Biology Forums - Study Force

Diffusion, enzymatic degradation, and uptake by cells are all ways to
 
  a) remove a neurotransmitter
  b) stop a spatial summation
  c) continue a temporal summation
  d) inhibit a presynaptic potential
  e) excite a presynaptic potential

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(Question 2) A charged amino acid tends to decrease a protein's solubility in water.
 
  Indicate whether this statement is true or false.

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(Question 3) When a hormone is present in excessive levels, the number of target-cell receptors may decrease. This is called
 
  a) receptor recognition.
  b) sensory adaptation.
  c) paracrine regulation.
  d) up-regulation.
  e) down-regulation.

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(Question 4) Which gender shows the coccyx pointed inferiorly?
 
  a) Females
  b) Males
  c) Both genders
  d) The coccyx does not point inferiorly in either gender

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(Question 5) A protein consists of
 
  A. an amine group, a carboxyl group, and an R group.
  B. more than 200 amino acids.
  C. between 3 and 20 amino acids.
  D. a C-terminal, several nucleic acids, and an N-terminal

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(Question 6) In which type of synovial joint does a rounded or pointed surface on one bone articulate with a ring formed partly by another bone and partly by a ligament?
 
  a) Pivot joint
  b) Planar joint
  c) Hinge joint
  d) Ball-and-socket joint
  e) Saddle joint

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(Question 7) Describe the factors that lead to muscle fatigue.
 
  What will be an ideal response

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(Question 8) Which statement accurately describes amino acids?
 
  A.  There are twenty varieties, with each type having a different R group. B.  There are twenty varieties, with each type having a different C-terminal end. C.  There are over 200 varieties, with each type having a different R group. D.  There are over 200 varieties, with each type having a different C-terminal end.

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(Question 9) Which fingerlike projections found in the dural venous sinuses reabsorb cerebrospinal fluid?
 
  a) Choroid plexuses
  b) Microvilli
  c) Arachnoid villi
  d) Dural villi
  e) Lemnisci

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(Question 10) When dehydration synthesis occurs between two amino acids, a covalent bond called a _________ bond forms between them.
 
  Fill in the blank with correct word.

1) a

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2) FALSE

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3) e

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4) a

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5) B

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6) a

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7) Although the precise mechanisms that cause muscle fatigue are still not clear, several factors are thought to contribute. One is inadequate release of calcium ions from the SR, resulting in a decline of Ca2+ concentration in the sarcoplasm. Depletion of creatine phosphate also is associated with fatigue, but surprisingly, the ATP levels in fatigued muscle often are not much lower than those in resting muscle. Other factors that contribute to muscle fatigue include insufficient oxygen, depletion of glycogen and other nutrients, buildup of lactic acid and ADP, and failure of action potentials in the motor neuron to release enough acetylcholine.

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8) A

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9) c

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10) peptide