Get twenty people, from various genders and ages, to be your testees. Create a random test that has both analytical and logical problems, and get the 'testees' (I have no idea if this is a word or not) to do the test before and after spending time outdoors.
An independent variable is how much time they spend outside, and the dependent is how well they function afterwards. (I think).
The constant is what stays the same, so most likely the tests in this case (if taking my example)
I don't really know what you mean by control, though...
This is what I would've done if it was my homework assignment, I'd suggest looking over my answers to see if they're accurate or not. Hope I helped, and good luck.
Answer:
The correct answer would be B) homologous.
Homologous organs refer to the set of organs which have different appearance and function but share common anatomy due to common ancestry.
For example, the forearm of human, forelimb of the horse, wing of a bat, wings of birds, and seal's flipper share common underlying anatomy. They are made up of same sets of bones (humerus, radius, ulna, carpels, metacarpals, and phalanges).
These organs are adapted to perform different functions in an environment.
It is also observed that these organs developed in the same manner in the embryo and from similar origins.
blood flows at a high pressure, so if the arteries are thin and less muscular, the arteries can explode due to the pressure. so it needs thick and muscular properties so that it can withstand the increasing pressure of the flow of blood.
im not sure why it needs to be elastic. Hope it helped :)
Out of the choices given, the mechanisms that drives evolution is natural selection. The correct answer is B, natural selection.
Yes I think you are right. It does not contain setae for food to travel to the anus. But it's something else that develops the food into poop and travels through anus
Hope this helps :)
