AP Bio homework quiz #1- animal form and function
is it accurate to define homeostasis as a constant internal environment
No, an animals internal environment fluctuates within a normal range or around set points
great diversity of B and T cells produced
V and J gene segments of light and heavy chain allele
dendtric cells
WBC located in the skin that move to lymph nodes and stimulate adaptive immunity
eosinophils
WBC that attack parasitic worms with enzymes
natural killer cells
WBC that attack the bodes infected or cancerous cells
clonal selection
antigen receptor binds to antigen, then the selected cell divides into a clone of effector cells and memory cells specific for that antigen
what substances remain in the capillaries
blood cells, large molecules such as plasma proteins
histamine
causes vasodilation and increased permeability of blood vessels
immunological memory
enhanced response to previously encountered foreign molecule
lysozyme
enzyme that attacks bacterial cell walls, found in tears, saliva mucus
function of filtration step in excretory systems
filtration produces a fluid for exchange process that is free of cells and large molecules, benefits the animal because otherwise they could not be readily absorbed
if a child were born without a thymus what cells and functions would they be deficient in
have no functional T cells, unable to produce antibodies against extracellular bacteria, childs immune system would be unable to kill viruses
endocrine system
hormones are released and travel more slowly, signals last longer, mediate responses, coordinates gradual function
what advantage does uric acid offer was a nitrogenous waste in arid environments
insoluble in water, excreted as a semi solid paste, reduces animals water loss
macrophages
large phagocytes that engulf microbes
explain to advantages of having memory cells when a pathogen is encountered for a second time
memory cells ensure that both a receptor specific for a particular epitope will be present and there will be more lymphocytes in the host than as encountered before by the pathogen
nervous system
nerve impulses are faster and travel quicker, shorter responses, regulates rapid response (behavior)
neutrophils
phagocytic white blood cells
interferons
proteins released by by virus-infected cells that stimulate neighboring cells to produce substances that inhibit viral replication
mast cells
release histamine to initiate inflammatory response
cytokines
set of blood proteins that cause lysis of microbes and are involved with innate and adaptive defenses
complement system
signaling proteins that enhance an immune response and promote blood flow to injury response
positive feedback
stimulus is reinforced (childbirth)
what prevents B and T cells from reacting against the bodys own molecules
tested for self reactivity, if its wrong, they will self destruct
negative feedback
try to get body back to original state (throwing up)
what substances are removed from blood during filtration
water, salts, nitrogenous wastes, glucose, vitamins, other small molecules