A small plastic cup is floating in a pan of water. Inside the cup is one quarter. For an experiment, students take turns adding quarters to the cup one quarter at a time. Making observations after each quarter is added to the cup, the students will notice something about the water level in the pan. What do they notice about the water level? A) The cup will sink.
B) The level will go up.
C) The level will go down.
D) The level will remain the same.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

b. heterotroph

explanation:

i think it is d. objects resist changes in their state of motion.