Your cart is empty.
Practice each question, then open the answer or worked solution.
What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?
Cyanobacteria are capable of fixing nitrogen with the help of specialised cells called the heterocyst. They enrich soil fertility. Hence BGA’s are used in agricultural fields. E.g. Colonies of Nostoc and Anabaena grow in Paddy fields.
Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you place the slide under the microscope and observe the following features:-
a. Unicellular
b. Well-defined nucleus
c. Biflagellate–one flagellum lying longitudinally and the other transversely.
What would you identify it as? Can you name the kingdom it belongs to?
According to the listed features, the organism must be a dinoflagellate. All the eukaryotic unicellular organism belonging to the kingdom Protista.
How is the five-kingdom classification advantageous over the two kingdom classification?
Two kingdom classifications did not distinguish between the prokaryotes and eukaryotes
They did not distinguish between unicellular and multicellular organisms
They also did not distinguish between autotrophic/photosynthetic and heterotrophic/non-photosynthetic organisms.
Polluted water bodies have usually a very high abundance of plants like Nostoc and Oscillitoria. Give reasons.
Polluted water bodies are rich in nutrients, especially in nitrogen content which provides favourable conditions to algae like Nostoc and Oscillotoria to bloom in the water bodies.
Are chemosynthetic bacteria-autotrophic or heterotrophic?
Chemosynthetic bacteria are autotrophic. They gain energy for the synthesis of food by oxidising inorganic substances.
The common name of the pea is simpler than its botanical (scientific) name Pisum sativum. Why then is the simpler common name not used instead of the complex scientific/ botanical name in biology?
Pea is known by different names in different countries. So instead of calling a variety of names, scientific names are provided, which are same in the world throughout. It is worldwide standardization of name.
A virus is considered as a living organism and an obligate parasite when inside a host cell. But the virus is not classified along with bacteria or fungi. What are the characteristics of the virus that are similar to non-living objects?
1. Viruses have no complete cellular structure.
2. Don’t show growth, division, metabolism and lack respiration.
3. High specific gravity
4. Don’t follow Robert Koch’s postulate
5. Cannot be grown under “in vitro” condition.
In the five-kingdom system of Whittaker, how many kingdoms are eukaryotes?
Eukaryotes are organisms whose nucleus and cell is bounded by a membrane. Four kingdoms have eukaryotic organisms- a) Protista b) Fungi c) Plantae d)Animalia.