Outline the events that take place between exposure of the oocyte to spermatozoa and formation of the first blastomere pair
Powerful acrosomal hydrolases released from the sperm head create openings between adherent granulosa cells (the corona radiata) and penetrate the zona pellucida. A solitary sperm penetrates to the oocyte membrane to which it fuses, sending its nucleus into the oocyte. This is the moment of fertilization. This triggers maturation of the haploid maternal pronucleus, followed by development of the male pronucleus. These then fuse in the act of amphimixis, the true combining of maternal and paternal haploid chromosome sets to form a unique diploid set of 46 chromosomes. Spindle fibers organize the chromosomes on the metaphase plate after the nuclear envelopes break down. After mitosis is complete, cytokinesis takes place, dividing the original zygote into two daughter cells or pair of blastomeres. This takes more than 30 hours to complete.
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Parallel muscles exhibit great strength but little endurance.
Answer the following statement true (T) or false (F)
If agglutination occurs after a blood transfusion, it may indicate
A. there were no agglutinins (antibodies) in the recipient blood. B. the donor had type O blood. C. the wrong blood type was used. D. the recipient had type AB blood.
Two of the four globin chains in the hemoglobin molecule are called alpha chains and the other two are called ________________ chains
Fill in the blank with correct word.
Which of the following is attached to the medial side of the tympanic membrane?
A. Malleus B. Stapedius C. Tensor tympani D. Stapes E. Incus