Login

Join for Free!
119292 members


Understanding Paramecium

About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.

Moderator: BioTeam

Understanding Paramecium

Postby bionewbie » Sat Mar 11, 2006 3:29 am

I know that Paramecium can go through conjugation which is a sexual process right ... so why does Paramecium have both sexual and asexual reproduction?

What are the advantages / disadvantages of conjugation in Paramecium?
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Postby Khaiy » Sat Mar 11, 2006 3:44 am

It's about adaptation. Asexual reproduction means that a paramecium that is already well adapted to its environment will be able to produce more well-suited individuals, without risking taking on new alleles for less well adapted traits.

However, conjugation allows for one paramecium to take on a plasmid (genetic segment) from another paramecium. This way, if one has a beneficial trait, that trait can move through the population more quickly, as well as combining with paramecia that may have another well adapted trait.

This is seen in bacteria once antibiotics have been introduced. If one bacterium is resistant, then conjugation can allow for more resistant organisms to be produced quickly, allowing for a resistant colony to be established.
User avatar
Khaiy
Coral
Coral
 
Posts: 158
Joined: Tue Feb 28, 2006 2:37 am

Postby bionewbie » Sat Mar 11, 2006 4:24 am

But asexual reproduction is more common in Paramecium, right?

Does that have anything to do with how quickly it moves? I mean if there is less chances for the Paramecium to find other Paramecium to undergo conjugation, then it will just go through asexual reproduction. Does that make sense?
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm


Postby Ken Ramos » Sat Mar 11, 2006 11:12 am

It seems that Khaiy is well versed in this subject, so I will not make any rash statements. :lol: But I read somewhere that conjugation occurs only when the paramecium is in a stressed environment. So I am assuming that if conjugation did not occur, asexual reproduction would also cease and the colony of paramecia would soon die out. :(

BTW Khaiy, I enjoyed your answer to this question posed by bionewbe, quite interesting. :D
Ken Ramos, Aviation Ordnanceman USN Ret.
Western North Carolina
"If you see an explosives handler running...try to keep up with him!"
Ken's Nature Study
Ken Ramos
Viper
Viper
 
Posts: 115
Joined: Mon May 23, 2005 10:30 am
Location: Western North Carolina

Postby Poison » Sat Mar 11, 2006 6:12 pm

A general thing: If you can survive with your present genetic material, (considering that paramecium do not fall in love :lol:( kidding) ) why would you need a partner to produce new offsprings?
Logical isn't it? :)
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.
User avatar
Poison
Inland Taipan
Inland Taipan
 
Posts: 2322
Joined: Sun Jan 02, 2005 12:44 pm
Location: Turkey

Postby Ken Ramos » Sat Mar 11, 2006 7:43 pm

Poison asked:
A general thing: If you can survive with your present genetic material, why would you need a partner to produce new offsprings?


If I understand Khaiy right, say the parameciums environment has changed to a point to where its continued existance is questionable. Lets call this paramecium (A) Another paramecium which we will call (B) has the genetic make up to much better survive in the changing environment. By (A) conjugating or mating with (B) the exchange of genetic material which (B) has, is transfered to (A) across the cytoplasmic bridge, which is usually at or near the oral groove during conjugation. With (A) now having acquired this genetic material it can now go on to reproduce via binary fission to produce off spring which are now more adapted to the changing environment. However Jahn in his book, "How to Know the Protozoa," states under the Family Parameciidae, page 235; "the paramecium-groups are separated into species on the basis of paired mating types and certain minor, but constant, morphological and physiological traits." So, both (A) and (B) must be of the same group, of which there are nine groups of species. For example say both (A) and (B) are of the P. aurelia-group. They, (A) and (B) cannot conjugate with those belonging to say the bursaria-group. Now would I be correct in the above statement Khaiy? :roll:

My apologies for the quality of this image. It is an old one from my archives prior to up grading my photographic system. Pls. click on image for a larger view. Thanks. :D
Attachments
Paramecium, conjugation (F).JPG
Paramecia of the same group in the process of conjugation, 200X
(60.46 KiB) Downloaded 120 times
Ken Ramos, Aviation Ordnanceman USN Ret.
Western North Carolina
"If you see an explosives handler running...try to keep up with him!"
Ken's Nature Study
Ken Ramos
Viper
Viper
 
Posts: 115
Joined: Mon May 23, 2005 10:30 am
Location: Western North Carolina

Postby Khaiy » Sat Mar 11, 2006 9:50 pm

Yes, that's right. It's about being able to have more organisms producing offspring that are most fit to survive. Good work with your explanation, you described the process very accurately and clearly.
User avatar
Khaiy
Coral
Coral
 
Posts: 158
Joined: Tue Feb 28, 2006 2:37 am

Postby bionewbie » Sat Mar 11, 2006 10:40 pm

Ken Ramos wrote: My apologies for the quality of this image. It is an old one from my archives prior to up grading my photographic system. Pls. click on image for a larger view. Thanks. :D


I notice that the cilia that surrounds the Paramecium. This may sound like a stupid question but will cilia always be visible on a prepared Paramecium? (or does it depend on the type of imaging device that you use?)
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Postby Ken Ramos » Sun Mar 12, 2006 12:11 am

Khaiy replied:
Yes, that's right. It's about being able to have more organisms producing offspring that are most fit to survive. Good work with your explanation, you described the process very accurately and clearly.


Thanks Khaiy :D I had never considered what you had stated in your first response to the question and the statement about how bacteria can become resistant to antibiotics was most interesting. I learned something today Khaiy, thanks again! :D

bionewbe relies:
I notice that the cilia that surrounds the Paramecium. This may sound like a stupid question but will cilia always be visible on a prepared Paramecium? (or does it depend on the type of imaging device that you use?)


I am not familiar with the technique of mounting specimens, especially protozoa but I will go out on a limb and say that yes the cilia should be visible in a well prepared mount of the paramecium. You are correct also in considering the instrument with which the specimen is viewed through. Most student microscopes will show the cilia to an extent, some quite well even but the image quality does depend too on the quality of the instrument being used. At one time I used a Swift 3500D student microscope for the study of protozoa and its optical system performed quite well but not near as good as the Zeiss Axiostar Plus which I am using now. :D

BTW, do not let anyone ever tell you that asking a question is "stupid." There is no such thing as a "stupid question." In the field of science and the studies it encompasses, the only stupid questions are those not asked. :wink:

The following image was taken employing the Axiostar Plus, oblique illumination was used in obtaining the resulting contrast of the paramecium. Notice that the arrows in the upper section of the photograph point to the cilia as they appear on the surface of the pellical and the bottom arrow points the the cilia as they appear around the edges. The entire body or cell is covered with cilia and this lighting technique helps to show those that do not appear around the edges of the cell wall. This photograph was taken of live specimens, not a prepared slide. :D

Click on Image for Larger View! :o
Attachments
A00019 Paramecium.jpg
Paramecium _at_ 400X
Sony DSC P-200 _at_ 7mgp
1/50 sec. _at_ f/2.8 ISO 100
Zeiss Axiostar Plus
Oblique Halogen illumination w/18mm darkfield stop off center
(62.15 KiB) Downloaded 160 times
Ken Ramos, Aviation Ordnanceman USN Ret.
Western North Carolina
"If you see an explosives handler running...try to keep up with him!"
Ken's Nature Study
Ken Ramos
Viper
Viper
 
Posts: 115
Joined: Mon May 23, 2005 10:30 am
Location: Western North Carolina

Postby bionewbie » Sun Mar 12, 2006 4:23 am

As noted before, the cilia in the paramecium completely surrounds the organism, but there are other ciliates that have cilias localized at one end of the organism like the Vorticella. So what could be the advantage of that, knowing that Vorticella also has a contractile stalk?
Last edited by bionewbie on Sun Mar 12, 2006 8:27 pm, edited 1 time in total.
I would feel more optimistic about a bright future for man if he spent less time proving that he can outwit nature and more time tasting her sweetness and respecting her seniority. ~ E. B. White
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Postby Ken Ramos » Sun Mar 12, 2006 12:50 pm

When it comes to advantages or disadvantages I am not sure that there are any in natures design. However odd and cruel they may seem there is a purpose for that particular design. There are some who may debate that statement but everyone has a right to their own thoughts on the matter. :wink:

As for the Vorticella, the localized cilia are used primarily for feeding, Vorticella is a filter feeder. Although sessile, Vorticella can become free-swimming by breaking away from its stalk and using its cilia to swim. At this the Vorticella is now in a stage known as being a "telotroch." Not only does it use the cilia that is normally seen around the anterior of the organism but it will oftentimes form a ciliary band around the posterior of the lorica, just above where the stalk is attached and utilize this band of cilia for swimming also but note that this ciliary band is only seen prior to the detachment from the stalk as the "telotroch" stage is developing. Later this band of cilia will disappear. This is an amazing process to observe utilizing the microscope. :D

Among the Class Peritrichea with its Orders, Suborders and Families, the Vorticella has to be my favorite to photograph and to sit and just observe. It is also possible that one may confuse Vorticella with the Family Epistylididae, this family has loricates in a colony, whereas Vorticella exists independantly on a single stalk. :D
Ken Ramos, Aviation Ordnanceman USN Ret.
Western North Carolina
"If you see an explosives handler running...try to keep up with him!"
Ken's Nature Study
Ken Ramos
Viper
Viper
 
Posts: 115
Joined: Mon May 23, 2005 10:30 am
Location: Western North Carolina

Postby bionewbie » Sun Mar 12, 2006 8:26 pm

You wouldn't happen to have a picture of a Vorticella, do you? :D
I would feel more optimistic about a bright future for man if he spent less time proving that he can outwit nature and more time tasting her sweetness and respecting her seniority. ~ E. B. White
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Next

Return to Microbiology

Who is online

Users browsing this forum: No registered users and 1 guest