The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
The answer to this is all of the above.
1. C
2. A
3.D
4.B
We know that arteries from the aorta and arteries from coronary arteries supply oxygenated blood to various parts of the body. What separates these two is the coronary arteries’ ability to deliver oxygenated blood to the heart.
We know that the inferior vena cava delivers deoxygenated blood to the lower (hence inferior) part of the body and that the superior vena cava delivers deoxygenated blood to the upper (superior) part of the body; they follow the same deoxygenated rule and strictly deliver nutrients to certain parts of the body.
I hope I helped! :)
Most of the mutations have no effects whatsoever on the organisms but some can be dangerous. There are two types of mutations that cause harm to the organism's ability to survive:teratogen muations are the mutations that form inside the uterus when the fetus is still developing and can even kill it or cause severe malformations that lead to death in the early life. Carcinogen mutations are the ones that lead to the formation of neoplasms(masses of cells that divide uncontrollably, basicly cancer).
<span>The most expectant evolutionary feature would be longer necks. This will enable the tortoises to reach the higher grass. This <span>would occur through natural selection that would favor the extreme traits (alleles of long neck) of long necks in the population.</span></span>
