Proteins that eukaryotes use to turn genes on and off by allowing transcription to occur or blocking it are called
a. repressor
b. introns
c. transcription factor
i think its transcription factor. but, i want to make sure! !

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

In general, are there any major differences that you can see? explain

What is used as a template during replication? a- mrna b- trna c- rrna d- dna