"what must occur before a newly made polypeptide is secreted from a cell?

a. it must be translated by a ribosome that remains free within the cytosol

b. its signal sequence must target it to the er, after which it goes to the golgi

c. its signal must be cleaved off before the polypeptide can be enter the er

d. its signal sequence must target it to plasma membrane, where it causes exocytosis

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

Drag each label to the correct location on the image. g organisms adopt different strategies and structures to make sure their offspring it uses. herds young into center of group produces many offspring at once to protect against high predation risk protects offspring until environmental conditions are ideal for growth coo b 13 1994 7 odos si . an . i

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.