01 Introducing Biology

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Introducing Biology


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What is Biology?

organisms study of=


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Different fields in biology

Botany

Zoology

Microbiology

Cytology

Anatomy

Genetics

Ecology


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Why study biology?

To help develop scientific thinkingskills

To understand how biology is appliedin daily life

Better understanding of biology-related social issues

Prepare for a future career


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What are organisms?

All organisms have sevencharacteristics in common


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Nutrition

Process of obtaining food

Functions of food:

To release energy by respirationAs raw materials for growth

To keep organisms healthy

Green plants: by photosynthesis tomake food

Animals: depend on other organismsfor food (i.e. to eat other organisms)


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Respiration

The process of releasing energyfrom food to support daily activities

Aerobic respiration : requires oxygenAnaerobic respiration : does notrequire oxygen

Food + OxygenCarbondioxide + Water

+ Energy


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Movement

Movement in animals:

Can move from place to place

Locomotion

Fast

Purposes of locomotion:

To find food and mates

To find place to liveTo escape from enemies and dangers


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Movement

Movement in plants:

Cannot move their whole bodies

Cannot move from place to place

By growth

Slow

Purposes of movement in plants:

To get more sunlight for photosynthesis

To reach more water for absorption


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Growth

Increase in size

Increase in complexity

Irreversible

Animals grow faster than plants

Animals

occur all over the body

stop growing when reached a certain size

Plants

occur at only some regions of the bodythroughout their lives


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Irritability(Sensitivity)

To detect changes from theenvironmentTo detect stimuli from theenvironment

To make suitable responses to the

changes

Animals: to make responses quicklyby movement

Plants: to make responses slowly bygrowth


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Reproduction

To produce offspring similar to theirparents

To enable them to continue to existthrough generations

To avoid extinction

May involve one or two parents


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Excretion

The removal of metabolic wastesproduced by the body

Metabolic wastes are harmful whenaccumulated

Metabolic wastes include:

Carbon dioxide

Urea

Faeces

Not producedby the body


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Excretion

Animals remove metabolic wastes by:

sweating

breathing out

urination

Plants remove metabolic wastes by:

turning them into harmless substances

storing them into leaves and removethem when the leaves fall


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Nature of science

The world is understandable

People can discover patterns in all ofnature


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Nature of science

Scientific ideas are dynamic andsubject to change

New discoveries may challenge

preexisting theories


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Nature of science

Scientific knowledge is durable

Modification of ideas is the norm inscience


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Nature of science

Science cannot provide completeanswers to all questions


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Scientific method

Making observations

Proposing a hypothesis

Doing experiments

Drawing conclusions

Making predictions

Asking questions

If the hypothesisis rejected


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Experimental and control set-up

Control set-up

Same as experimental set-up

but the factor under investigation is

absent


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Variables

Independent variablecan be manipulated during theexperiment

Dependent variablecannot be manipulated during theexperiment

its change is caused by the change in

the independent variable during theexperiment

Controlled variablemaintained constant throughout the

experiment


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Observation


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Asking question


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Proposing hypothesis


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Making prediction


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Doing experiments

Independent variable

Presence / absence of cover

Dependent variable

Presence / absence of flies

Controlled variables

Size of meat used

Kind of meat used

Size of jar used

Temperature

Time


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Doing experiments

Experimental set-up


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Doing experiment

Control set-up


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Drawing conclusion


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Forwarding questions

Does this experiment REALLYsupport his hypothesis??

i.e. are there any mistakes in thedesign of the experiment that may notallow the result obtained to draw theconclusion he wants?


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Homework: P.9 Practical 1.1

The homework should include:

Independent variable

Dependent variable

Controlled variables (at least 3 examples)

Steps (You should have experimentaland controlled set-up)

01 Introducing Biology

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