Cell : The Unit of Life

Select the correct statements out of the four (1-4) given below about lac operon.

• Glucose or galactose may bind with the repressor and inactivate it

• In the absence of lactose, the repressor binds with the operator region

• The z- gene codes for permease

• The z- gene codes for permease

The main arean of various types of activities of a cell is

• Plasma membrane

• mitochondrion

• cytoplasm

• cytoplasm

The plasma membrane consist mainly of 

• phospholipids embedded in a protein bilayer

• Proteins embedded in a phospholipid bilayer

• proteins embedded in a polymer of glucose molecules

• proteins embedded in a polymer of glucose molecules

If for some reason the parietal cells of the gut epithelium become partially non-functional, what is likely to happen?

• The pancreatic enzymes and specially the trypsin and lipase will not work efficiently

• The pH of stomach will fall abruptly

• Steapsin will be more effective

• Steapsin will be more effective

An elaborate network of filamentous proteinaceous structures present in the cytoplasm which helps in the maintenance of cell shape is called

• thylakoid

• endoplasmic reticulum

• plasmalemma

• plasmalemma

Identify the components labelled A, B, C and D in the diagram below from the list 1 to 8 given along with


1) Cristae of mitochondria
2) Inner membrane of mitochondria
3) Cytoplasm
4) Smooth endoplasmic reticulum
5) Rough endoplasmic reticulum
6) Mitochondrial matrix
7) cell vacuole
8) Nucleus

• A	B	C	D
  5	4	8	3

• A	B	C	D
  1	4	8	6

• A	B	C	D
  6	5	4	7

• A	B	C	D
  6	5	4	7

Middle lamella is mainly composed of 

• hemicellulose

• muramic acid

• calcium pectate

• calcium pectate

Plasmodesmata are

• lignified cemented layers between cells

• locomotory structures

• membranes connecting the nucleus with the plasmalemma

• membranes connecting the nucleus with the plasmalemma

Cytoskeleton is made up of 

• calcium carbonate granules

• callose deposits

• cellulosic microfibrils

• cellulosic microfibrils

Given below is a schematic break-up of the phase/stages of cell cycle



Which one of the following is the correct indication of the stage/phase in the cell cycle?

• B -Metaphase

• C-karyokinesis

• D-Synthetic phase

• D-Synthetic phase