1. Tardigrade
  2. Question
  3. Biology
  4. Consider the following statements. (a) Plant cells have centrioles which are absent in almost all animal cells (b) Ribosomes are the site of protein synthesis (c) The middle lamella is the layer mainly of calcium carbonate which holds the different neighbouring cells together (d) In animal cells steroidal hormones are synthesised by smooth endoplasmic reticulum. Of the above statements :

Q. Consider the following statements.
(a) Plant cells have centrioles which are absent in almost all animal cells
(b) Ribosomes are the site of protein synthesis
(c) The middle lamella is the layer mainly of calcium carbonate which holds the different neighbouring cells together
(d) In animal cells steroidal hormones are synthesised by smooth endoplasmic reticulum.
Of the above statements :

 2340  211 KEAMKEAM 2010Cell : The Unit of Life Report Error

Solution:

The centrioles occur in nearly all animal cells and in motile plant cells, such as zoospores of algae, sperm cells of ferns, and motile algae. They are absent in amoeba, prokaryotic cells, higher gymnosperms and all angiosperms. Middle lamella is a thin, amorphous and cementing layer between two adjacent cells. It is made up of pectates of calcium and magnesium.