Because science is always changing and every time you cam come up with a new outcome.
The statement that is a well-written hypothesis about DDT and its effects on the environment is as follows: If DDT levels in the environment increase, then the number of predatory birds will decrease (option B).
<h3>What is an hypothesis?</h3>
Hypothesis is a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation or experimentation.
Hypothesis is widely regarded as an educated guess because it predicts the outcome of an experiment and can be tested to either be true or false.
A hypothesis is usually written as an IF, THEN statement.
Therefore, the statement that is a well-written hypothesis about DDT and its effects on the environment is as follows: If DDT levels in the environment increase, then the number of predatory birds will decrease.
Learn more about hypothesis at: brainly.com/question/13025783
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Answer is the phylum is Pteridophyta. Pteridophytes are first land plants, examples ferns, <em>Lycopodium, Selaginella. </em>Members have liginified cells and developed conducting tissues called vascular system to conduct water and synthesized food. They reproduce through spores, seeds do not develop in pteridophytes.
Answer:
i believe the answer would be d, all of the above
Explanation:
all are questions relating to gene variability of a species, which would be what the population geneticist would specialize in. the scientist must ask questions and then conduct research. i hope that helps :) have a lovely week