At what stage of mitosis is there a regulatory checkpoint that detects chromosomal abnormalities

What is the chance of two parents with blood types ab and o producing an offspring with blood type o a.0% b.25% c.75% d.50%

What happens whenever a net force acts on an object

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.