02:01Gastrulation and Neurulation Animated I Embryology I Early EmbryogenesisThe Science Tutorials Channel1277views
06:34Stages of Animal Development: Cleavage, Gastrulation, OrganogenesisProfessor Dave Explains1378views
02:16Early embryogenesis - Cleavage, blastulation, gastrulation, and neurulation | MCAT | Khan Academykhanacademymedicine840views
Multiple ChoiceWhich of the following describes the correct sequence of stages during embryogenesis? 555views
Multiple ChoiceA sea urchin sperm penetrates the jelly coat of an egg and adheres to receptor proteins on the egg's surface as a result of __________. 601views1rank
Multiple ChoiceAfter a sperm penetrates an egg, a fertilization envelope forms. This envelope __________. 824views1rank
Multiple ChoiceThe period of repeated cell divisions without significant cell growth results in formation of the blastula and is called __________. 615views1rank
Multiple ChoiceHow is the animal hemisphere of a frog blastula different from the vegetal hemisphere? 1061views1rank
Multiple ChoiceAs an animal develops, organs form and the body transforms into a shape typical of the species in a process called __________. 429views
Multiple ChoicePeople with Kartagener's syndrome suffer from a variety of ailments, including the intriguing condition known as situs inversus, a reversal of the abdominal and thoracic organs. This condition occurs because of __________. 421views
Multiple ChoiceThe digits of a developing vertebrate limb respond to molecules that establish an anterior-posterior axis. These molecules originate in __________. 468views
Multiple ChoiceIn an experiment on eye development, a thin piece of aluminum foil was placed between the bulging wall of the brain and the overlying ectoderm where the eye normally forms. Wherever the foil was placed, the lens failed to develop because the foil __________. 395views
Multiple ChoiceUp to the eight-cell stage, the blastomeres of a mouse embryo can each form a complete embryo if isolated. This indicates that __________. 601views
Multiple ChoiceThe primitive streak of a bird embryo is the functional equivalent of the __________ in a frog. 567views
Multiple ChoiceOne difference between the blastula and gastrula stages of development is that __________. 718views
Multiple ChoiceWhich of the following extraembryonic membranes functions in gas exchange and encloses a chamber for the deposition of wastes of a bird embryo? 628views
Multiple ChoiceEvidence suggests that folic acid may help prevent the development of spina bifida, a common disabling birth defect. It is recommended that women increase their folic acid intake during pregnancy, especially in the first three months. Why is the timing of the folic acid intake relevant? 419views1rank
Multiple ChoiceIf you wanted to examine the extraembryonic membranes surrounding a lizard or mouse embryo, you would first have to cut through which of the following to see all the others? 421views
Multiple ChoiceWhich of the following correctly lists the embryonic stages in the order that they develop? 544views1rank
Textbook QuestionYou obtain an egg cell from the ovary of a white mouse and remove the nucleus from it. You then obtain a nucleus from a liver cell from an adult black mouse. You use the methods of nuclear transplantation to insert the nucleus into the empty egg. After some prompting, the new zygote divides into an early embryo, which you then implant into the uterus of a brown mouse. A few weeks later, a baby mouse is born. What color will it be? Why?512views
Textbook QuestionIn an experiment, a researcher colored a bit of tissue on the outside of a frog gastrula with an orange fluorescent dye. The embryo developed normally. When the tadpole was placed under an ultraviolet light, which of the following glowed bright orange? (Explain your answer.) a. the heart b. the pancreas c. the brain d. the stomach433views
Textbook QuestionIn an embryo, nerve cells grow out from the spinal cord and form connections with the muscles they will eventually control. What mechanisms described in this chapter might explain how these cells 'know' where to go and which cells to connect with?558views
Textbook QuestionAs a frog embryo develops, the neural tube forms from ectoderm along what will be the frog's back, directly above the notochord. To study this process, a researcher extracted a bit of notochord tissue and inserted it under the ectoderm where the frog's belly would normally develop. What can the researcher hope to learn from this experiment? Predict the possible outcomes. What experimental control would you suggest?760views
Textbook QuestionShould parents undergoing in vitro fertilization have the right to choose which embryos to implant based on genetic criteria, such as the presence or absence of disease-causing genes? Should they be able to choose based on the sex of the embryo? How could you distinguish acceptable from unacceptable criteria? Do you think such options should be legislated?459views