Bacteria

Question 1

Ancestors of bacteria

Answer 1

The ancestors of our current bacteria were unicellular micro-organisms that were the first forms of life to develop on earth about 4 billion years ago

Question 2

General characteristics of bacteria

Answer 2

1. Most diverse and abundant group of organisms
2. Inhabit practically all environments
3. Mostly useful, some cause diseases
4. Vary in shape:
   - spherical bacteria called cocci
   - rod-shaped called bacilli
   - spiral shaped called spiralla
   - comma shaped called vibrios
5. Can exist singly or in clumps
6. In favourable conditions they reproduce rapidly by binary fusion
7. In unfavourable conditions, may survive by becoming dormant. They form spores with a thick protective coat around themselves
   5.

Question 3

Structure of bacteria

Answer 3

1. Bacteria are unicellular
2. Have a rigid cell wall
3. Plasma membrane serves many purposes: 1. Serves as a mitochondrion, endoplasmic reticulum and sometimes even a chloroplast. 2. It also controls the entry and exit of materials
4. Are prokaryotes: have no true nucleus, this is because they have no nuclear membrane
5. Closed loop of dna
6. Can have a waxy capsule as their outermost layer
7. Some have flagella which enables them to move