A teenaged boy with numerous nosebleeds was referred to a physician for evaluation prior to a minor surgery. His prothrombin time (PT) was 11 sec (11–15 sec normal), partial thromboplastin time (PTT) was 58 sec (25–40 sec normal), and bleeding time was 6.5 min (2–7 min normal). Which of the following is most likely abnormal in this young man?

#Question id: 7279

#Unit 5. Developmental Biology

X chromosome number alone is the primary sex determinant in normal drosophila because:

#Question id: 7278

#Unit 5. Developmental Biology

The following demonstrates the blastocoel formation in the mammals. Which of the following statement is correct?

#Question id: 7277

#Unit 5. Developmental Biology

According to this model, Which of the following statements are correct?

#Question id: 7276

#Unit 5. Developmental Biology

The cells that make up a tetrapod limb arise from three developing tissues:

The ____a______ will provide skeletal precursors to the limb.

The _____b____ will provide muscle precursors to the limb.

The _____c____ will provide the skin of the limb.

Which of the following option is correct?

#Question id: 7275

#Unit 5. Developmental Biology

The following experiment is designed to study the role of several hormones in the regulation of metamorphosis in frogs.

If the thyroid gland were removed from the tadpoles in Group 4, metamorphosis would

#Question id: 7274

#Unit 5. Developmental Biology

The following experiment is designed to study the role of several hormones in the regulation of metamorphosis in frogs.

 If the thyroid gland were removed from the tadpoles in Group 3, metamorphosis would