A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (i.e., halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap. If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage, then the flightless condition in these species could be an example of

TLS Online TPP Program

#Question id: 12207

#Unit 7. System Physiology – Animal

Which of the following hormones activate enzyme-linked receptors?

TLS Online TPP Program

#Question id: 12208

#Unit 7. System Physiology – Animal

Which of the following is produced by the trophoblast cells during the first 3 weeks of pregnancy?

TLS Online TPP Program

#Question id: 12209

#Unit 7. System Physiology – Animal

At birth, a large, well-nourished baby is found to have a plasma glucose concentration of 17 mg/Dl (normal is 80 to 100 mg/dL) and a plasma insulin concentration twice the normal value. What is the explanation for these findings?

TLS Online TPP Program

#Question id: 12210

#Unit 7. System Physiology – Animal

Which of the following stimulates the secretion of parathyroid hormone (PTH)?

TLS Online TPP Program

#Question id: 12211

#Unit 7. System Physiology – Animal

A 57-year-old man is admitted as an emergency for upper GI bleeding. Endoscopy reveals multiple ulcers in the duodenum. Serum gastrin levels are eight-fold higher compared to normal. Zollinger-Ellison syndrome (ZES, gastrinoma) is suspected. Administration of which of the following substances is useful in confirming the diagnosis?

TLS Online TPP Program

#Question id: 12212

#Unit 7. System Physiology – Animal

 A 71-year-old man with upper abdominal pain and blood in the stool takes NSAIDS for the pain and washes it down with whiskey. Pentagastrin administration produced lower than predicted levels of gastric acid secretion. Secretion of which of the following substances is most likely to be diminished in this patient with gastritis?