SG 10: Evolution Chap 22 & Immunity Chap 13 Flashcards
what does the theory of evolution state?
Evolution is the theory that proposes the gradual change of inherited characteristics of populations over generations. These changes give rise to diversity and allow for the gradual change of species and even the development of new species over time.
what is a theory?
is a well-substantiated and wide ranging explanation of some aspect of the physical world that is acquired through the scientific method, and repeatedly confirmed through observation and experimentation.
What is a Phylogenetic tree?
[represents species evolution] it is a branching diagram used by scientists to depict hypotheses about evolutionary relationships among species or group of species.
what are the problems with antibiotic resistance? how did it develop? and what causes it?
Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic. Antibiotic resistance evolves naturally via natural selection through random mutation, but it could also be engineered by applying an evolutionary stress on a population. Antibiotic resistance is a consequence of evolution via natural selection. They will then pass this trait to their offspring, which will be a fully resistant generation.
What is antibiotic resistance? Here is a simple example. If you get a strep throat and take penicillin for it, the penicillin will kill off most of the streptococcal (strep) bacteria. But a few strep bacteria might survive. These survivors are, for many different reasons, resistant to the medicine. The next time around, your strep throat might not respond to penicillin.
You can acquire drug-resistant bacteria in many different ways. They can come from overusing antibiotics, or taking them when they aren’t necessary, as for a viral infection. You can develop resistance to antibiotics by eating meat treated with antibiotics. It’s also possible to get an antibiotic-resistant infection from other people—even, unfortunately, from health care professionals.
Why is antibiotic resistance a problem? The major issue is that commonly used antibiotics will become less able to treat common infections. That means doctors must turn to more powerful and sometimes less friendly antibiotics, or may not have anything in their arsenal.
Antibiotic resistance occurs when an antibiotic has lost its ability to effectively control or kill bacterial growth; in other words, the bacteria are “resistant” and continue to multiply in the presence of therapeutic levels of an antibiotic.
natural selection?
*modern species are descendants of ancestral species. *some individuals have more surviving offspring than do others because their particular inherited characteristics make them better suited to their local environment. *the process whereby organisms better adapted to their environment tend to survive and produce more offspring.
What are the three lines of defense?
there are 3 strategies for defending against foreign organisms, molecules, or cancer cells. 1-Physical and chemical barriers 2-defensive cells & proteins, inflammation & fever 3-Adaptive Immune Response 1 & 2 we are born w/these 2 defense mechanisms. the 3rd is adaptive, specific mechanism of defense.
What is the first line of defense?
are physical(skin and mucous membrane) and chemical barriers. physical barriers such as skin prevents anything entering the body. Mucous traps microbes and prevents them from fully entering the body. we eliminate this mucous by sneezing, coughing or swallowing. Chemical barriers includes exocrine glands(sweat and oil) wash away microbes. slows bacterial growth and oil contains chem that kill some bacteria. the lining of the stomach produces hydrochloric acid and protein digesting enzymes that despry many pathogens, as well as viginas acidic environment, urines acidity, and saliva/tears contain lysozyme.
What is the second line of defense?
is when the body attacks any foreign organisms, molecules or cancer cells in the body by nonspecific internal cellular and chemical defenses that become active if the surface barriers are penetrated. includes defensive cells, inflammation, proteins and fever.
what are pathogens?
bacteria, viruses, protozoans, fungi, parasitic worms and prion(infectious proteins) that cause disease.
What is the third line of defense?
is the adaptive immune response which destroys specific targets(foreign organisms, molecules or cancer cells) and remembers those targets so that a quick response can be mounted if they enter the body again.
Be able to explain the process of inflammation
when the body tissues are injured or damaged, inflammatory reaction occurs. this response helps destroy invaders, repair and restore damaged tissue. redness: blood vessels dilate(widen) in the damaged area causing blood flow to increase which increases access of defensive cells. Heat: increased blood flow also elevates the temperature in the area of injury. heat increases the metabolic rate of the body cells in the region, speed up healing, and also increases the activities of phagocytes and other defensive cells. Swelling: fluids seep into the tissue from the bloodstream. blood clotting factors enter the injured area and begin to wall of the region Pain: is caused by excess fluids on tissue presses nerves, bacterial toxins. injured cells also release pain-causing chemicals.
What is the result of the release of histamine?
causes the widening of blood vessels, makes capillaries more permeable(leakier) . histamine is released by small mobile connective tissue cells called mast cells in response to chemicals from damaged cells.
What is the function of natural killer cells?
NK is a type of wbc that roams the body in search for abnormal cells and destroys them by releasing proteins that create pores in the target cell causing it to leak and burst. NK kill many invading organism and cancer cells.
What is phagocytosis and how does it help us against infection?
phagocytosis is the process in which phagocytes a wbc specialized “scavenger cells” engulfs pathogens, damaged tissue or dead cells. When a phagocyte encounters a foreign particle, cytoplasmic extensions flow from the cell, binds to the particle and pulls it inside. once inside, the particle is enclosed inside a vesicle and quickly destroyed by digestive enzymes. serves as the front line internal defense system and janitors that clean up debris. macrophages: big phagocytes that attack and consume virtually anything that doesn’t have MHC “self”
What is the function of major histocompatibility complex (MHC)?
this molecule serves as flag declaring the cell as “friends” Each cell in your body has special molecules embedded in the plasma membrane that labels the cell as self. the self labels are diff from anybody else. the immune system uses these labels to distinguish what is part of your body from what is not.
