Biology class 9thClass Matric Part 1 Notes

UNIT 3 Matric Part 1 Class 9TH BIOLOGY

Matric Part 1 Class 9TH BIOLOGY Unit 3 Biodiversity Short And Simple Questions And Answers

These 9th-class biology notes are prepared according to the syllabus of all Punjab Boards. Other boards other than Punjab do not follow class 9 biology notes. These Punjab boards are Gujranwala Board, Lahore Board, Faisalabad Board, Multan Board, Rawalpindi Board, Bahawalpur Board Sargodha Board, DG Khan Board, Sahiwal Board.

Questions And Answers

Q1: How many kinds of organisms are present on the earth?

Ans: The earth is inhabited by at least 10 million kinds of organisms, but less than one-third of these have been studied and cataloged (put in record) by biologists.

Q2: Name the principal groups of organisms?

Ans: Following are the principal groups of organisms:

1. Prokaryotes
2. Protists
3. Fungi
4. Plants
5. Animals

Q3: Define biodiversity?

Ans: Definition:
“The measure of the variety of organisms present in different ecosystems is called biodiversity. It refers to variety within species and among species.
Meaning:
The term ‘Biodiversity has been derived from two terms,
‘bio’ Life
‘diversity” Variety

Q4: What do you mean by flora and fauna?

Ans: Flora:
“The diversity of plants in a particular region is called Flora.”
Fauna:
“The diversity of animals in a particular region is called Fauna.”

Q5: On what factors the flora and fauna of a region depend?

Ans: The flora and fauna in a region depend on:
1. Climate
2. Altitude
3. Soils
4. Presence of other species

Q6: How biodiversity is distributed on earth?

Ans: Biodiversity is not distributed evenly on Earth,
Tropics:
It is richest in the tropics.
Temperate Regions:
Temperate regions also have many species.
Polar Regions:
Polar regions have fewer species.

Q7: How biodiversity has evolved?

Ans: Biodiversity found on earth today is the result of 4 Billion years of evolution.

Q8: What do you know about the origin of life on earth?

Ans: The origin of life is not well known to science, though limited evidence suggests that until 600 million years ago, all life consisted of bacteria and similar unicellular organisms.

Q9: Describe the importance of biodiversity?

Ans: The biodiversity is important in many ways.
(1) Food:
Biodiversity provides food for humans.
(ii) Drugs:
A significant proportion of drugs are derived directly or indirectly from biological sources.
(iii) Industrial materials:
A wide range of industrial materials, e.g. building materials, fibers, dyes, resins, gums, adhesives, rubber, and oil are derived directly from plants.
(iv) Maintenance of Ecosystems:
Biodiversity plays an important role in making and maintaining ecosystems,
(v) Environmental Benefits:
It helps in regulating the chemistry of our atmosphere and water supply.
(vi) Recycling:
Biodiversity is directly involved in recycling of nutrients and providing fertile soils.

Q10: How many types of animals and plants are known to biologists?

Ans: Over 1.5 million types of animals and over 0.5 million types of plants are known to biologists.

Q11: Why does it become difficult to learn about the characteristics of each species?

Ans:1 Living organisms range in complexity from small and simple bacteria to large and complex human beings.
2. Some of them live in sea, others on land. Some walk, others fly. And still others are stationary.
3. Each has its own way of life, i.e. getting food, avoiding unfavorable environmental conditions, finding a place to live, and reproducing its kind.

Q12: How would you differentiate between systematics and taxonomy?

Ans: The branch of biology which deals with classification of organisms is called Taxonomy whereas the branch of biology which deals with classification and also traces the evolutionary history of organisms is called Systematics.

Q13: What are the aims of classification?

Ans: Following are the aims of classification:

Q14: What do you mean by Taxa and Taxonomic hierarchy?

Ans: To determine similarities and differences among organisms so that they can be studied easily.

Q15: To find the evolutionary relationships among organisms?

Ans: “The groups into which organisms are classified are called as Taxa.”

Q16: Write the classification of human being?

Ans:1 Taxa
2. Kingdom
3. Phylum
4. Class….
5. Order…
6. Family.
7. Genus..
8. Specie.
9. Human
10. Animalia
11. Chordata
12. Mammalia
13. Primates
14. Hominidae
15. Homo
16. H.Sapiens

Q17: Write the classification of pea plant?

Ans:1 Taxa
2. Pea
3. Kingdom
4. Phylum..
5. Class…
6. Order..
7. Family….
8. Genus….
9. Specie.
10. P.sativum

Q18: Define species?

Ans: “A group of organisms which can interbreed freely among them and produce fertile off springs, but are reproductively isolated from all other groups in nature is called as species.”
Example:
Human Beings

Q19: What is Mule?

Ans: In the definition of species, we must emphasize “in nature” because two organisms related to two different but closely related species can cross-breed under artificial conditions. But in such unnatural crosses they produce an infertile offspring.
A cross between a male donkey and female horse produces an infertile offspring called Mule

Q20: What is contribution of Aristotle in classification of living organisms?

Ans: The earliest known system of classification of organisms comes from the Greek philosopher Aristotle. He classified all living organisms known at that time in two groups:
Plants
Animalia

Q21: Describe contribution of following scientists for classification of living organisms?

Ans: (1) Ibn Rushd (Averroes): In 1172, Ibn Rushd translated Aristotle’s book ‘de Anima” (On the Soul) in Arabic.
(ii) Augustus Rivinus:
He introduced the taxon of “order”.
(iii) Andrea Caesalpino:
He divided plants into fifteen groups and called them “genera”.

Q22: What do you know about classification system By Carolus Linnaeus?

Ans: He grouped species according to similar physical characteristics and he divided nature into three kingdoms:
(1) Mineral
(ii) Vegetable
iii) Animal
He used five ranks in classification:
(1) Class
(ii) Order
(iii) Genus
(iv)Species
(v) Variety
Linnaeus is best known for his introduction of the method still used to formulate the scientific name of every species.

Q23: Why two kingdom classification system was rejected?

Ans: Some taxonomists found this system unworkable because:
Many unicellular organisms like Euglena have both plant like (presence of chlorophyll) and animal-like (heterotrophic mode of nutrition and lack of cell wall) characters. So there should be a separate kingdom for such organisms.
This system also ignores the difference between organisms having prokaryotic and those having eukaryotic cells.

Q24: Who proposed three-kingdom classification and what were the problems with kingdom system?

Ans: Introduction:
In 1866, Earnst Hackel solved the first objection and presented three-kingdom classification
system.
Objections:
This system did not clear the difference between prokaryotes and eukaryotes.
Fungi were still placed in the Kingdom Plantae. Some biologists disagreed about the position of Fungi in kingdom Plantae. Fungi resemble plants in many ways but are not autotrophs. They are special form of heterotrophs and get their food by absorption. They do not have cellulose in their cell walls, rather they possess Chitin.

Q25: What is the role of E-Chatton?

Ans: In 1937, F-Chatton suggested the terms of “Procaryotique to describe bacteria and “Fucariotique to describe animal and plant cells.

Q26: What is the basis of five-kingdom classification system?

Ans: Cellular organization:
The levels of cellular organization, i.e. prokaryotic, unicellular eukaryotic and multi- cellular eukaryotic.
Modes of nutrition:
The principle modes of nutrition, i.c. photosynthesis, absorption and ingestion.
Kingdom Monera:
It includes prokaryotic organisms i.e. they are made of prokaryotic cells. Monerans are unicellular, although some types form chains, clusters, or colonies of cells. Most are heterotrophic but some perform photosynthesis.
Examples:
Bacteria
Cyanobacteria

Q27: Write down two characteristics of kingdom protista?

Ans: Kingdom protista:
1. It includes eukaryotic unicellular and simple multicellular organisms.
2. These organisms may be photosynthetic are heterotrophic.

Q28: Write two characteristics of kingdom fungi.

Ans: Kingdom Fungi:
1. It includes eukaryotic multicellular heterotrophs which are absorptive in their nutritional mode.
2. They live on organic material, secrete digestive enzymes and absorb small organic molecules.

Q29. Describe two characteristics of kingdom Plantae?

Ans: Kingdom Plantae:
It includes eukaryotic multicellular autotrophs.
They have multicellular sex organs and form embryos during their life cycles.
Examples:
Mosses, ferns and flowering plants are included in kingdom Plantae.

Q30: How can you divide five kingdoms into two groups on the basis of types of cells?

Ans: Five kingdoms can divided into two groups on basis of types of cells in following ways:

(1) Kingdom Monera (organisms with prokaryotic cells)
(ii) Kingdom Protista, fungi, Plantae, Animalia (organisms with eukaryotic cells)

Q31: What are prions and viroids?

Ans: Prions and viroids are acellular forms of organisms. Both of these particles cause infectious diseases in certain plants. They are not included in five-kingdom classification.
Prions:
They are composed of proteins only.
Viroids:
They are composed of circular RNA only.

Q32: Clarify that viruses are living or non-living?

Ans: Viruses are at the borderline of living and non living. They have both non living and living features which distinguish their unique identity.
Non-Living Feature:
Due to their crystalline nature they are considered as non living.
They are acellular i. e, they do not have cellular organization.
Living Features:
They contain DNA or RNA normally encased in a protein coat.
They reproduce, but only in living cells.
They cause a number of diseases in living cells.
Conclusion:
They are not considered as organisms and thus are not assigned any place in the five-kingdom classification system.

Q33: Define binomial nomenclature?

Ans: Introduction:
Binomial nomenclature is the method of giving scientific names to living organisms.
Meaning:
“bi-nomial means “two names”
Format:
As the word “binomial” suggests, the scientific name of any living organism consists of two names: the first is the genus name and the second one is the name of the species.
Example
The Scientific name of human beings is llomo sapiens.

Q34: State any two rules for suggesting scientific names to living organisms?

Ans: Some of the rules which are universally adopted while suggesting and documenting scientific
names, are:
Scientific names are usually printed in italics, such as Homo sapiens. When handwritten, they are underlined.
The first term (generic name) always begins with a capital letter.

Q35: What are the problems with common names of living organisms?

Ans: Common names have no scientific basis.
Example:
A fish is a vertebrate animal with fins and gills. But several common names do not fit a biologist’s definition of fish like:
1. Silverfish
2, Crayfish
3. Jellyfish
4. Starfish

Q36: Write down scientific names of following.
Ans: (a) Onion
(b) Starfish
(c) House crow
(d) Orchid tree

Q37: Define Extinct species?

Ans: “In an ecosystem, a species is called extinct when there is no doubt that the last individual of that species has died in that ecosystem.”
Example:
Dinosaurs

Q38: What are endangered species? Give examples?

Ans: A species is called endangered when it is at risk of extinction in near future.
Examples:
Indus dolphin, Marco Polo sheep, Houbara bustard.

Q39: Write a short note on Eucalyptus plants?

Ans: Eucalyptus plants were imported from Australia and introduced in Pakistan. These plants consume more water and have disturbed the water table (level of underground water). It harms other small plants that grow near Eucalyptus trees.

Q40: What is the effect of deforestation on biodiversity?

Ans: Effects of deforestation:
Deforestation affects the amount of water in soil and moisture in atmosphere. When there are no trees to keep soil in place, there are more chances of soil erosion. Essential nutrients are washed out of soil. Rivers become choked up with mud and silt, which can cause floods. Deforestation also reduces the sources of rains.

Q41: What is the role of over-hunting in extinction?

Ans: Over-hunting has been a significant cause of the extinction of hundreds of species and the endangerment of many more such as whales, ibex, urial, markhor (the national animal of Pakistan) etc. Commercial hunting, both legal and illegal, is the principal threat.

Q42: What are the main causes of loss of biodiversity in Pakistan?

Ans: Pakistan today faces severe threats to its animal and plant species. The main causes of this loss are:
Loss of natural habitats
Rapid growth in human population
Prevailing poverty in rural areas
Low literacy rate

Q43: Which organizations are working for the conservation of biodiversity?

Ans: The following organizations are working for the conservation of biodiversity in Pakistan.
The International Union for the Conservation of Nature and Natural Resources (IUCN)
World Wildlife Fund Pakistan
Pakistan’s Ministry of Environment
Other government and non-government institutions

Q44: Which organization has prepared first red list of Pakistan?

Ans: The IUCN has prepared the first national Red List (list of endangered or threatened species).

Q45: Write names of animals to which Northern Areas provide habitat?

Ans: The Northern Areas of Pakistan provide habitats:
1. Musk deer
2. Snow leopard
3. Astore markhor
4. Ilimalavan ibex
5. Woolly Flying squirrel
6. Brown bear

Q46: How many migratory birds are killed each year?

Ans: It is estimated that about 200.000 of the one million migratory birds passing through Chitral are killed during migration.

Q47: What herders do with bear cubs?

Ans: The herders capture the bear cubs and sell them to the trainers who train them and sell them to the foreigners.

Q48: Write a short note on Houbara Bustard?

Ans: This bird flies to Pakistan in winter season from former Soviet territory and settles in Cholistan and Thar deserts. The decline in its population is due to hunting by foreigners and destruction of its habitats.

Q49: Name the national animal and bird of Pakistan?

Ans: National Animal:
Markhor is the national animal of Pakistan.
National Bird:
Chakor partridge is the national bird of Pakistan.

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