Answer:
The earliest known life-forms are putative fossilized microorganisms, found in hydrothermal vent precipitates, that may have lived as early as 4.28 Gya (billion years ago), relatively soon after the oceans formed 4.41 Gya, and not long after the formation of the Earth 4.54 Gya.
Explanation:
There are 4 thing that need to happen for natural selection to occur:
1) reproduction
2)heredity
3)variation in fitness or organisms
4)variation in individual characters of the population.
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:
Q1. A. An organism with favorable genetic variations will tend to survive and breed successfully
Q2. C
Q3.b. limited food resources
Q4.c. chromosome number
