Which of the following statement is true regarding second level of organization 

a. The second level of organization is the coiling of the 10-nm fiber of nucleosomes into a helical array.

b. The coiled helical array to constitute the fiber of diameter 30 nm that is found in interphase chromatin and in mitotic chromosomes.

c. This compacts the DNA - 40-fold. The structure of this fiber requires the histone tails and is stabilized by linker histones.

d. Histone H1, histone tails, and increased ionic strength all promote the formation of the 30-nm fiber.

#Question id: 11018

#Unit 7. System Physiology – Animal

A 50-year-old man has a blood pressure of 140/85 and weighs 200 lb. He reports that he is not feeling well, his EKG has no P-waves, he has a heart rate of 46, and the QRS complexes occur regularly. What is his likely condition?

#Question id: 11019

#Unit 7. System Physiology – Animal

An 80-year-old man had an EKG taken at his local doctor’s office, and the diagnosis was atrial fibrillation. Which of the following statements are likely conditions in someone with atrial fibrillation?

#Question id: 11020

#Unit 7. System Physiology – Animal

Circus movements in the ventricle can lead to ventricular fibrillation. Which of the following conditions in the ventricular muscle will increase the tendency for circus movements?

#Question id: 11021

#Unit 7. System Physiology – Animal

A 75-year-old man goes to the hospital emergency department and faints. Five minutes later he is alert. An EKG shows 75 P waves per minute and 35 QRS waves per minute with a normal QRS width. Which of the following is the likely diagnosis?

#Question id: 11022

#Unit 7. System Physiology – Animal

A 55-year-old man had the following EKG recorded at his doctor’s office during a routine physical examination.

What is his diagnosis?

#Question id: 11023

#Unit 7. System Physiology – Animal

A male patient had a myocardial infarction at age 55. He is now 63 years old. Standard limb lead I is shown here.

What is his current diagnosis?