O Level Science Notes Archives - Page 11 of 33 - Free ZIMSEC & Cambridge Revision Notes

Experiment: To show how a hydraulic Machine increases force

By garikaib|2022-09-15T12:38:07+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Syringes showing how a hydraulic machine works ZIMSEC O Level Combined Science Notes: Experiment: To show how a hydraulic Machine increases force

Aim: To show how a hydraulic machine increases force

Materials: small syringe, syringe with larger diameter, plastic tube, water, ruler

Method

Half fill the large syringe […]

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Diseases:HIV/AIDS

By garikaib|2022-09-15T12:37:56+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Zimbabwe nurse and health worker. Image credit icrc.org ZIMSEC O Level Combined Science Notes: Disease:Immunity and Immunisation

HIV and Its effects

HIV stands for Human Immunodeficiency Virus
It lives in the body fluids including blood, saliva, semen, tears etc
It enters the body in […]

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Causes of infertility

By garikaib|2022-09-15T12:37:49+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Sterility can cause strain in a relationship. Image credit colossiansfamilynetwork.org ZIMSEC O Level Combined Science Notes: Causes of infertility

Sterility is the inability to reproduce
There are a number of causes for sterility
Low sperm count (makes it […]

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Pest control

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

Tomato plant with red mite. Image credit thedemogadern.org ZIMSEC O Level Combined Notes: Pest Control

Pests cause damage to plants and spread diseases.
This results in a reduction in crop yields.
Control measures can be taken to minimise this damage.
The control measures can be either […]

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Products of digestion and the Absorption and Assimilation processes

By garikaib|2022-09-15T12:41:45+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Human nails, one of the products of assimilation. Image credit arithmaroo.com ZIMSEC O Level Combined Science Notes:Products of digestion and the Absorption and Assimilation processes

After food has been digested in can now be used.
The end products ( which would […]

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Nutrition

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

A balanced diet. Image credit healthandstylish.com ZIMSEC O Level Combined Science Notes: Nutrition

Nutrition is that branch of science that deals with nutrients and nutrition especially in humans
It is concerned with ensuring that humans are eating foods that provide necessary nutrients for health and growth
Nutrients […]

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Advantages and disadvantages of vegetative production

By garikaib|2022-09-15T12:40:31+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Sugarcane field. Image credit gov.ph ZIMSEC O Level Combined Science Notes: Reproduction in plants: Advantages and disadvantages of vegetative (asexual) production

A lot of plants which grow using the vegetative method of reproduction are able to produce seeds
They use vegetative reproduction because it has certain advantages

Advantages

New […]

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Selection
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Selection

Notes, O Level Science Notes, Ordinary Level Notes

Selection

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

ZIMSEC O Level Combined Science Notes: Selection

Each time male and female individuals reproduce they create an offspring that is different from themselves
This changes accrue over time to bring about much change in the descendants as there is inter-breeding between many individuals in each generation
This changes might result in the offspring having certain advantageous characteristics that are […]

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