Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours withnonradioactive leucine. photographic emulsions are prepared at different times during the chase. where would the black spots appear on an emulsionprepared 3 hours after the pulse?
- rough er
- secretory vesicles
- golgi apparatus
- exterior of the cell

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.

Which of the following terms best matches this definition: the process where humans choose the traits that will be present in the next generation through breeding. question 4 options: genetic determinism artificial selection acquired selection natural selection