If there are 20 centromeres in a cell how many chromosomes are there?

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots

How do the sperm cells get from the stigma to the ovules? a. they slide down the petals to the bottom of the flower. b. they travel through pollen tubes. c. they travel along filaments. d. insects carry the sperm cells from the stigma to the ovules.

Lumps of iron and manganese ore called can be harvested from the seafloor near underwater volcanoes.