Lternative splicing can process the same pre-mrna into different forms of mrna. which one of the following reasons best explains why this pre-mrna can't be processed into a mrna containing only (exon 1-intron a-exon 3)?
a. the spliceosome can not excise rna sequences bounded by two 5' splice sites.
b. the spliceosome can not excise rna sequences bounded by two 3' splice sites.
c. the spliceosome can not excise rna sequences bounded by an upstream 5' splice site and a downstream 3' splice site.
d. the spliceosome can not excise rna sequences bounded by an upstream 3' splice site and a downstream 5' splice site.

Dr. kaylan is an ecologist who studies bird behavior. she sets up an experiment to test which type of food crows are most likely to eat when given a choice between walnuts, corn, and sunflower seeds. to perform her experiment, dr. kaylan places three food bins in an area frequented by cows. each bin contains one of the three food types. then, she measures how much of each food type is eaten every day for a month and summarizes the results of her experiment in the pie chart below. based on her results, dr. kaylan concludes that crows choose to eat corn more frequently than other food sources because it has a higher nutritional value. what is a reasonable alternate conclusion that can be drawn from dr. kaylan's data

Time ! for a smell to begin the process of registering in your brain, first you must a) inhale odor molecules into the nasal cavity b)transduce scent chemicals c)have a scent to inhale d)all answers can work

Describe the function of the endomembrane system? what organelles are involved?