body into the right atrium. The pulmonary artery channels oxygen-poor blood from the right ventricle into the lungs, where oxygen enters the bloodstream. The pulmonary veins bring oxygen-rich blood to the left atrium.
-A Helping Friend
Answer:
The correct answer is B. weight loss
Explanation:
Calorie is considered a unit of energy and athletes like basketball players require more calories than common people. Calories are present in our food and every food provide a different amount of calories to us.
To gain weight people require to consume more calories than they burn and to reduce weight people must burn more calories than they consume. So losing weight by theo shows that theo is not taking enough calories to support his activity.
Therefore theo should improve the calorie intake up to that level where he can maintain his body weight. Therefore the correct answer is B.
Oxygen is used up in the body of most organisms and Carbon dioxide is released. The body uses oxygen to break down glucose to supply energy tot he body. In result of this reaction carbon dioxide and water is released into the system along with energy. The carbon dioxide is then exhaled into the air by the respiratory system of the organisms.
Answer: The cell synthesizes mRNA and proteins preparing it for cell division.
Explanation: During this phase the cell also synthesizes enzymes and nutrients for the process of cell division.
