25. The rate equation for a reaction, A → B is r = k[A]" if the initial concentration of the reactant is a mol dm-3, the half period of the reaction is: k a a. b. a a k 2a a C. d. k 2k
Answers
Explanation:
1. Who discovered cell in 1665?
a) Robert Hook
b) Robert Crook
c) David Thomson
d) Marie Francois
Ans. a)
Explanation: In 1665, the cell was first discovered by Robert Hooke. The cell has a rich and interesting history that has ultimately provided the way to various scientific advancements of today.
2. Name an Organelle which serves as a primary packaging area for molecules that will be distributed throughout the cell?
a) Mitochondria
b) Plastids
c) Golgi apparatus
d) Vacuole
Ans. c)
Explanation: Golgi apparatus is also known as Golgi complex or Golgi body. It is an organelle that serves as a primary packaging area for molecules that will be distributed throughout the cell. It is located in the cytoplasm next to the endoplasmic reticulum and near the nucleus of the cell.
3. Name the outermost boundary of the cell?
a) Plasma membrane
b) Cytoplasm
c) Nuclear membrane
d) None of the above
Ans. a)
Explanation: Plasma Membrane is the outermost boundary of the cell. It is also known as the cell membrane. It is the membrane found in all cells that separate the interior of the cell from the outside environment. A cell wall is attached to the plasma membrane on its outside surface in bacterial and plant cells.
4. Name the process in which the ingestion of material by the cells is done through the plasma membrane?
a) Egestion
b) Diffusion
c) Osmosis
d) Endocytosis
Ans. d)
Explanation: Endocytosis is the process in which the ingestion of material by the cells is done through the plasma membrane. Or we can say that it is the process of actively transporting molecules into the cell by engulfing it with its membrane.
5. Which among the following sentence is not correct about the organelles?
a) They are found in all Eukaryotic cells.
b) They are found in multicellular organisms.
c) They coordinate to produce the cell.
d) They are small sized and mostly internal.
Ans. b)
Explanation: Organelles are found in all Eukaryotic cells. They coordinate to produce the cell. They are small-sized and mostly internal. Organelle, any of specialised structures inside a cell that perform a specific function (e.g. mitochondria, ribosomes, endoplasmic reticulum). Organelles in unicellular organisms are the equivalent of organs in multicellular organisms.
6. Name the process in which the passage of water goes from a region of higher concentration to a region of lower concentration through a semi permeable membrane?
a) Diffusion
b) Osmosis
c) Both a) and b)
d) Neither a) nor b)
Ans. b)
Explanation: Osmosis is the process in which the passage of water goes from a region of higher concentration to a region of lower concentration through a semi-permeable membrane.
7. Name an organism that contains a single chromosome and cell division occurs through fission or budding?
a) Eukaryotes
b) Prokaryotes
c) Bacteria
d) Primitive organism
Ans. b)
Explanation: Prokaryotes contain a single chromosome and cell division occurs through fission or budding. The usual method of prokaryote cell division is termed binary fission. The prokaryotic chromosome is a single DNA molecule that first replicates, then attaches each copy to a different part of the cell membrane.
8. Name the process in which the membrane of a vesicle can fuse with the plasma membrane and extrude its contents to the surrounding medium?
a) Exocytosis
b) Endocytosis
c) Osmosis
d) Diffusion
Ans. a)
Explanation: Exocytosis is the process in which the membrane of a vesicle can fuse with the plasma membrane and extrude its contents to the surrounding medium.
9. The jelly-like substance present inside the cell is known as:
a) Cytoplasm
b) Ectoplasm
c) Nucleoplasm
d) None of the above
Ans. a)
Explanation: Cytoplasm is the jelly-like substance present inside the cell and contains other organelles. It is a thick solution that fills each cell and is enclosed by the cell membrane.
10. Blue-green Algae are:
a) Prokaryotes
b) Eukaryotes
c) Both a) and b)
d) Neither a) nor b)
Ans. a)
Explanation: Blue-green Algae or Cyanobacteria are Prokaryotes. They lack membrane-bound organelles and nuclei.
Answer:
Reaction is A⟶B
Rate is given as r=k[A]
0
=k
Order of the reaction is 0.
Initial concentration of A is A
0
=a
Order of the reaction is zero.
Half-life, t
1/2
=
2k
[A
0
]
=
2k
a
Explanation: