Answer:
The beating or fanning movements of three pairs of maxilliped flagella in crabs and crayfish modify exhalent gill currents while drawing water over chemoreceptors on the head. They play an integral part both in signalling by distributing urine odours, and in active chemosensation.
Explanation:
Answer:
this one`s been up for debate for awhile now.
1. it depends on the organism
learning about an organism could be considered 'easier' to study in different ways. for example, if you are studying marine life, you will most likely have to keep it in a water habitat to watch it alive. If you are studying a land species, then watching from it`s natural habitat will give you more accurate results. sometimes the environment can affect an organisms internal systems more than you may think. this leads into my second point.
2. it depends on what you are trying to study
if you are trying to learn about the mating process, seasonal activity, migration, or external behavior, then monitoring it from it`s natural habitat or an area that is a close copy is your best option. but if you are looking into studying internal organs/systems or cells, then in <em>most</em> cases, the organism will need to be taken out of its natural habitat. only in very careful situations is it left in a habitat during examination.
Answer: Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Explanation:
I’m confused of the question your asking,can you give me more details?
