2.
BIOLOGICAL CLAssIfICAtIOn
Q. Classification of Aristotle
Ans – He classified them into 2 groups ~ with red blood
and without red blood.
Q. What are criteria for five kingdom classification?
Ans - > Mode of nutrition
Mode of reproduction
Cell wall
Body organisation
Phylogenetic relationship
Q. What are the four groups of bacteria?
Ans – Coccus – spherical
Bacillus – rod shaped.
Vibrium – comma shaped.
Spirilla -spiral
Q. What are the three groups of archaebacteria?
Ans- Hot springs – thermoacidophiles
Marshy area – methanogens
Extreme salty area – halophiles
Q. Define archaebacteria.
Ans – They live in most harsh habitats such as extreme
salty area, hot springs, marshy area. They have different
cell wall structure than others which helps them to
survive in extreme conditions. They are also primitive.
Q. Why are they able to survive in extreme conditions?
Ans – They have different cell wall structure.
Q. What are methanogens?
Ans – They are present in guts of several ruminant
animals such as cow and buffalo. They are responsible
for methane that is biogas present in the dung of these
animals.
Q. Give an account on different mode of reproduction in
bacteria.
Ans - > fission
Spores
Transfer of DNA from one to another it is a primitive
mode of reproduction.
Q. Define Eubacteria
Ans -They are also known as true bacteria, and they do
not survive in extreme conditions. They have rigid cell
wall and if they are motile, they have a flagellum.
Q. Give the characteristic of cyanobacteria.
Ans – They have chlorophyll a which is similar to green
plants and are photosynthetic autotrophs. The are
unicellular, colonial, or filamentous, fresh water or
marine or terrestrial algae.
Q. Define heterocyst.
Ans – Some organisms can fix atmospheric nitrogen in
specialised cells. e.g., Nostoc and anabaena
Q. What is chemosynthetic bacteria with a role.
Ans - > They oxidise inorganic substances such as
nitrates, nitrites, and ammonia.
Uses the released energy for their ATP production.
Recycle nutrients such as phosphorus, sulphur,
iron, and nitrogen.
Q. Define heterotrophic bacteria.
Ans > making curd from milk.
Production of antibiotics
Fixing nitrogen in legume roots
Most abundant in nature
Q. Name a few bacterial diseases.
Ans - > cholera > Typhoid > citrus canker
Q. Give an account on mycoplasma.
Ans - > A bacteria
Kingdom Monera
Lacks cell wall.
Survives without O2
Pathogens in plants and animals
Q. Define the general characterises of Protista.
Ans - > single celled eukaryotes
Chroysophytes
Dinoflagellates
Euglenoids
Slime mould
Protozoans
Some have flagella called cilia.
They reproduce sexually and asexually by cell
fusion and zygote formation.
nAME tHE fOLLOWInG
1. Parasitic ameboid – Endo amoeba
2. Sleeping sickness - Trypanosoma
3. Malarial parasite - Plasmodium
4. Red tide – Gonyalaux
5. Saprophytic Protista – Slime mould
Q. Write the feature of cell wall of cryophytes.
Ans - > 2 thin overlapping shells looking like a soap box.
Embedded with silica.
Walls are indestructible.
Q. Define diatomaceous earth and give its uses.
Ans – diatoms have left behind large amount of cell wall
deposits in their habitat. The uses are: -
Polishing
Filtration of oils and syrups
DInOfLAGELLAtEs
Habitats – mostly marine
Photosynthetic
Cell wall – stiff cellulose plates
Flagellates – longitudinally and transversally in a
furrow b/w wall plate
Red tides: -
~ Rapid multiplication they make the sea look red.
~Toxins are released by such large number which
may even kill other marine animals such as fishes.
Appearance – yellow, green, brown, or red
depending on the main pigments present in their
cells.
EUGLEnOIDs
Plant animals
Habitat – stagnant water
They have protein rich layer called pellicle which
makes their body flexible (it is instead of cell wall)
Flagella – short and long one
Pigmentation – identical to those present in higher
plants e.g.: euglena.
sLIME MOULDs
Saprophytic protists
Body moves along decaying twigs and leaves
engulfing organic material.
Favourable conditions - They form an aggregation
called plasmodium which may grow or spread over
several foots.
Unfavourable conditions – Plasmodium
differentiates and forms fruiting bodies bearing
spores at their tip
They are extremely resistant and survive for many
years.
The spores are dispersed under by air currents
