Read the following question. “how fast do hummingbirds fly? ” why is the question a scientific question? it expresses an opinion. it can be tested during field studies. it can be answered without an investigation. it asks about phenomena that cannot be measured.

Ans.

A proper scientific question includes certain features. It should be answerable (have real answers), can be verified (means it can be tested by measurements  or experiments), and should lead to a falsifiable hypothesis (it should make an hypothesis that can be failed by others). The given question is a scientific question as it the speed of hummingbirds can be measured experimentally, it is answerable, and a hypothesis can be made on experimental results.

Hence, the correct answer is option, 'it can be tested during filed studies.'

answer; ///as energy flows through an ecosystem,energy (decreases) at each

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.