During fertilization in humans,
a) a wave of ca2+ions is released in the fertilized egg’s extracellular space.
b) only one sperm binds to the unfertilized egg.
c) a sperm moves in a directed fashion until it encounters an egg.
d) several sperm pronuclei compete in the cytoplasm to fuse with the egg nucleus.
e) none of the above.

Sally, age 3 months, has a moist, red, vesicular rash on her cheeks, the backs of her hands, and her arms. her mother said sally was constantly trying to scratch the rash and often has difficulty sleeping. her father has a family history of allergic rhinitis and asthma. discussion questions. 1. review atrophic dermatitis from chapter 3 and discuss the pathophysiology of sally’s symptoms. 2. why is the father’s medical history significant, and what can sally expect as she grows up? 3. discuss the need to limit scratching, and describe practical methods to achieve this.

What is point source pollution of an aquatic ecosystem? a) pollution of freshwater sources b) pollution from many sources that combine into one c) pollution that occurs over a wide area; water that runs off from fields, parking lots, and other land surfaces d) pollution that can easily be identified with a single discharge source, such as an open pipe which drains into a body of water

¿cómo demostraron los experimentos de griffith que un factor hereditario estaba involucrado en la transformación bacteriana?