<u>Answer</u>:
1. The purpose of the uninoculated control tubes used in the oxidation fermentation test is to serve as basis of the medium for the color comparison and that it is sterile.
2. It is necessary to use two controls in order to illustrate the no color change (green color) under both aerobic and anaerobic conditions.
3. The purpose of the experiment is to determine if the organisms utilize the carbohydrate and thus is fermentative. This will result in a color change from green to yellow.
Thus, the medium in one tube is sealed with a layer of paraffin to prevent diffusion of oxygen. This tube will show that the medium is unaffected by the lack of oxygen.
The second tube will allow the diffusion of oxygen. This tube will show that the medium does not change color naturally in the presence of oxygen. Thus, the color changes will be caused only by the fermentation process of the organisms.
Answer: Valves in the veins
Explanation: The flow of the blood inside the body takes place through the veins and arteries. The oxygenated blood from the heart is supplied to the different parts of the body.
The blood flows from the capillaries to the venules and from there to the veins. The blood moves in the veins by the rhythmic movement of the smooth muscles in the body.
Most of the blood moves against the gravity so there is a chance that it can backflow so to prevent this there are valves in the veins known as one way valves.
I think it’s tea because it says that the sunlight is more impacted on the zone
The answer is D
Which of the chemical where are the chemical