Multiple Choice QuestionsWhich of the following organelles contain DNA?
(i) Mitochondria (ii) Chloroplasts (iii) Golgi bodies (iv) Ribosomes
(i) and (ii)
(ii) and (iii)
(i) only
(iv) only
Assertion: Mitochondria and chloroplasts have their own genome.
Reason: Endoplasmic reticulum and Golgi body are the cell organelles which have their own DNA.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.
What are Singer and Nicolson known for?
One-gene-one-enzyme hypothesis
Plasma membrane modifications
Fluid-mosaic model of plasma membrane
Structure of DNA
In a 50 gm living tissue, what would be the amount of water
15- 25 gm
25 - 30 gm
35- 45 gm
70- 90 gm
The outermost limiting layer of mycoplasma is made up of
cell wall
cell membrane
mucilaginous sheath
slime layer
Specific proteins responsible for the flow of materials and information into the cell are called
membrane receptors
carrier proteins
integral proteins
none of these
Assertion : Nucleus is the controlling centre of a cell.
Reason : Pores in the nuclear envelop regulate the flow of materials in and out of the nucleus.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Virchow
Hooke
Leeuwenhoek
Brown
A.
Virchow
Rudolf Virchow was the first to suggest that new cells are formed from the division of the pre-existing cells - "omnis-cellula-e-cellula" i.e. every cell is derived from a previous cell.
Robert Hooke was the first to coin the term "cell" for small structures in a piece of cork under a microscope. His observations were published in a book named Micrographia.
Leeuwenhoek was the first person to observe and describe microscopic organisms and living cell. He observed nucleus in RBC of salmon fish and used simple lens and observed nuclei and unicellular organisms including bacteria. In 1676, he described the bacteria and gave the term animalcules. His observations laid the foundations for the science of bacteriology and microbiology. Robert Brown ( 1831) described and named nucleus.
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