O Level Science Notes Archives - Page 9 of 33 - Free ZIMSEC & Cambridge Revision Notes

Hydraulic brakes

By garikaib|2022-09-15T12:38:08+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Car brakes. Image driverside.com ZIMSEC O Level Combined Science Notes: Hydraulic brakes

Is another example of hydraulic machines
Pressure is applied on the brake pedal using the car driver’s foot

Car brakes. Image credit dtzone.com […]

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Immunity and Immunisation

By garikaib|2022-09-15T12:37:57+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Sindiso Marume holding her brother’s health card. Image credit irinnews.org ZIMSEC O Level Combined Science Notes: Disease:Immunity and Immunisation

Immunity-is the ability of the body to resist diseases
There are various types of immunity:

Antigen-is any substance that causes […]

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Contraception: Abstinence

By garikaib|2022-09-15T12:37:50+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Couple holding hands. Image credit neguswhoread.com ZIMSEC O Level Combined Science Notes:Contraception: Abstinence

It involves total avoidance of sexual intercourse

Adavantages

Many couples agree to wait until marriage
There is no risk of contracting Sexually Transmitted Infections
It is 100% effective
It is supported by most religious […]

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Plant pests and diseases

By garikaib|2022-09-15T12:41:52+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

A grasshopper. Image credit nutrainigridients.com A grasshopper. Image credit nutrainigridients.com ZIMSEC O Level Combined Science Notes: Plant pests and diseases

In the wild there is a balance in nature.
The are few pests and diseases that destroy plants.
In crop plants there are more pests that cause and spread disease.
This is because there […]

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Inhaled vs Exhaled air experiment: Method 1

By garikaib|2022-09-15T12:41:44+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Image credit vimeo.com ZIMSEC O Level Combined Science Notes: Inhaled vs Exhaled air experiment: Method 1

Aim: Comparing the inhaled and exhaled air.

Materials: large transparent container (e.g. bell jar), candle, tin lid, water, large basin, rubber tubing, ruler.

Method

exhaled_inhaled_air-min

Place the large […]

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Health and well being

By garikaib|2022-09-15T12:40:41+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Exercise is key to maintaining one’es health. Image credit centrictv.com ZIMSEC O Level Combined Science Notes: Health and well being

Health is the absence of disease
It is a state of being physically and psychologically well.
A person is said to be healthy […]

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Asexual reproduction

By garikaib|2022-09-15T12:40:32+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

A bud on a sugarcane cutting. Image credit 10degreesabove.com ZIMSEC O Level Combined Science Notes: Reproduction in plants: Asexual reproduction/ Vegetative reproduction

Is also known as asexual reproduction
This takes place when plants reproduce without producing seeds
Such plants have modified stems, roots or […]

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Variation

By garikaib|2022-09-15T12:40:23+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Variation in chillies. Image credit chilipapryczka.pl ZIMSEC O Level Combined Science Notes: Variation

The living world has many thousands of different types of plants and animals
For example lions are different from hyenas which in turn are different from say goats
In plants the Msasa trees are […]

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Experiment: to show that solids change shape when they melt

By garikaib|2022-09-15T12:40:14+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Melting wax takes up the shape of the container. Image credit about.com ZIMSEC O Level Combined Science Notes: An experiment to show that solids change shape when they melt