Answer:
Sperm motility
Explanation:
Sperm motility is the property of the sperms to move properly through the woman's reproductive system during the process of fecundation. The sperms need to move into the female reproductive tract to fertilize the ovum and thus form the egg cell.
The Alveolar macrophages, Cilia and the mucus layer
Answer:
<em>The correct option is D) How is the number of frogs in Massachusetts affected by pollution</em>
Explanation:
A scientific question can be described as a question which can be answered through the scientific method of research. Based on the scientific question, a hypothesis can be formulated. For example, for the option D, the hypothesis can be 'if the pollution increases, then the number of frogs decreases.' A hypothesis is a tentative statement which can be tested through experiments. Based on these experiments, results are formulated and conclusions are drawn. The question mentioned in option D can be answered through this method hence, it is the correct option.
Vestigial structures. These are structural elements that once served a purpose but as the organism evolved now serves no purpose.
