Which of the following must happen for a transcript of the lac operon genes to take place?
a. the repressor proteins bind to the dna molecules, and rna polymerase falls off.
b. lactose removes from the system.
c. the repressor proteins bind to the promoter sequences.
d. the repressor proteins falls off the dna molecules, and rna polymerase binds to.

In a classic experiment using pea shape, mendel conducted two separate genetic crosses. in the first cross the parent plants were “true breeding” for pea shape; one had round peas ( r )and the other had wrinkled (r). the first cross produced a filial 1 generation of all round peas. in the second cross, mendel bred plants from the filial 1 generation. this cross produced different results. out of approximately 1000 plants, about 75% were round and 25% were wrinkled.

What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell? a. passive transport b. diffusion c. endocytosis d. exocytosisc. endocytosis

Read the scenario below and answer the question that follows. hallie is reading a novel in the library when susan, her best friend, slumps down in a chair next to her. susan doesn't say anything, but hallie knows that susan is upset because she is slumping in her seat and rolling her eyes. a psychologist would explain that hallie is interpreting her friend's emotion based on a. the behavioral component of emotion b. her friend's ability to regulate emotion c. the verbal component of emotion d. the physiological component of emotion select the best answer from the choices provided a b c d