HELP!!! The DNA double helix is composed of:

a) 2 Polynucleotide strands
b) 2 Chromosomes
c) Protein
d) RNA

Four types of motile cells in human body?

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one

Which atmospheric later is where earths northern and southern lights occur