Neurofibromatosis, a benign tumor of the sheath cells that surround nerves, is caused by

a.  Loss of both alleles of NF1

b.  Mutation in RAS GAP-type protein

c.  A single mutant NF1 allele

d.  Mutation in SRC protein

#Question id: 10956

#Unit 7. System Physiology – Animal

The coagulation pathway that begins with tissue thromboplastin is

#Question id: 10931

#Unit 7. System Physiology – Animal

A 24-year-old African-American man comes to the emergency room 3 hr after the onset of severe back and chest pain. These problems started while he was skiing. He lives in Los Angeles and had a previous episode of these symptoms 5 years ago while visiting Wyoming. He is in obvious pain. Laboratory studies show the following:

Hemoglobin                                        11 gm/dl

Leukocyte count                                 22,000/μl3

Reticulocyte count                              25%

What is the diagnosis of this patient?

#Question id: 10929

#Unit 7. System Physiology – Animal

Which of the following would describe the condition in a patient with aplastic anemia?

Which of the following is correct?

#Question id: 5687

#Unit 8. Inheritance Biology

The error in meiosis that produces a 47,XYY karyotype is best  described by

#Question id: 5688

#Unit 8. Inheritance Biology

Which of the following are not cause of aneuploidy

#Question id: 5690

#Unit 8. Inheritance Biology

Species I is diploid (2n =4) with chromosomes AABB; related species II is diploid (2n = 6) with chromosomes MMNNOO .Which of the following chromosome  in allotriploid individuals?