Federal Board 9th Biology Notes Chapter 2 / Biodiversity Complete Notes

FBISE 9^th Class Biology  New Book Notes Chapter 2, Fereral Board 9th biology notes chapter 2, fbise Class 9th biology Notes

SHORT  QUESTIONS

Q1. Why are the following scientists famous for?

(a) Aristotle                                        (b) Carolus Linnaeus                (c) Carl Woese

Ans: Aristotle:

The two kingdom system was first proposed by Aristotle. The earliest known system of classification of organisms comes from the Greek philosopher Aristotle, who classified all living organisms known at that time as either in the group ‘plants’ or in ‘animals’

Carolus Linnaeus:

Carolus Linnaeus introduce Binomial Nomenclature.  He grouped species according to similar physical characteristics.

Carl Woese:

Carl Woese introduced a three domains system of classification. The three domains of life are Archaea, Bacteria and Eukarya

Q2. Define:         

(a) Biodiversity                       (b) Classification                     (c) Taxonomy                                     (d) Systematics                 (e) Domain                                (f) Taxa                      (g) Species.

Ans:

Biodiversity

Biodiversity is the variety of the living organisms present in an ecosystem Biodiversity is the richness and variety of living organisms on Earth

Classification:

Biologists have devised ways of grouping organisms The grouping of organisms on the basis of similarities and dissimilarities is called classification

Taxonomy:

Taxonomy is the branch of biology concerned with identification, naming and classification of organisms.

Systematics:

The scientific study of diversity of organisms and their evolutionary relationship is called systematic

Domain:

In biology, a domain means the largest of all groups in the classification of life. Domain is group of kingdoms or taxonomic category above the kingdom

Taxa:

The group into which organisms are classified are known as taxonomic categories or taxa (singular ‘taxon’). The taxa form a ladder, called taxonomic hierarchy.

Species:

Ans: A species is defined as a group of organisms capable of interbreeding and producing fertile offspring.

Q3. What is domain? Name the three domains of life.

OR

List the three distinct domains into which living organisms are broadly classified.

Ans: In biology, a domain means the largest of all groups in the classification of life. Domain is group of kingdoms or taxonomic category above the kingdom

Types of domain:

• The Domain Archaea
• The Domain Eukarya
• The Domain Bacteria

Q4. What are basis of classification of life into domains?

Ans: Classification into three domains is based on.

• Difference in the sequence of nucleotides in the rRNA (ribosomal Ribonucleic acid) of the cell.
• The cell’s membrane lipid structure.
• Sensitivity to antibiotics.

Q5. Can you differentiate between?

Ans:

Differentiate between Bacteria and Protists:

Differentiate between Fungi and Plants:

 Differentiate between Plants and animals;

Q6. Answer the following with supportive reasons.

(a) Which the simplest domain?

(b) Which is the complex domain?

(c) Are most bacteria harmful?

(d) Which domain/s can flourish or survive in most adverse conditions?

Ans

Which the simplest domain?

Ans: The Archaea domain is considered simpler than the other two domains, Bacteria and Eukarya, for several reasons.

Cellular Complexity:

Archaea are prokaryotic organisms, meaning they lack a true nucleus and membrane-bound organelles, making their cellular structure simpler compared to eukaryotic organisms found in the Eukarya domain

Which is the complex domain?

Ans: Eukarya encompasses a wide range of organisms that are characterized by having complex, eukaryotic cells with membrane-bound organelles, including a nucleus containing DNA

Are most bacteria harmful?

Ans: No most bacteria are not harmful some are beneficial also Here are some ways in which bacteria can be beneficial

• Nutrient Cycling
• Nutrient Cycling
• Bioremediation
• Symbiotic Relationships

Which domain/s can flourish or survive in most adverse conditions?

Ans: The domain that can flourish or survive in the most adverse conditions is Archaea.     Archaea are known for their ability to thrive in extreme environments that would be inhospitable to most other organisms. Some of the extreme environments where Archaea can be found include:

 Extreme Temperatures:

Archaea can survive in environments with extremely high temperatures.

Extreme pH:

Archaea are also found in environments with extremely acidic or alkaline pH levels, such as acidic hot springs or alkaline soda lakes.

High Salinity:

Archaea are capable of surviving in environments with high salt concentrations, such as salt flats, salt lakes.

Extreme Pressure:

Certain Archaea are found in deep-sea environments, including the ocean floor and hydrothermal vents, where they are exposed to extremely high pressures

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Q7.Compare the two-kingdom, three kingdom and five-kingdom system of classification.

Ans:

Two-kingdom classification system

It is the oldest system and classifies organisms into two kingdoms, the Plantae and Animalia.

The kingdom Plantae includes the autotrophs. Bacteria, fungi and algae were also included in the kingdom.

The organisms which depend on autotrophs or other heterotrophs are included in the kingdom Animalia.

Many unicellular organisms like Euglena have both plant like (presence of chlorophyll) and animal like (heterotrophic mode of nutrition in darkness and lack of cell wall) characteristics. So separate kingdom was introduced for such organisms.

Three-kingdom classification system

This system include. The kingdom Plantae includes the autotrophs Bacteria, fungi and algae were also included in the kingdom.

The organisms which depend on autotrophs or other heterotrophs are included in the kingdom Animalia.

The German Scientist Ernst Haeckel proposed of a third kingdom, Protista to accommodate Eugleno  to like organisms and to separate unicellular microscopic organisms from multicellular ones.

Five-kingdom classification system

All prokaryotic organisms are included in kingdorn Monera. They are unicellular, small and are relatively simple in structure. This kingdom includes bacteria and cyanobacteria.

Protists include eukaryotic organisms with unicellular or colonial organization. These are mostly aquatic. It is a diverse group of organisms. It includes Animal like protist called protozoa e.g Amoeba. Plant like protists called algae e.g.. Euglena Fungi like protists e.g., slime molds.

Fungi are eukaryotic organisms which have chitin in their cell wall. Fungi are saprotrophic decomposers. Mostly fungi are multicellular. Some fungi are unicellular. The examples of fungi are black bread mold, yeast, mushroom, etc.

The members of kingdom plantae are eukaryotic multicellular and autotrophic with chloroplasts containing chlorophyII. Their cell wall is made up of cellulose eg moss mustard

Animals are multicellular heterotrophic eukaryotes Animals lack cell wall and chlorophyII. They can generally move from place to place This kingdom includes invertebrates eg. Insects, star fish and vertebrates e g fish, frogs and man

Q8. Compare the three-domain system of classification.

Ans: Comparison of three domain system of classification:

The Domain Archaea:

• The domain Archaea have the following characteristics.
• Archaea are prokaryotic cells.
• The cell walls of Archaea contain no peptidoglycan.
• The rRNA (ribosomal RNA) are not found in Bacteria and Eukarya.
• Archaea are not sensitive to some antibiotics that affect bacteria sensitive to some antibiotics that affect the Eukarya.
• Archaea often live in extreme environment.
• Archaea membrane can withstand higher temperature and stronger acid concentration.

The domain bacteria:

The domain bacteria have the following characteristics.

• Bacteria are  prokaryotic cells.
• The cell walls of  bacteria contain peptidoglycan.
• They contain rRNA that is unique to bacteria
• Bacteria are sensitive to traditional antibacterial antibiotics but are resistant to most antibiotics that affect Eukarya.

The Domain Eukarya

The domain Eukarya have the following are characteristics:

Eukarya have eukaryotic cells

Not all Eukarya have cells with a cell wall.Their cell wall contains no peptidoglycan

Eukarya contains rRNA that is unique to Eukarya.

Eukarya are resistant to traditional antibacterial antibiotics but are sensitive to most antibiotics that affect eukaryotic cells.

FBISE 9^th Class Biology  New Book Notes Chapter 2, Fereral Board 9th biology notes chapter 2, fbise Class 9th biology Notes

Q9. Why mule is not regarded as a species.

Ans:

Species is a group of similar organisms individuals capable of interbreeding or exchanging genes among themselves and producing fertile offspring.Cross between a male donkey and a female horse produces mule. It is infertile, because of the odd number of chromosomes, they can’t reproduce. So, it is not a species. Species is the most basic unit of classification, as well as a taxonomic rank

Q10. Complete the following chart:

SLOs Based Short Question

Q1. What are the main aims and objectives of classification?

Ans:

• To determine similarities and differences between organisms.
• To arrange organisms on the basis of similarities and differences.
• Identify the organisms to study them systematically.
• To find out evolutionary relationships among organisms.

FBISE 9^th Class Biology  New Book Notes Chapter 2, Fereral Board 9th biology notes chapter 2, fbise Class 9th biology Notes

Q2. Why are the following scientists famous for? (b) John Ray

(a) Andrea Caesalpino                                   (b) John Ray                           (c) Tournefort

Ans:

Andrea Caesalpino (1519-1603);

He divided plants into fifteen groups and called them genera

John Ray (1627-1705):

He published important works on the classification of plants

Tournefort (1656-1708);

He introduced the taxa of class and species

Q3. Write classification of human and Pea?

Ans: Simple classification of human and pea

Q4. Why is it important for a biologist to understand biological classification?

Ans: Biological Classification:

The arrangement of organisms into groups and subgroups on the basis of their similarities and differences is called biological classification

Importance of Biological Classification to Biologist:

• To understand the great variety of organisms
• To know similarities and differences between organisms.
• To know the generic relationship between organisms
• To know the number of specie and name of organisms

Q5. State the complications of classifying viruses?

Ans:

Viruses show characteristics of both living and non-living things.

The living characteristics of viruses are:

• They occur in different varieties
• They have their own genetic material in the form of either RNA or DNA.
• They reproduce using the material of the host cell they infect.
• They enter the cells of living organisms and cause diseases.

The non-living characteristics of viruses are:

• They lack cellular structure and enzyme system,
• They can be crystallized and store in bottle.
• They do not respire.
• Viruses behave as non-living, inert infectious particles outside the host Viruses are at the borderline of living and non-living. So, they are not included in any domain and kingdom under modern classification.

FBISE 9^th Class Biology  New Book Notes Chapter 2, Fereral Board 9th biology notes chapter 2, fbise Class 9th biology Notes