![]()
Fig.1 Structure of a Bacterium. Capsule. - A rigid cell wall made of polysaccharides and amino acids. This provides protection although absent in some species. Cell wall- This contains a unique substance called peptidoglycan Cytoplasm - A fluid consisting of water, enzymes, nutrients, wastes, The structures such as ribosomes, a chromosome, and plasmids are embedded in this. Nucleoid- .This contains the genetic material without a a covering membrane. Pilli - These are protoplasmic protuberences which are sensitive and helps to adhere to a surface. Flagella - These help the cell to move usually in water.
Introduction Bacteria are the smallest independent living cells; probably made their first appearance long before any other living creature, These tiny specks of cytoplasm and DNA, wrapped up in a membrane, are capable of extremely complicated bio-chemical reactions, derive energy from the most unbelievable sources and tolerate extremely harsh conditions as in volcanic vents, hot springs and Arctic ice. Types of Bacteria According to shape bacteria are divided into three groups.
S
A few good bacteria.
A few Pathogenic Bacteria
Comparing Microbes
More about bacteria. If you wish to know about the natural enemies of bacteria click: Bacteriophages
1. 0 Name any 5 of the numbered parts. 2 x 5 = 10 2.0 1.Why do the scientists consider bacteria as
living things?
2.
This is a reason for not considering bacteria as
a plant. a.
Lack of cellulose. b.
Locomotion. C. Extra cellular
digestion. d. Lack of chloroplast. 3.
What is the normal way of nutrition in bacteria ? a.
Photo synthesis.
b. Respiration. c. Engulfing the food. d. Extra cellular digestion. 4.
Why are the bacteria grouped as procaryotes? a. Lack of organelles
.
b. Presence of cell wall. c.
Presence of DNA. d. Uni cellular. 5 x 4 = 20 marks. 2.0 Answers- 1. c, 2. d, 3. d. 4. a, 3.0 Complete this chart.
4x5= 20 marks 4.0 Give your verdict on the following statements.
5 x 10 = 50 For answers Click: Answer page. |
Biology >