What does an organism's phenotype describe?

a. the allele combination for a trait
b. the physical appearance of a trait
c. the number of alleles on a gene
d. the number of different traits inherited

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

How far down have geologists drilled holes ? (science) a: 3.8 km b: 12 km c: 100 m d: 1200 km

The picture below shows two galaxies. spiral galaxy and elliptical galaxy which of these statements best describes a similarity between the two galaxies? (2 points) both have elongated centers. both have centers shaped like bars. both change their shape from time to time. both are held together by gravitational forces.