Class 9 BiologyChapter 12Revise
Revise diversity and classification
29 flashcards that come back when due, 18 practice questions in exam styles, and one page to print.
Flashcards
Flip a card, then say how well you knew it. Again brings it back in this session, Good and Easy push it further away each time you get it. Your progress is saved in this browser only; there is no account.
What is biodiversity?
The whole variety of living organisms on the Earth, from microbes to the largest trees and animals.
Endemic species?
A species found naturally in only one region of the world. Example: Nilgiri tahr, only in India.
Two conditions for a biodiversity hotspot?
Many endemic species, and heavy loss of natural habitat.
The four global hotspots that include parts of India?
Western Ghats, Himalayas, Indo-Burma (with North East India), Sundaland (with the Nicobar Islands).
How did today's biodiversity arise?
Individuals differ slightly; the differences that helped some survive and breed were passed on and piled up, generation after generation, until new forms appeared.
Seven criteria used to classify organisms?
External features, mode of nutrition, internal structures, cell structure, ecological role, reproduction, genetic similarity (DNA).
Biological classification?
The scientific system of grouping organisms by their similarities and differences.
Pakke Tiger Reserve: which hornbills, and why do old trees matter?
Rufous-necked, Oriental Pied, Great and Wreathed. They nest only in cavities of large old trees.
How did Aristotle group animals?
By habitat (land, water, air) and appearance. An artificial system, about the 4th century BCE.
Two, three, four, five kingdoms: who and when?
Linnaeus 1758, Haeckel 1866 (Protista), Copeland 1938 (Monera), Whittaker 1969 (Fungi).
Why were fungi taken out of the plant kingdom?
They make no food; they are heterotrophs that absorb nutrients, many from dead matter.
The four bases of the five kingdom system?
Cell type, cell structure (wall or not), level of organisation, mode of nutrition.
Kingdom Monera in one line?
Unicellular prokaryotes: bacteria, archaea, cyanobacteria. No true nucleus.
Kingdom Protista in one line?
Unicellular eukaryotes, no wall or a cellulose wall: Amoeba, Paramecium, Euglena, Chlamydomonas.
Kingdom Fungi in one line?
Mostly multicellular eukaryotes with chitin walls that absorb food; most are saprophytes (decomposers).
Yeast is one cell. Why is it a fungus?
Its cell wall is made of chitin, the fungal wall material.
Five classes of Kingdom Plantae?
Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, Angiosperms.
Bryophytes: why the amphibian nickname?
They live on damp land but need water to reproduce.
What do pteridophytes have that bryophytes lack?
True roots, stems and leaves, and vascular tissue (xylem and phloem). Still no seeds.
Gymnosperm seed versus angiosperm seed?
Gymnosperm: naked, often on cones. Angiosperm: enclosed in a fruit.
What is a lichen, and why is it a bioindicator?
An alga and a fungus living together. Its colour changes with air pollutants.
What splits animals into chordates and non-chordates?
The notochord, a flexible rod-shaped structure. Chordates have it at some stage.
The eight invertebrate phyla in order?
Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata.
Where do tissues, bilateral symmetry and two openings first appear?
Tissues: Cnidaria. Bilateral symmetry: Platyhelminthes. Two openings: Nematoda.
The levels of classification, top to bottom?
Kingdom, Phylum, Class, Order, Family, Genus, Species.
Rules for writing a scientific name?
Two parts, genus then species; genus capitalised, species lower case; italics in print, underlined by hand.
Three domains, and who proposed them?
Bacteria, Archaea, Eukarya. Carl Woese, 1977, from DNA data.
What are fossils, and what do they show?
Traces of past life kept in layered rock, sand or mud. The deeper and older the layer, the simpler the life in it, as a rule.
Four human causes of biodiversity loss?
Pollution, deforestation, overuse of resources, climate change.
Practice questions
Questions in the styles CBSE uses: multiple choice, assertion and reason, case based and labelling a diagram. Each answer comes with the reason. Send any question to a friend; the link opens it here and carries nothing about you.
A friend sent you this question. Give it a go.
-
1Multiple choice India's hotspots
Which pair of regions are both global biodiversity hotspots that include parts of India?
The four hotspots are the Western Ghats, Himalayas, Indo-Burma and Sundaland. A large area alone does not make a hotspot.
Show the answer
B. The four hotspots are the Western Ghats, Himalayas, Indo-Burma and Sundaland. A large area alone does not make a hotspot.
-
2Multiple choice How to classify
A student sorts a pond's organisms into producers, consumers and decomposers. Which criterion is she using?
Producer, consumer and decomposer describe the role an organism plays in its ecosystem.
Show the answer
B. Producer, consumer and decomposer describe the role an organism plays in its ecosystem.
-
3Multiple choice Systems over time
Which order of classification systems runs from earliest to latest?
Linnaeus 1758 (two), Haeckel 1866 (three), Copeland 1938 (four), Whittaker 1969 (five).
Show the answer
B. Linnaeus 1758 (two), Haeckel 1866 (three), Copeland 1938 (four), Whittaker 1969 (five).
-
4Multiple choice Five kingdoms
Cells from a spoonful of curd are single, have a rigid wall and no membrane-bound nucleus. Their kingdom is:
Single cells with no true nucleus are prokaryotes, the kingdom Monera. These are bacteria such as Lactobacillus.
Show the answer
C. Single cells with no true nucleus are prokaryotes, the kingdom Monera. These are bacteria such as Lactobacillus.
-
5Multiple choice Five kingdoms
A log in a damp forest is covered in white threads and small umbrella-shaped bodies. The organism is most likely:
White threads (mycelium) feeding on dead wood and spore-bearing mushrooms are signs of a fungus, a decomposer.
Show the answer
B. White threads (mycelium) feeding on dead wood and spore-bearing mushrooms are signs of a fungus, a decomposer.
-
6Multiple choice Plant kingdom
A plant has true roots, stems and leaves and xylem and phloem, but makes no seeds. It belongs to:
Vascular tissue without seeds marks the pteridophytes, such as ferns.
Show the answer
B. Vascular tissue without seeds marks the pteridophytes, such as ferns.
-
7Multiple choice Animal kingdom
A sea animal has spiny skin and a hard internal skeleton of calcium carbonate, but no notochord. Its phylum is:
Echinoderms such as starfish have an internal calcium carbonate skeleton yet are invertebrates.
Show the answer
C. Echinoderms such as starfish have an internal calcium carbonate skeleton yet are invertebrates.
-
8Multiple choice Hierarchy and names
The tiger and the lion share every level down to, and including:
Both are Panthera: same genus, different species (tigris, leo).
Show the answer
B. Both are Panthera: same genus, different species (tigris, leo).
-
9Multiple choice Hierarchy and names
Which handwritten form of the mango's scientific name follows the rules?
Genus first with a capital, species in lower case, and underlined because it is handwritten.
Show the answer
B. Genus first with a capital, species in lower case, and underlined because it is handwritten.
-
10Assertion and reason Plant kingdom
Assertion (A) A moss is often compared to a frog.
Reason (R) Bryophytes live on land but need water for reproduction.
Both true, and the reason explains the name: like amphibians, they live on land yet depend on water to reproduce.
Show the answer
A. Both true, and the reason explains the name: like amphibians, they live on land yet depend on water to reproduce.
-
11Assertion and reason Five kingdoms
Assertion (A) Yeast is placed in Kingdom Fungi.
Reason (R) Yeast is a multicellular organism.
Yeast is a fungus, but it is unicellular. It is a fungus because its cell wall is made of chitin.
Show the answer
C. Yeast is a fungus, but it is unicellular. It is a fungus because its cell wall is made of chitin.
-
12Assertion and reason Animal kingdom
Assertion (A) Many arthropods can survive in dry, exposed places.
Reason (R) Their hard external skeleton reduces water loss and protects the body.
Both true, and the exoskeleton is exactly why they cope with dry places.
Show the answer
A. Both true, and the exoskeleton is exactly why they cope with dry places.
-
13Assertion and reason Five kingdoms
Assertion (A) Cyanobacteria are placed in Kingdom Monera.
Reason (R) Cyanobacteria carry out photosynthesis.
Both true, but they are in Monera because they are unicellular prokaryotes, not because they photosynthesise.
Show the answer
B. Both true, but they are in Monera because they are unicellular prokaryotes, not because they photosynthesise.
-
14Case based Plant kingdom
A nature walk after the monsoon
Class 9 students walked through a damp forest. They noted a green velvety mat on a stone wall, tall feathery plants under the trees that had no flowers, white umbrella-shaped growths on a rotting log, and a tall tree with red flowers and long pods.
(i) The green velvety mat on the wall is most likely:
Mosses (bryophytes) grow as green mats on damp walls and stones.
Show the answer
B. Mosses (bryophytes) grow as green mats on damp walls and stones.
(ii) The feathery plants with no flowers, if they have xylem and phloem but no seeds, are:
Vascular tissue with no seeds: pteridophytes, such as ferns.
Show the answer
A. Vascular tissue with no seeds: pteridophytes, such as ferns.
(iii) The tree with red flowers and pods is an angiosperm because it:
Flowers and seeds enclosed in fruits (here, pods) mark the angiosperms.
Show the answer
B. Flowers and seeds enclosed in fruits (here, pods) mark the angiosperms.
-
15Case based Systems over time
Riya's five organisms
Riya listed five organisms: Amoeba, a bacterium, a mushroom, a mango tree and a cow. She tried to place them using each classification system in turn, from two kingdoms to five.
(i) Under the two kingdom system, where would the mushroom go?
It does not move, so it was filed with plants, even though it makes no food.
Show the answer
B. It does not move, so it was filed with plants, even though it makes no food.
(ii) Copeland's 1938 system gave one of her organisms a brand new kingdom, Monera. Which?
Copeland separated bacteria, which lack a true nucleus, into Monera.
Show the answer
B. Copeland separated bacteria, which lack a true nucleus, into Monera.
(iii) In the five kingdom system, how many different kingdoms do Riya's organisms fill?
Amoeba: Protista. Bacterium: Monera. Mushroom: Fungi. Mango: Plantae. Cow: Animalia. All five.
Show the answer
D. Amoeba: Protista. Bacterium: Monera. Mushroom: Fungi. Mango: Plantae. Cow: Animalia. All five.
-
16Case based Fossils and threats
The logging road
A new road was cut through a forest and the largest, oldest trees along it were logged. Two years later, birdwatchers counted far fewer hornbills, and fewer young fruit trees were coming up in the area.
(i) Why did the hornbill numbers fall?
Logging the big old trees took away both the cavities hornbills breed in and the fruit they live on.
Show the answer
B. Logging the big old trees took away both the cavities hornbills breed in and the fruit they live on.
(ii) Why were fewer young fruit trees growing?
Hornbills disperse the seeds of the fruits they eat. Fewer birds, fewer seeds carried.
Show the answer
A. Hornbills disperse the seeds of the fruits they eat. Fewer birds, fewer seeds carried.
(iii) Which step would most help the forest recover?
Protecting habitat, especially old trees, lets the connected species recover.
Show the answer
B. Protecting habitat, especially old trees, lets the connected species recover.
-
17Label the diagram Plant kingdom
This is a sunflower stem in cross section, with one vascular bundle enlarged. Label the numbered parts.
The outer layer is the epidermis. In each bundle, phloem lies towards the outside, xylem towards the centre, and the lateral meristem between them. Rhizoids belong to mosses and mycelium to fungi.
Show the answer
1: Epidermis, 2: Phloem, 3: Lateral meristem, 4: Xylem. The outer layer is the epidermis. In each bundle, phloem lies towards the outside, xylem towards the centre, and the lateral meristem between them. Rhizoids belong to mosses and mycelium to fungi.
-
18Label the diagram Animal kingdom
Name the phylum of each numbered animal.
1 a sponge (pores), 2 a jellyfish (tentacles), 3 an earthworm (segments), 4 a crab (jointed legs, exoskeleton), 5 a starfish (spiny skin).
Show the answer
1: Porifera, 2: Cnidaria, 3: Annelida, 4: Arthropoda, 5: Echinodermata. 1 a sponge (pores), 2 a jellyfish (tentacles), 3 an earthworm (segments), 4 a crab (jointed legs, exoskeleton), 5 a starfish (spiny skin).
Memory aids
Memory aid
Hotspot = rare + at risk
Many endemics AND much habitat lost
Both boxes must be ticked. A rich area that is still intact is not a hotspot.
Memory aid
Every Naturalist Inspects Cells, Ecology, Reproduction, Genes
External, Nutrition, Internal, Cell, Ecological role, Reproduction, Genetic
The seven criteria from a glance to the DNA.
Memory aid
Plants And Protists Make Fungi
Plantae and Animalia 1758, Protista 1866, Monera 1938, Fungi 1969
The kingdoms in the order they were added.
Memory aid
Four questions to a kingdom
Nucleus? Cells? Wall? Wall of what?
No true nucleus: Monera. One cell: Protista. No wall: Animalia. Chitin: Fungi. Cellulose: Plantae. (Yeast is the exception: one cell, chitin, Fungi.)
Memory aid
Water to land
Algae, Bryophytes, Pteridophytes, Gymnosperms, Angiosperms
Each step adds one thing: a body on land, plumbing, naked seeds, flowers and fruits.
Memory aid
Poor Cnidarians Plan Nice And Artful Meals Elegantly
Porifera to Echinodermata
The eight invertebrate phyla in book order.
Memory aid
King Philip Came Over For Good Soup
Kingdom, Phylum, Class, Order, Family, Genus, Species
Down the hierarchy: fewer members, more shared features.
Memory aid
Capital city, small village
Genus species
The genus is the big capital; the species is small letters. Italics in print, underline by hand.
One page summary
One page summary
Class 9 Biology, Chapter 12: Patterns in Life: Diversity and Classification
Everything in the chapter on one page.
Biodiversity (12.1, 12.2)
- Biodiversity: all the variety of life.
- Endemic: found naturally in one region only.
- Hotspot: many endemics + heavy habitat loss.
- India: Western Ghats, Himalayas, Indo-Burma, Sundaland.
- Small differences add up over generations.
Classifying (12.3, 12.4)
- Group changes with the criterion (Activity 12.1).
- Criteria: external, nutrition, internal, cell, role, reproduction, DNA.
- Shared features suggest common ancestry.
- Pakke: ~300 birds, 4 hornbills, need old trees.
Systems over time (12.5)
- Aristotle: habitat, appearance.
- Linnaeus 1758: Plantae, Animalia.
- Haeckel 1866: + Protista.
- Copeland 1938: + Monera.
- Whittaker 1969: + Fungi.
Five kingdoms (12.6 to 12.6.3)
- Bases: cell type, wall, cell number, nutrition.
- Monera: one prokaryotic cell.
- Protista: one eukaryotic cell, no wall or cellulose.
- Fungi: chitin wall, absorb, decomposers; yeast unicellular.
Plantae (12.6.4)
- Thallophyta: thallus, water (Spirogyra).
- Bryophyta: rhizoids, need water (moss, Marchantia).
- Pteridophyta: true organs, xylem, phloem, no seeds (fern).
- Gymnosperms: naked seeds on cones (pine).
- Angiosperms: flowers, seeds in fruits.
Animalia (12.6.5)
- Notochord: chordata; none: non-chordata.
- Porifera cells; Cnidaria tissues, 1 opening.
- Flatworms bilateral; roundworms 2 openings.
- Annelida segments; Arthropoda jointed legs, exoskeleton.
- Mollusca soft, shell; Echinodermata CaCO3 endoskeleton.
- Protochordata; vertebrates: 5 groups.
Hierarchy and names (12.7 to 12.8)
- Kingdom, Phylum, Class, Order, Family, Genus, Species.
- Lower level: fewer members, more in common.
- Binomial (Linnaeus): Panthera tigris.
- Genus capital, species small, italic or underlined.
- Three domains (Woese 1977): Bacteria, Archaea, Eukarya.
Fossils and threats (12.9, 12.10)
- Fossils: remains in rock, sand, mud layers.
- Deeper is older and simpler.
- Threats: pollution, deforestation, overuse, climate change.
- One loss spreads to dependants.
- Purple frog, Sangai: protect habitats.
numford.com. Section numbers follow NCERT Exploration, Grade 9; the wording is our own.