Question

Developmental Biology

1. The of the amphibian embryo is the “organizer”. is localized to the dorsal region of the amphibian and fish embryo and is a transcription factor that helps define that region. 3. In amphibians the pattern of cleavage is - 4. In fish the pattern of cleavage is 5. In amphibians the cortical cytoplasm of a newly fertilized egg rotates about 30° resulting in the appearance of a visible zone (in many species) between the animal and vegetal regions called the _is the state in which more than one sperm fertilizes an egg and results in aberrant development. 7. In sea urchins, sperm are activated by chemotactic peptides such as resact (species specific) and this results in a calcium spike in the sperm head that causes the sperm to swim _ the source. wave leads to the fusion of cortical 8. During fertilization of the sea urchin egg a _ granules with the membrane. Not all of these will be used in the above 8 questions. None will be used twice. A. discoidal meroblastic B. displaced radial holoblastic C. rotational holoblastic D. B-catenin E. calcium F. gray crescent G. away from H. dorsal blastopore lip 1. BMP J. toward K. sodium L. Wnts M. polyspermy

Answer 1

1.Dorsal blastopore lip

2. β-catenin

3. Rotational holoblastic

4. Discoidal meroblastic

5. Grey crescent

6. Polyspermy

7. Toward

8. Calcium