Question:

Find out what do the terms algal bloom and red-tides signify.

Answer:

Step 1: Research the definitions of algal bloom and red-tides. Step 2: Understand the meaning of the terms by reading about them in a reliable source. Step 3: Summarize the definitions of algal bloom and red-tides.

Question:

What do the terms phycobiont and mycobiont signify?

Answer:

1. Phycobiont and mycobiont are terms used to describe two components of a lichen.

2. A lichen is a composite organism, consisting of a symbiotic relationship between a fungus (mycobiont) and an alga (phycobiont).

3. The mycobiont provides structure and protection for the phycobiont and the phycobiont provides food for the mycobiont through photosynthesis.

4. Therefore, the term phycobiont signifies the alga component of a lichen and the term mycobiont signifies the fungus component of a lichen.

Question:

Give a brief account of viruses with respect to their structure and nature of genetic material. Also name four common viral diseases?

Answer:

1. Viruses are small infectious agents that can only reproduce inside the cells of other living organisms. They are composed of genetic material, either DNA or RNA, surrounded by a protective protein coat.

2. Viruses are much smaller than bacteria, and they are not cells, so they cannot reproduce independently. Instead, they rely on the host cells to replicate their genetic material and produce new viruses.

3. Viruses can cause a variety of diseases in humans, animals, and plants. Common viral diseases in humans include the common cold, influenza, chickenpox, measles, mumps, and rubella.

4. Other common viral diseases include HIV/AIDS, hepatitis, herpes, and warts.

Question:

How are viroids different from viruses?

Answer:

1. Viroids are much simpler than viruses and lack a protein coat.

2. Viroids are composed of only a single molecule of circular, naked, non-coding RNA.

3. Unlike viruses, viroids do not contain any DNA and are not able to encode proteins.

4. Viroids are able to replicate themselves within the cells of the host organism, but they are not capable of independent reproduction.

5. Viroids are able to cause disease in plants, but they are not known to cause disease in animals or humans.

Question:

Describe briefly the four major groups of Protozoa?

Answer:

1. Ciliates: These protozoans are characterized by having cilia, which are short, hairlike structures used for movement and feeding. Examples include Paramecium and Stentor.

2. Flagellates: These protozoans have a single flagellum, or whip-like structure, for movement. Examples include Euglena and Trypanosoma.

3. Amoebas: These protozoans are characterized by their ability to change shape and move by extending and retracting pseudopods, or false feet. Examples include Amoeba and Chaos.

4. Sporozoans: These protozoans are characterized by their ability to form cysts, or dormant stages. Examples include Plasmodium and Toxoplasma.

Question:

Discuss how classification systems have undergone several changes over a period of time?

Answer:

Step 1: Research the history of classification systems and their changes over time.

Step 2: Outline the main points of the changes that have occurred in classification systems.

Step 3: Provide examples of how certain classification systems have evolved over time.

Step 4: Analyze the impact of these changes on the classification systems and how they have affected their use.

Step 5: Draw conclusions about the effectiveness of different classification systems and how they have changed over time.

Question:

What is the nature of cell walls in diatoms?

Answer:

Step 1: Understand what diatoms are.

Diatoms are single-celled algae that are found in oceans, rivers, and other aquatic environments. They are encased in a silica shell, known as a frustule, which is made up of two interlocking halves.

Step 2: Research the nature of cell walls in diatoms.

The cell walls of diatoms are composed of silica, which is a type of glass. The cell walls are rigid and relatively impermeable, which helps to protect the diatom from predators and environmental changes. The cell walls of diatoms also contain a variety of proteins and other molecules that are involved in the growth and development of the organism.

Question:

State two economically important uses of : (a) Heterotrophic bacteria (b) Archaebacteria

Answer:

A. Heterotrophic Bacteria:

1. Industrial Fermentation: Heterotrophic bacteria are used to produce a variety of products such as alcohols, organic acids, enzymes, and vitamins.
2. Bioremediation: Heterotrophic bacteria are used to break down pollutants such as oil, pesticides, and other organic compounds found in contaminated sites.

B. Archaebacteria:

1. Methanogenesis: Archaebacteria are used to produce methane, which is an important source of energy.
2. Extreme Environment Survival: Archaebacteria are able to survive in extreme environments such as hot springs, salt lakes, and deep-sea hydrothermal vents.

Question:

Plants are autotrophic. Can you think of some plants that are partially heterotrophic?

Answer:

Step 1: Understand the definition of autotrophic and heterotrophic. Autotrophic organisms are those that can produce their own food, while heterotrophic organisms rely on other organisms for food.

Step 2: Think of examples of plants that have characteristics of both autotrophic and heterotrophic organisms. Examples include orchids, pitcher plants, and Venus flytraps. These plants are able to produce their own food through photosynthesis, but they also supplement their diets by trapping and consuming insects.

Question:

What are the characteristic features of Euglenoids?

Answer:

1. Euglenoids are unicellular, microscopic organisms that belong to the kingdom Protista.

2. They are mostly aquatic and can be found in freshwater, brackish, or marine environments.

3. They are photosynthetic, meaning they are able to produce their own food through photosynthesis.

4. They have a single, long flagellum that helps them move, as well as two contractile vacuoles that help regulate the amount of water inside the cell.

5. They have a pellicle, a flexible protein-based cell membrane, and an eyespot, which helps them detect light.

6. They have a unique form of nutrition, called holozoic nutrition, which involves the ingestion of food particles.

7. Euglenoids have a unique cell structure, containing a nucleus, mitochondria, and chloroplasts.