Biological Classification

Question 1

Who was the first one to attempt biological classification?

Answer 1

Aristotle

Question 2

What did Linnaeus propose?

Answer 2

Two kingdom classification systems - plantar and animalia.

Question 3

Who proposed the five kingdom classification?

Answer 3

R. H. Whittaker in 1969

Question 4

What is the five kingdom classification?

Answer 4

Monera, protista, fungi, plantae and animalia

Question 5

How was monera further classified?

Answer 5

Three domain system divided Monera into two domains, leaving the remaining to third domain thus forming a six kingdom classification.

Question 6

Which organisms were grouped under Monera and protista?

Answer 6

All prokaryotic organisms under Monera and unicellular eukaryotic organisms under protista

Question 7

Who are the sole members of the kingdom Monera?

Answer 7

Bacteria

Question 8

What are the 4 categories of bacteria?

Answer 8

Cocci (spherical coccus)
Bacilli (rod shaped bacillus)
Vibrio (comma shaped vibrium)
Spirilla (spiral spirillum)

Question 9

What are the two types of bacteria?

Answer 9

Archaebacteria
Eubacteria

Question 10

Where are archaebacteria found?

Answer 10

In harsh habitats
Halophils - extreme salty areas
Thermoacidophils - hot springs
Methanogens - marshy areas

Question 11

Where are methanogens also found?

Answer 11

They are found in the gut of ruminant animals like cows and responsible for the production of methane from dung.

Question 12

What are eubacteria?

Answer 12

They are true bacteria characterised by the presence of rigid cell walls.

Question 13

What are cyanobacteria?

Answer 13

Blue green algae that have chlorophyll a and are photosynthetic autotrophs

Question 14

What is the structure of cyanobacteria?

Answer 14

They are unicellular, colonial or filamentous and found in fresh water, marine or terrestrial. Colonies are surrounded by gelatinous sheath and it blooms in polluted water bodies

Question 15

What is heterocyst?

Answer 15

Specialised cells that fix atmospheric nitrogen. Eg : nostoc, anabaena

Question 16

What are chemosynthetic autotrophic bacteria?

Answer 16

It oxidises inorganic substances like nitrates, nitrites and ammonia and uses it for the production of ATP.
They recycle nutrients like nitrogen, phosphorus, iron and sulphur.

Question 17

What is heterotrophic bacteria?

Answer 17

They are the most abundant and important decomposers. They help in making curd from milk, production of antibodies, fixing nitrogen in legume roots.
Some are pathogens and cause damage to crops, humans and animals

Question 18

List some diseases caused by bacteria.

Answer 18

Cholera, typhoid, tetanus, citrus canker.

Question 19

How does bacteria reproduce?

Answer 19

By fission.
In unfavorable condition by producing spores.
Sexually by the transfer of primitive DNA from one to another.

Question 20

What is mycoplasma?

Answer 20

Organisms that lack cell walls.
Smallest living cell and can survive without oxygen. Pathogenic to animals and plants.

Question 21

Write about kingdom protista.

Answer 21

It contains all single cell eukaryotes. Primarily aquatic and form links with plants, animals and fungi.

Question 22

What is the structure and reproduction method of protista?

Answer 22

Cell body contains well defined nucleus and other membrane bound organelles. Have flagella or cilia.
Asexual reproduction by cell fusion and sexually by zygote formation.

Question 23

What are the five types of kingdom protista ?

Answer 23

Chrysophytes
Dinoflagellates
Euglenoids
Slime moulds
Protozoans

Question 24

Write about chrysophytes.

Answer 24

It includes diatoms and desmids.
Found in fresh and marine water, floats passively in water.
Photosynthetic
Have two layers of cell wall and an embedded silicon.

Question 25

What is diatomaceous earth?

Answer 25

Accumulation of cell wall deposits of diatoms. It is used for polishing, filtration of oil and syrup.
Diatoms are the chief producers in the ocean .

Question 26

Write the morphology of dinoflagellates.

Answer 26

Marine and photosynthetic.
Yellow, green, blue, red or brown depending on the main pigment in their cells.
Cell walls have cellulose on the outer surface.
Two flagella - one longitudinal and other transverse.
Release toxins

Question 27

Why does the sea appear red?

Answer 27

Red dinoflagellates undergo rapid multiplication that they make the sea appear red. Eg gonyaulax