BiologyMarch29th2007 - outer layer of cells and a group of...

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Dustin Lee 33.3: Q1-3 Block C: Biology 1. Numerous mitochondria provide energy to move the tail, enabling the sperm cell to “swim” through the female reproductive system. Enzymes in the acrosome enable the sperm to penetrate the protective coats of the oocyte. 2. By about 36 hours after fertilization, a process called cleavage has begun ,during which the zygote undergoes a series of rapid mitotic divisions. By about the fifth day, cleavage has produced a ball of about 100 cells that has reached the uterus with the help of cilia in the oviduct. This ball of cells is called a blastocyst, a fluid-filled sphere consisting of an
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Unformatted text preview: outer layer of cells and a group of cells inside the sphere. 3. Fraternal are the result of more than one egg being fertilized during an ovarian cycle. For this to happen, both ovaries must release an egg, or one ovary must release two eggs. Each zygote of fraternal twins and supertwins is formed from a different egg and sperm. As a result, the genetic information for fraternal twins is different for each individual, in the same way that brothers and sisters born at different times have different genetic materials....
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This note was uploaded on 09/21/2011 for the course BIOG 1110 taught by Professor Randywayne during the Spring '09 term at Cornell University (Engineering School).

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