When does the cell have to use active transport?
a. when the cell is low on energy
b. when the cell is in a highly concentrated solution
c. to move molecules across the membrane quickly
d. to move molecules across the membrane against a gradient

Ayoung boy has been found and police are trying to locate his family they take a dna sample from him and begin collec dna samples from families who have missing children if police use dna samples only from the fathers, which type of dn technology can they use to identify the boy's parent? y-chromosome analysis omtdna (mitochondrial dna) analysis vntrs (variable tandem repeats) o pcr (polymerase chain reaction) analysis

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give