IMPORTANT POINTS:   

  • Diatoms are the chief producers in the oceans.
  • In bacteria the ribosomes are present singly or in small groups called POLYRIBOSOMES.
  • Cell wall of bacteria contain acetyl glucosamine, acetyl muramic acid, & a peptide chain of four or five amino acids. All these chemicals together form a polymer called PEPTIDOGLYCAN.
  • Transduction was discovered by Zinder & Lederberg in 1952 in Salmonella typhimurium
  • Mycoplasmas are smallest free living organism discovered by E.Nocard & E.R.Roux from pleural fluids of cattle suffering from bovin pleuropneumonia & named them as pleuropneumonia like organisms or PPLO. They were named mycoplasmas by Nowak in 1929. Mycoplasmas can survive without oxygen.

MCQ ON BIOLOGICAL CLASSIFICATION 3 24JUNE2024

 
QUIZ START

Results

well done .

Try again best of luck

#1. “Jokers of the plant kingdom” are

Mycoplasmas because they do not have a definite shape.

#2. Cell wall is absent in

Mycoplasmas

#3. Which of the following are found in extreme saline conditions

Archaebacteria are the primitive prokaryotic cells found in harsh conditions also. They are of three types :

  1. Methanogens : Strictest anaerobes live in swamps, marshes and in the gut of animals .Ex. Methanisarcina ,Methanobacillus , Methanococcus.
  2. Halophiles : Occur in extreme saline environment. Ex. Halobacterium , Halococcus
  3. Thermoacidophiles :Occur in hot & acidic conditions such as in hot sulphur springs at 80°C & PH 2 Ex. Sulfobolus, Thermoplasma, Thermoproteus

#4. Viroids have

Nucleic acid. Viroids are infectious particles having nuclear acid that is a free RNA. Viruses having protein coat enclosing nucleoid.

#5. Heterocyst are present in

Cyanobacteria :

Heterocyst : Special cells in Cyanobacteria like Nostoc , Anabaena ,Scytonema to perform special functions . They are the site of nitrogen fixation they have thick cell wall and lack nucleoid.

#6. Choose the correct option

All of the above.

#7. Oldest living fossils are

Archaebacteria

#8. Pollution indicator are

Lichens. Symbiotic relationship between fungus and algae form a structure called Lichens. Fungal partner is known as  mycobiont and Algal partner as phycobiont.

#9. Cell wall of bacteria is made up of

Peptidoglycan

#10. Red tide is caused by

All of the above. These all are dinoflagellates.

Previous
Finish

Leave a Comment

Your email address will not be published. Required fields are marked *