The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Scientists can access the risks of trans fats by conducting an appropriate experiment which will show the effects of the fats on the human system.
This can be done by feeding known quantity of trans fats to rats over a specific period of time. During the period, the change in the rat weights will be measured on the daily basis and every other changes that is noted in the rats will be noted down. A control group of rats will be included in the experiment; these rats will be given normal rat feeds and not trans fats.
When the period of feeding is completed, the rats will be killed, all the organs in the rats such as liver, blood, brains, kidney, etc will be harvested and these organs will then be biochemically analysed in order to compare the changes in them with that of a normal rats.
Rats are usually used in biochemical research because their systems and that of human is comparable. Any negative effect of trans fats that is noted in the rats will also hold true for human beings.
Diffraction occurs when a wave moves through an opening in a barrier. This causes the wave to change direction and spread out.
Waves can behave in three different ways depending on the obstacles they encounter. They can reflect, refract or diffract. In diffraction, waves such as sound, light or water either bend around small objects that obstruct their passage or spread out as they travel through a gap in the barrier.
The degree of diffraction forms a direct relationship with wavelength. It generally increases as wavelength increases. Conversely, the amount of bending lessens as wavelength decreases. However, if the opening of the barrier is smaller than the wavelength, the effect of diffraction is not easily observed. Hope this helps.
The production of these crops is centered in the eastern third of the state but there are notable concentrations elsewhere, particularly in the river valleys of the Arkansas River (central Arkansas) and the Red River (southwest Arkansas).
Answer:
as a teacher i can help
Explanation:
q1 is d, a phenotype is how you look, so its 4. q2 is b, its one possiblity out of 4, so its 1. q3 is a, thats a pedigree chart, so its 7. q4 is c, if they both are expressed they are co dominate, so its 2.
