Answer:
biological species concept
Explanation:
The biological species concept is the most commonly used and acceptable definition of species, which explains that a group of organisms can be referred to a species if members of the group can interbreed successfully to produce viable offspring that are also fertile. It explains that there tend to be reproduction barriers that would prevent different species of organism from successfully interbreeding. Also, that two organisms have the same appearance, do not necessarily mean they belong to the same species. For example, a horse and a donkey were interbreed to produce an offspring called the mule, but, the mule was found to be infertile. A horse and a donkey are different species, even though they have close appearance.
Answer: the answer is False
Question 3, the answer is Zygote
Sorry that's the only one I can answer for sure right now.
Answer: If we kill all the organisms in one trophic level, then transfer of energy as well as matter to next higher level will stop. It will lead to over- population at one particular level causing amongst the individuals. This would seriously disturb the food chain and can cause the collapse of an ecosystem even.