In active transport, molecules move against a concentration gradient, therefore
molecules move from a region of low concentration to a region of high concentration
molecules move from a region of high concentration to a region of low concentration
the concentration gradient has little effect on the movement of molecules
molecules force their way through special channels
Correct answer is A
No explanation has been provided for this answer.
Which of the following Best explains why It is difficult to see clearly in dim light?
Initially the eyes cannot operate when the light is dim
The choroid reflect all the light that enters the eye
Too little light reaches the retina and so the cones may not be stimulated at all
Dim light causes the pupil to close up so that not much light enters the eye
Correct answer is C
No explanation has been provided for this answer.
Which of the following pairs of organisms exist as colonies?
Obelia and Euglena
Pandorina and Volvox
Chlamydomonas and Amoeba
Hydra and Spirogyra
Correct answer is B
No explanation has been provided for this answer.
Which of these organs can be considered vestigial in humans but functional in other mammals? The
liver
appendix
rectum
stomach
Correct answer is B
No explanation has been provided for this answer.
Which of the following traits is not a morphological variation in humans?
Ability to taste PTC
Colour
Fingerprints
Size
Correct answer is A
No explanation has been provided for this answer.