BIT Assignment

By CHAN Wai Kay

9th June, 2000

Diversity of Organisms and Classification

Classification of OrganismsKingdom

Phylum / Division

Class

Species

Species

• The smallest group of organisms classified which can interbreed with each other to produce fertile offspring

Two Kingdom System

• Animals

• Plants

Animal Kingdom

• Divided into two groups according to the presence or absence of backbone:– Invertebrates : without backbone– Vertebrates : with backbone

Invertebrates

Invertebrates

Invertebrates

Vertebrates

• Divided into 5 groups:– Fish– Amphibians– Reptiles– Birds– Mammals

Fish• Aquatic

• Cold-blooded

• Body covered with slimy and wet scales

• Streamline body for easy movement through water

• Fins for balance and to control movement

• Gills for breathing

• External fertilization

Amphibians• Cold-blooded

• Scaleless, moist skin

• With 4 Limbs

• Larvae (tadpoles) use gills for breathing; adults use lungs

• External fertilization

Reptiles

• Cold-blooded

• Body covered with hard, dry scales

• Live on land

• Breathe with lungs

• Internal fertilization; lay shelled eggs

Birds

• Warm-blooded

• With feathers and wings

• Beak for feeding

• Lungs for breathing

• Internal fertilization; lay shelled eggs

Mammals• Warm-blooded

• Hairs on skin

• Females have mammary glands for producing milk

• Lungs for breathing

• Diaphragm present

• Internal fertilization; embryos develop inside mothers’ bodies

Summary -- Body Covering of Vertebrate

Fish Moist scale

Amphibians Naked moist skin

Reptiles Dry scale

Birds Feather

Mammals Hair

Activities

• You may examine the real specimens displayed.

• Homework– Textbook Page 39 HKCEE 1989 5(b)

Plant Kingdom

• Can be divided into two groups:– Non-flowering plants– Flowering plants

Non-flowering plants

• 5 groups:– Fungi– Algae– Mosses– Ferns– Gymnosperms

Fungus kingdom• Made up of hyphae

• No root, stem and leaf

• No chlorophyll– Saprophytic or parasi

tic

• Reproduce by forming spores

Algae

• Mostly aquatic

• May be unicellular or multicellular

• No root, stem or leaf

• Contain photosynthetic pigments (e.g. chlorophyll) for photosynthesis

Mosses

• With simple leaves and stems

• No root; with rhizoids for anchorage and absorption of water

• Reproduce by spores

• No vascular tissues

• Found in damp area

Ferns

• With true roots, stems, leaves and vascular tissues

• Reproduce by spores

• Live in damp places

Gymnosperms• With true roots, stems,

leaves and vascular tissues• Reproduction by

producing seeds– Seeds develop in cones, not

enclosed by fruits naked seeds

• Needle-shaped leaves to reduce water loss

Angiosperms (Flowering plants)

• With true roots, stems, leaves and vascular tissues

• With flowers for reproduction

• Seeds are produced inside the fruit (matured ovary)

SummaryChloroplyll True root,

stem & leafSeed Flower

Fungi X X X X

Algae X X X

Mosses X X X

Ferns X X

Gymnosperm X

Floweringplants

Remarks

• In Form 6/7, Fungi are grouped into a Kingdom by themselves. They are not considered as plants.

• In Form 4/5, bacteria are grouped under Fungi. In Form 6/7, bacteria are grouped into a Kingdom by themselves.

Activities

• You may examine the real specimens displayed.

• Homework– Textbook Page 37-38, HKCEE 1985 1(a) and

HKCEE 1987 1(a)