MCQ
Who stated that virus are crystelline ?
  • A
    Beijernek
  • B
    Ivanowsky
  • C
    Diener
  • Stanley

Answer

Correct option: D.
Stanley
d

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In a pond ecosystem, benthos means
An alga which can be employed as food for human being is
Which of the following statements are incorrect ?
(i) Watson and Crick along with Wilkins and Franklin got the Nobel Prize for his work in 1962.
(ii) In RNA, every nucleotide residue has an additional-OH group present at 3'-position in the ribose.
(iii) 5-methyl uracil is an another chemical name for Thymine.
(iv) DNA as an acidic substance present in nucleus was first identified by Friedrich Meischer in 1869 and called it "Nuclein".
(v) In 1953 Watson and Crick, proposed double helix model for the structure of DNA.
(vi) Watson and Crick model is based on the X-ray diffraction data produced by Wilkins and Franklin.
(vii) According to Chargaff the ratio between Adenine and Guanine, Thymine and Cytosine are constant and equals to 1.
Which of the following is the smallest living cell and can live without oxygen?
Respiration occurs
Assertion : If pollen mother cells has $42$ chromosomes, the pollen has only $21$ chromosomes.
Reason : Pollens are formed after meiosis in pollen mother cell.
Characteristic of meristematic region of root
How many sentence are correct?

$(1)$ The trophic levels in $GFC$ are unlimited

$(2)$ Organisms at each trophic level depend on those at the higher trophic level for their energy demands.

$(3)$ Plants capture only $2 -10$ percent of $PAR$.

$(4)$ All organisms are dependent for their food on producers, either directly or indirectly.

$I.$ Initial $CO _{2}$ acceptor     $II.$ Extent of photorespiration

$III.$ Enzyme catalyzing reaction that fixes $CO _{2}$    $IV.$ Presence of Calvin cycle

$V.$ Leaf anatomy

Which one does not differ in a $C_{3}$ and $C_{4}$-plants?

Many tribes live in the high altitude of Himalayas in them