The graph below shows  the  growth  rates  of  populations  of  bacteria  that  have  evolved  for  many  generations  at different culture temperatures (25°C, 30°C, and 35°C). Each population grows over only a limited range of temperatures (its thermal niche), which are bounded by its critical thermal limits. Within this range, growth rate increases with temperature up to a maximal value and then declines rapidly with increasing temperature. Growth rates are known to be the major determinant of fitness for these bacteria.

Which of the following is true concerning the thermal dependence of growth rate   between 25°C and 30°C in these populations?

#Question id: 11697

#Unit 7. System Physiology – Animal

In order for male differentiation to occur during embryonic development, testosterone must be secreted from the testes. What stimulates the secretion of testosterone during embryonic development?

#Question id: 11698

#Unit 7. System Physiology – Animal

A patient has an elevated plasma thyroxine (T4) concentration, a low plasma thyroid-stimulating hormone (TSH) concentration, and a thyroid gland that is smaller than normal. Which of the following is the most likely explanation for these findings?

#Question id: 11699

#Unit 7. System Physiology – Animal

Extracellular ionic calcium activity will be decreased within 1 min by which of the following?

#Question id: 11700

#Unit 7. System Physiology – Animal

As menstruation ends estrogen levels in the blood rise rapidly. What is the source of the estrogen?

#Question id: 11701

#Unit 7. System Physiology – Animal

Which of the following anterior pituitary hormones plays a major role in the regulation of a nonendocrine target gland?

#Question id: 11702

#Unit 7. System Physiology – Animal

An experiment is conducted in which antidiuretic hormone (ADH) is administered at hour 3 to four subjects (A to D). In the following figure, which lines most likely reflect the response to ADH administration in a normal patient and in a patient with central diabetes insipidus?