Answer:
I'm not too sure specifically for 9th grade. Though I am in 12th grade right now and currently using the Edrolo biology textbook which is solely based on the key dot points/skills for the entire subject. They also include past exam questions or similar exam style questions both multiple choice and short answer for each topic and chapter within the book.
Explanation:
The population of Green-feathered birds decreases due to prefer other colour of male birds.
<h3>Why the population of Green-feathered birds decreases?</h3>
Green-feathered birds are becoming less and less common because of the female bird that choses the blue and red colour male for mating instead of green so that's why the population of Green-feathered birds decreases.
Learn more about mechanism here: brainly.com/question/1320373
D. Nucleus
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