Question 18(Multiple Choice Worth 2 points) (06.04H MC)
Which of the following occurs during birth?
O Pituitary hormones are released, and the fetal heart begins to beat.
The fetal nervous system becomes activated, and the cervix opening expands.
The fetal nervous system becomes activated, and the fetal heart begins to beat.
O Pituitary hormones are released, and the opening of the cervix expands.

Classify the structures as homologous or analogous, depending on their structure and function.

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.

Which of the following statements is accurate about evolution? question 10 options: natural selection only eliminates odd individuals. evolution means that a population never has changes in its genetic frequencies. mutations are always harmful. evolution means that a population undergoes changes in its gene frequencies over time.