Chapter 18

Question 1

Ecology:

Answer 1

• The branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms.

Question 2

Bio-diversity:

Answer 2

• Degree of variation of life forms in an ecosystem.
• The total number of different species living in a defined area, their abundance and genetic variation in ecosystem or biome. It is also possible to consider the biodiversity of earth.
• Specie Diversity and Genetic Diversity

Question 3

Ecosystem:

Answer 3

• A self contained system. A community of organisms and their surroundings, the environment in which they live and with which they live.

Question 4

Habitat:

Answer 4

• A locality in which an organism lives.
• Or the particular location and type of local environment occupied by a population or organism, characterized by its physical features or by its dominant producers (such as sugar cane fields, rocky shore)

Question 5

Niche:

Answer 5

• Role of organisms in ecosystem, how an organism’s fits into the system
• Describes that how organism interacts, how it obtain energy, how it interacts with other organisms etc.
  Kangaroos in Australia, Zebra in savannah.

Question 6

• Population:

Answer 6

All of the organisms of one particular species within a specified area at particular time, sharing the same gene pool and more or less isolated from other populations of the same species

Question 7

Community:

Answer 7

All of the populations of all the different species within a specified area at particular time.

Question 8

Classification

Answer 8

• The science of classification ( arranging in groups) is called Taxonomy.
• Taxa (taxon) = A general name for the groups or categories within classification system.

Question 9

The scheme of classification

Answer 9

Similar Species are grouped together in Genus, so similar genera are grouped into Families. Then families to Orders by following same approach and same can be extended towards making Classes, Phyla and Kingdom.

Question 10

The five kingdoms:

Answer 10

• Prokaryotae
• Protoctista
• Fungi
• Plantae
• Animalia

Question 11

Characteristic Features Of Kingdom

Protoctista:

Answer 11

• Single celled organism predominant but if multicellular, not differentiated into tissues.
• Cells are eukaryotic, some may have cell walls also linear Nuclear chromosome of DNA. with histone proteins attached.
• Large ribosomes ( 80s) are present.
• Nutrition is heterotrophic or autotrophic.
• –Amoeba, Chlamydomonas, paramecium etc.

Question 12

Characteristic Features Of Kingdom Fungi:

Answer 12

• No motile, not differentiated into tissues though multicellular ( except unicellular yeast).
• Cells are eukaryotic.
• Linear Nuclear chromosome of DNA with histone proteins attached.
• Cell walls of chitin.
• Main nutrition is heterotrophic.
• Via Spore reproduction.

Question 13

Characteristic Features Of Kingdom Plantae:

Answer 13

• Multicellular organisms, differentiated into tissues, are non motile organisms( but gametes of mosses and ferns are motile).
• Cells are eukaryotic, with distinct nucleus and histone attached proteins
• Large ribosomes(80s) present)
• Autotrophic nutrition
• Cell wall is largely of cellulose

Question 14

Characteristic Features Of Kingdom Animalia:

Answer 14

• Multicellular organisms, differentiated into tissues, are motile organisms
• Cells are eukaryotic, with distinct nucleus and histone attached proteins
• Large ribosomes(80s) present)
• Heterotrophic nutrition
• Cell wall is absent