Tell how a carcinogen can cause cancer, and describe the progression of cancer
Some carcinogens directly cause rapid cell division and others are mutagens that may mutate a gene that regulates cell growth, differentiation, or division. Cancer begins with increased cell division to produce a cluster of cells called a tumor or neoplasm. These cells change their appearance, lose their response to certain inhibitory signals, and may acquire other mutations. Malignancy occurs as cells from the tumor invade surrounding tissues. Metastasis occurs when these cells enter the circulatory system and start tumors in distant regions of the body. Angiogenesis is the growth of blood vessels into the region of the tumor. Tumors can disrupt normal function by failing to carry out their regular functions, physically interfering with normal tissue, outcompeting normal tissues for nutrients, or overproducing their normal products, such as hormones.
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The transport of protons from the intermembrane space to the mitochondrial matrix occurs via ________.
A. ATP synthase B. lactate dehydrogenase C. transaminase D. FADH-coenzyme Q reductase complex
During a sinus infection it is difficult to smell because
A) basal cell division decreases. B) olfactory glands stop producing mucus. C) olfactory supporting cells block odorant molecules from reaching the receptors. D) the hypothalamus stops responding to olfactory stimulation. E) excess mucus blocks odorant molecules from reaching the receptors.
The most common type of cartilage, named for its glassy appearance, is
A. fibrocartilage. B. hyaline cartilage. C. elastic cartilage. D. reticular cartilage. E. areolar cartilage.
The membrane proteins that are sensitive to extracellular materials are called
A) receptor proteins. B) channel proteins. C) carrier proteins. D) anchor proteins. E) identifier proteins.