SG 10: Evolution Chap 22 & Immunity Chap 13 Flashcards

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1
Q

what does the theory of evolution state?

A

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.

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2
Q

what is a theory?

A

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.

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3
Q

What is a Phylogenetic tree?

A

[represents species evolution] it is a branching diagram used by scientists to depict hypotheses about evolutionary relationships among species or group of species.

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4
Q

what are the problems with antibiotic resistance? how did it develop? and what causes it?

A

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.

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5
Q

natural selection?

A

*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.

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6
Q

What are the three lines of defense?

A

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.

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7
Q

What is the first line of defense?

A

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.

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8
Q

What is the second line of defense?

A

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.

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9
Q

what are pathogens?

A

bacteria, viruses, protozoans, fungi, parasitic worms and prion(infectious proteins) that cause disease.

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10
Q

What is the third line of defense?

A

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.

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11
Q

Be able to explain the process of inflammation

A

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.

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12
Q

What is the result of the release of histamine?

A

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.

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13
Q

What is the function of natural killer cells?

A

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.

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14
Q

What is phagocytosis and how does it help us against infection?

A

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”

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15
Q

What is the function of major histocompatibility complex (MHC)?

A

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.

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16
Q

What is an antigen?

A

is a non-self substance or organism that triggers an immune response. they lack MHC.

17
Q

What are lymphocytes? functions?

A

are certain WBCs that are responsible for both the specificity and the memory of the adaptive immune response. B & T cells. T cells develop the ability to distinguish cells that belong to the body, recognize the specific MHC self markers both cells are programmed to recognize one particular type of antigen. they each have their own particular receptors

18
Q

What is the structure of an antibody? What is it function? How does it work?

A

structure: y shaped proteins. function: neutralize and removes by many ways potential treats from the body. they are programmed to recognize and bind to the antigen posing the treat. *can only bind to antigens that are free in body fluids or attached to the surface of a cell. some cause the antigens to clump together and precipitate making it easier for phagocytes to engulf them, others pokes holes into the target cells, help attract phagocytes to the area, and also neutralizes them.

19
Q

In which tissue(s) are lymphocytes formed?

A

they both are formed in the bone marrow but mature in different organs. B in the bone marrow and T in the thymus gland

20
Q

What is clonal expansion and what triggers it?

A

production of daughter cells all arising originally from a single cell. In a clonal expansion of lymphocytes, all progeny share the same antigen specificity. this is triggered when an antigen fits into the lymphocytes receptors. the body defenses target that particular molecule.

21
Q

What are plasma cells and what are their functions?

A

plasma cells are the effectors of the antibody-mediated immune response. they secrete antibodies into the bloodstream specific to extracellular antigens such as toxins, bacteria, and free viruses. are split from the B cell.

22
Q

What is the function of effector cells? Memory cells?

A

both are descendants of T & B cells that had to divide repeatedly forming two lines of cells. effector cells: carry out the attack on the enemy, live only for a few days. Memory cells: are log-lived cells that “remember” that particular invader and mount a rapid response to it if it should appear again.

23
Q

What is the function of a cytotoxic T cell?

A

Are responsible for the cell-mediated immune response which protects against cellular pathogens or abnormal cells(viruses infected cells, cancerous cells.) cytotoxic T cells quickly destroy the cellular targets (pathogen/abnormal cells) by causing them to burst. when activated by the Helper T cells, the cytotoxic T cell divides to form the effector cytotoxic and memory cytotoxic T cells.

24
Q

what is the function of a Helper T cell?

A

the Helper T cell is the “on” switch for both lines of immune response( antibody-mediated and cell-mediated immune response.) After activation by macrophage, the helper T cell divides forming effector helper t cells and memory helper t cells.

25
Q

What is perforins?

A

perforins is a chemical released by the effector cytotoxic T cells which causes holes to form in the target cell membrane. the holes are large enough that causes the cell to disintegrate.

26
Q
  • What is an allergy?
A

an allergy is an overreaction by the immune system to an antigen. most common allergy is hay fever. and occurs when an allergen is inhaled triggering an immune response in the respiratory system.

27
Q

What is the principle behind vaccinations?

A

vaccination is a procedure that introduces a harmless form of an antigen into the body to stimulate adaptive immune responses against that antigen.

28
Q

What does it mean that a disease is an autoimmune disease? Know examples

A

Autoimmune diseases refer to problems with the acquired immune system’s reactions. In an autoimmune reaction, antibodies and immune cells target the body’s own healthy tissues by mistake, signaling the body to attack them. exp: Diabetes, type 1. A condition in which the immune system destroys insulin-producing cells of the pancreas, making it impossible for the body to use glucose (blood sugar) for energy. Type 1 diabetes usually occurs in children and young adults Rheumatoid arthritis. A disease in which the immune system attacks the linings of the joints. This results in joint pain, stiffness, swelling, and destruction. Vitiligo. A disorder in which the immune system destroys pigment-making cells called melanocytes. This results in white patches of skin on different parts of the body

29
Q

What is severe combined immunodeficiency?

A

SCID is actually a group of inherited disorders that cause severe abnormalities of the immune system. These disorders lead to reduced or malfunctioning T- and B-lymphocytes, the specialized white blood cells made in the bone marrow and the thymus gland to fight infection.

30
Q

What is AIDS? How does it affect the immune system?

A

AIDS is caused by the human immunodeficiency virus (HIV) and is spread through the exchange of body fluids. HIV INFECTION begins with a sharp rise of virus in the blood and a consequent drop in T helper cells . The immune system soon recovers somewhat, however, and keeps HIV levels fairly steady for several years. AIDS is diagnosed when the CD4 T cell level drops below 200 cells per cubic millimeter of blood or when opportunistic infections arise.

31
Q

What is the difference between being HIV positive and having AIDS?

A

When a person is infected with the human immunodeficiency virus (HIV) we say that he or she is “HIV positive,” or “has HIV.” A person who has HIV is classified as having AIDS if one of two things happens: 1.if the CD4 count has dropped below 200/cc, or 2.if an HIV-related infection or HIV-related cancer develops