Exam 21: Development and Aging

One hypothesis for why we age, or at least why our cells age, is that every time that mitosis occurs, ________ at the ends of chromosomes shorten, and eventually the cell runs out of these units at the ends of chromosomes.

The duration of a person's life is referred to as

Match the special structures of the fetal cardiovascular system with their descriptions. -shunt that bypasses the liver

Match each organ to the germ layer from which it develops. Answers may be used more than once. A) endoderm B) ctoderm C) ectoderm D) mesoderm -enamel of teeth

In the fetus, the ductus arteriosus shunts blood from the pulmonary artery directly to the lung.

The blastocyst begins to form a second hollow cavity that will eventually become the

The extra-embryonic membrane known as the ________ is the source of germ cells that eventually develop into gametes.

Labor is triggered when which one of the following fetal organs or systems is mature?

Match each organ to the germ layer from which it develops. Answers may be used more than once. A) endoderm B) ctoderm C) ectoderm D) mesoderm -nervous system

Research on the aging process shows that wounds of the elderly heal more slowly and that they are more susceptible to disease. These are problems associated with an aging ________ system.

Why is taking the first breath hard work for the newborn?

During the first day or so after birth, the breasts produce a watery milk called

Match each organ to the germ layer from which it develops. Answers may be used more than once. A) endoderm B) ctoderm C) ectoderm D) mesoderm -liver and pancreas

The figure above shows the development of the human embryo during days 19-24. Which of the following organs forms from the ectodermal folds of the embryo?

Which cardiovascular structures in the fetus shunt blood away from the fetal lungs?

The figure above shows a human sperm. Which part of the sperm contains the most mitochondria for generating ATP?

All of the following can pass through a healthy placenta EXCEPT which one?

If you have ever had a chance to witness a childbirth, then you know it is an amazing event. However, even after the baby has been removed from the mother, her work is not complete in terms of labor. Why?

Match the special structures of the fetal cardiovascular system with their descriptions. -structure that transports oxygenated blood from the placenta to the fetus ovale

Prior to the union of the nuclei of the egg and sperm, meiosis II is completed by the ovum.