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CHAPTER 8 : THE WORLD THROUGH OUR SENSES

Figure 1 : Section through the human skin

The degree of sensitivity depends on :

(i) thickness of epidermis(ii) number of receptors

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Figure 5 : Structure of the human eye Figure 6 : The mechanism of sight

Light cornea aqueous humour pupil

lens vitreous humour retina

Optic nerve brain

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Defects of Vision

Figure 7 : Short-sightedness Figure 8 : Long-sightedness

Stereoscopic and Monocular Vision

Figure 9 : Stereoscopic Vision Figure 10 : Monocular Vision

- Inability to see far objects clearly- Due to long eye balls, eye lenses

abnormally think

- Concave lenses

- Inability to see near objects clearly- Due to short eye balls, eye lenses

abnormally thin

- Convex lenses

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3.Hydrotropism 4.Thigmotropism

Nastic Movement

Sensitive to water

Root - positive hydrotropism

Shoot - negative hydrotropism

Sensitive to touch

Tendrils of plants show positive

thigmotropism.

- Movement by a plant part in response to

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CHAPTER 9 NUTRITION

Carbohydrates suppliers of energy

Divided into :

- Simple sugar (glucose, fructose,galactose)

- Complex sugar (sucrose, maltose,lactose)

Proteins2 types of proteins - animal protiens and plant

protiens

Needed for :(i) Building new cells(ii) Repairing damaged tissues(iii)Building enzymes and hormones

Figure 1 : Seven classes of food

Vitamin

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Food Test

The Human Digestive System and Process

1. Mouth (salivary glands - alkaline)Strach + water maltose

2. Stomach (gastric juice - acid)Protein + water pepton + peptide

Rennin coagulates milk

3. Duodenum (pancreas - alkaline)

amy

lase

pepsin

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Chapter 10: Biodiversity- variety of living organism in a particular area.

Living things

Plants

Flowering

+Pollination

Monocotyledons

-one cotyledon(Foodsubstances)

-parallel veins

-soft stem

-fibrous root

Dicotyledons

-two cotyledon

-network veins

-hard stem

-tap root

Non-flowering

+ reproduce by spores

Algae

-do not have stems, leavesand roots

-have chlorophyll

-spirulina

Fungi

-do not have leaves, stems,roots

-do not have chlorophyll

-yeast, mushroom, mucor

Mosses

-have leaves, stems

-do not have chlorophyll

-moss

Ferns

-have stem, leaf systems,chlorophyll

-reproduce by spores

-Fern

Animals

Invertebrates

+without backbone

aquatic/ terrestial

unjointed legs/ jointedleg

muscular feet

Vertebrates

+ with backbone

Mammals

-warm-blooed

-internalfertilization

-dolphin,whale,platypus

Reptiles

-cold-blooded

-hard and dry scales

-internal fertilization

-crocodile,lizard,snake, tortoise.

Amphibians

-cold-blooded

-gills(young),lung(fully grown)

-webbed feet

-salamandar,frog,toad

Birds

-warm-blooded

-feathers

-beak, feathers,lungs

internal fertilization

-penguin,swan

Fish

-cold-blooded

-slimy scales

-gills

externalfertilization

-sea horse

platypus

Salamander

Fern