1. Give reasons for the following:
(a) Lysosomes are called suicide bags of the cell.
(b) Cell is known as structural and functional unit of life.
(c) Cells differ in size and shape.
(d) Mitochondria are called the powerhouse of the cell.
(e) Prokaryotes have simpler cell organisation
Answers
Answer:
a) Lysosome contain hydrolytic enzymes like proteases lipases, hydrolases that aids cellular digestion. But on attack from a pathogen, they rupture and release the chemicals to kill both the cell and the pathogen. Hence suicidal bags
b) All basic requirements for a simplest living organism is carried out by a cell. Cell is capable of independent existence, because it carries out its own metabolic patterns, respiration, and cell division too.
c) Cells differentiate from the blastocyst stem cells. They evolve in the way they are a part of. Example, stomach cells secrete HCl, but they contain genes for Thyroxin too but non functional. Similarly Alveolar cells are flattened epithelial, mucosa cells, guard cells, ciliated tube cells.
d) Mitochondria are the site of ATP synthesis. They possess the F⁰-F¹ channel for the transport of proton through proton gradient in the lumen. This energy in one pump is utilized to fix Adenosine Diphosphate + Inorganic P to ATP.
e) Prokaryotes are the most primitive life structure on Earth. They formed from protibionts, self replicating naked genetic sequence, and surrounded a cell membrane. They were the first to protect their genetic material from external environment. However they don't have most stable structures, even they are about 100 times smaller than typical cell.