BIOLOGY HELP PLEASE!! 2. What is true of paramecia? A. They are …

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  • J Gen Physiol
  • v.55(4); 1970 Apr 1
  • PMC2203010
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J Gen Physiol. 1970 Apr 1; 55(4): 467–483.
PMCID: PMC2203010
PMID: 5435781

Passive Electrical Properties of Paramecium and Problems of Ciliary Coordination

Roger Eckert and Yutaka Naitoh
Author information Article notes Copyright and License information Disclaimer
From the Department of Zoology and the Brain Research Institute, University of California’ Los Angeles, California 90024
Received 1969 Oct 27
Copyright © 1970 by The Rockefeller University Press
This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at ).
This article has been cited by other articles in PMC.


Potential recordings made simultaneously from opposite ends of the cell indicate that the cytoplasmic compartment of P. caudatum is nearly isopotential. Measured decrements of the spread of steady-state potentials are in essential agreement with calculated decrements for a short cable model of similar dimensions and electrical constants. Action potentials and passively conducted pulses spread at rates of over 100 µm per msec. In contrast, metachronal waves of ciliary beat progress over the cell with velocities below 1 µm per msec. Thus, electrical activity conducted by the plasma membrane cannot account for the metachronism of ciliary beat. The electrical properties of Paramecium are responsible, however, for coordinating the reorientation of cilia (either beating or paralyzed by NiCl2) which occurs over the entire cell in response to current passed across the plasma membrane. In response to a depolarization the cilia assume an anteriorly directed orientation (“ciliary reversal” for backward locomotion). The cilia over the anterior half of the organism reverse more strongly and with shorter latency than the cilia of the posterior half. This was true regardless of the location of the polarizing electrode. Since the membrane potential was shown to be essentially uniform between both ends of the cell, the cilia of the anterior and posterior must possess different sensitivities to membrane potential.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Brokaw CJ. Bend propagation along flagella. Nature. 1966 Jan 8;209(5019):161–163. [ PubMed ]
  • Hodgkin AL. Evidence for electrical transmission in nerve: Part I. J Physiol. 1937 Jul 15;90(2):183–210. [ PMC free article ] [ PubMed ]
  • HODGKIN AL. Ionic movements and electrical activity in giant nerve fibres. Proc R Soc Lond B Biol Sci. 1958 Jan 1;148(930):1–37. [ PubMed ]
  • HODGKIN AL, HUXLEY AF. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. [ PMC free article ] [ PubMed ]
  • Kinosita H, Murakami A. Control of ciliary motion. Physiol Rev. 1967 Jan;47(1):53–82. [ PubMed ]
  • Naitoh Y. Reversal response elicited in nonbeating cilia of paramecium by membrane depolarizatin. Science. 1966 Nov 4;154(3749):660–662. [ PubMed ]
  • Naitoh Y. Control of the orientation of cilia by adenosinetriphosphate, calcium, and zinc in glycerol-extracted Paramecium caudatum. J Gen Physiol. 1969 May;53(5):517–529. [ PMC free article ] [ PubMed ]
  • Naitoh Y, Eckert R. Ionic mechanisms controlling behavioral responses of paramecium to mechanical stimulation. Science. 1969 May 23;164(3882):963–965. [ PubMed ]
  • Naitoh Y, Eckert R. Ciliary orientation: controlled by cell membrane or by intracellular fibrils? Science. 1969 Dec 26;166(3913):1633–1635. [ PubMed ]
  • Sleigh MA. The co-ordination and control of cilia. Symp Soc Exp Biol. 1966;20:11–31. [ PubMed ]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press


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23 terms

Leslie_Lackey TEACHER

Schoolnet Protists Review



Which is true about reproduction in both a euglena and a paramecium?
A. They divide vertically.
B. They produce gametes.
C. They conjugate.
D. They form spores.
A They divide vertically
A paramecium is an example of?
A. a single-celled organism.
B. multiple organisms.
C. an inorganic substance.
D. a group of cells.
A. A single -celled organism
An amoeba eats by surrounding its food with its body. How does a paramecium eat differently than an amoeba?
A .A paramecium captures food with a vacuole.
B. A paramecium sweeps food into its oral groove.
C. A paramecium makes its food using photosynthesis.
D. A paramecium secretes enzymes to break food down.
B. A paramecium sweeps food into its oral groove
Which is true about reproduction for both an amoeba and a paramecium?
A. Both can conjugate.
B. Neither can conjugate.
C. An amoeba can conjugate, but a paramecium cannot.
D. A paramecium can conjugate, but an amoeba cannot.
D. Paramecium can conjugate, but an amoeba cannot
Which characteristic does a paramecium have in common with volvox?
A. able to produce gametes
B. can perform photosynthesis
C. has an organelle for movement
D. lives as one of a colony of cells
C. has an organelle for movement
What is the primary way the amoeba is different from the sunflower?
A .The amoeba is made of one cell.
B. The amoeba has limited respiration.
C. The amoeba can produce its own food.
D. The amoeba has organs that work together to form systems.
A. The amoeba is made of one cell
Which structure is common to both a euglena and a paramecium?
A. cilia
B. eyespot
C. chloroplast
D. contractile vacuole
… D contractile vacuole
Which characteristic can an amoeba change that a paramecium cannot change?
A sex
B shape
B shape
Which organism is able to work together with other cells of its species?
A amoeba
B euglena
C paramecium
D volvox
D. Volvox
Which protist would you expect to have an absolute requirement for sunlight?
A volvox
B amoeba
C euglena
D paramecium
A. Volvox
Which life function is the same for an amoeba as for other freshwater protists?
A the method used to obtain nutrients and energy
B the process used to constantly remove excess water
C the method used to detect changes in their environment
D the process used to remove waste products from their cytoplasm
B. the process used to constantly remove excess water
Which structural characteristic is present in a paramecium that is not present in an amoeba?
A pellicle
B cell wall
C cytoplasm
D cytoskeleton
A pellicle
Which is true about reproduction in both a euglena and a paramecium?
A They divide vertically.
B They produce gametes.
C They conjugate.
D They form spores.
A They divide vertically.
Why doesn’t a paramecium need an eyespot?
A A paramecium does not live where there is light.
B A paramecium does not photosynthesize its own food.
C A paramecium lives in shallower water than a euglena.
D A paramecium uses cilia instead of a flagellum to move.
B A paramecium does not photosynthesize its own food.
Which characteristic is the most likely reason euglenas are not classified as algae?
A None of the euglena species form colonies.
B All euglena species use flagella for movement.
C Some euglena species are full-time heterotrophs.
D All euglena species have eyespots to detect light.
C Some euglena species are full-time heterotrophs.
Which protist is a bi-flagellate autotroph?
A amoeba
B euglena
C paramecium
D volvox
D volvox
In which way is the euglena different from the volvox cell?
A A euglena can respond to light.
B A euglena can live in fresh water.
C A euglena can regulate water intake.
D A euglena can only reproduce asexually.
D A euglena can only reproduce asexually.
A euglena is an example of a?

A plant and animal like protist

B animal like protist

C plant like protist

D neither plant or animal like protist

A plant and animal like protist
Which protists have flagella for movement?

A amoeba and paramecium

B euglena and volvox

C amoeba and paramecium

D euglena and volvox

B euglena and volvox
Which protists are heterotrophs? (can make their own food)
A paramecium and euglena

B volvox and euglena

C paramecium and amoeba

D volvox and paramecium

C paramecium and amoeba
Which protist(s) have eyespots to sense light?

A amoeba and volvox

B paramecium and volvox

C amoeba and euglena

D volvox and euglena

D volvox and euglena
A paramecium is considered a?

A animal like protist

B a plant like protist

C a plant and animal like protist

D none of these answers

animal like protist
Euglenas are capable of heterotrophic behavior. How does a euglena differ from an amoeba in the way it gathers food?
A A euglena takes food in through its gullet and deposits it into a food vacuole.
B A euglena attaches to the surface of its food and secretes enzymes to digest it.
C A euglena wraps around the food and gradually builds a cell membrane around it.
D A euglena sweeps food into its gullet and breaks it down with cellular contractions.
A A euglena takes food in through its gullet and deposits it into a food vacuole.
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