1. The appearances of fireflies at dusk is an example of a circadian rhythm because it's happens daily. The correct option among all the options that are given in the question is the third option or option "c".
2. During migration, animals undertake a seasonal movement. The correct option among all the options that are given in the question is the first option or option "a".
Answer:
The correct answer will be option-A
Explanation:
The ecological population is the group of the organism belonging to the same species which live or is found in the particular area and can interbreed.
Since in the given question, the redwood trees live in the same geographical area (forest) which can interbreed shows the population. The other examples represent the community which consists of more than one species.
Thus, option-A is the correct answer.
the skin covering the human body consists of 2 layers.
Experimental technique I believe
There is a valve at the meeting point between each ureter and the bladder prevents the back flow of urine from the urinary bladder to the kidney