KS3 Science Flashcards
1-21= Section 1
Microscopes
Microscopes are used for looking at objects that are too small to see with the naked eye. The lenses in the microscope magnify object(makes them look bigger) so that you can identify them.
What are the parts of a microscope?
Eyepiece lens
Body tube
Rough focusing knob
Fine focusing knob
Handle
High power objective lens
Low power objective lens
Stage
Mirror
The steps
How to use a Microscope?
- Carry by the handle.
- Place it near a lamp or a window, and angle the mirror so the light shines through the hole in the stage.
- Stick the object(s) to the slide which is them clipped to the stage.
- Select the lowest powered objective lens.
- Turn the rough focusing know and move the objective lens down to just above the slide.
- Look down at the eyepiece lens and adjust the focus using the fine focusing knob.
- Keep adjusting until you get a clear image of whatever’s on the slide.
- If you need to see the slide with greater magnification switch to a higher powered objective lens.
- Now refocus the microscope.
- Repeat steps 5-7
What is another word for a living thing?
An organism
What are organisms made up of?
All organisms are made up of tiny building block known as cells.
Can cells be seen?
Cells can only be seen with a microscope. But you have to stain them with a coloured dye.
What are the parts of an animal cells?
Nucleus
Cytoplasm
Mitochondria
Cell membrane
What does a plant cell have?
Nucleus
Cytoplasm
Mitochondria
Cell membrane
Cell wall
Vacuole
Chloroplasts
What do only animal cells have?
Cell wall
Vacuole
Chloroplasts
What do both plant and animal cells have?
Nucleus
Cytoplasm
Mitochondria
Cell membrane
What is a Nucleus?
It controls what the cell does.
What is a cytoplasm?
This is jelly-like stuff where most chemical reactions happen.
What is a cell membrane?
This is a thin skin around the cell- it holds the cell together and also controls what goes in and out of the cell.
What are the mitochondria?
These are tiny structures inside the cell where most of the chemical reactions for anaerobic respiration take place. Respiration releases energy for the cell.
What is a cell wall?
A rigid outer coating made of cellulose- it gives support to the cell.
What is a Vacuole?
This is filled with cell sap- a weak solution of sugar and salts.
What are Chloroplasts?
This contains chlorophyll used for photosynthesis. Photosynthesis makes food for the plant.
What does multicellular mean?
It means to be made up of lots of cells. Such as animals and plants.
What does unicellular mean?
To be made of one cell. These cells have adapted to help them survive in the environment they live in.
What is a Euglena?
Euglena live in the water. They have a tail-like structure called a flagellum to help them swim.
What is an Amoeba?
Some amoeba live in the water. They use a contractile vacuole to collect any excess water inside them and squeeze it out at the cell membrane.
How are cells organised?
In organisms with lots of cells (like animals and plants), the cells are organised into groups.
What are the categories of cell grouping?
Similar cells make a tissue. Different tissues make an organ. Groups of organs make an organ system. Several organ systems make an organism.
What is an example of plant groupings?
A Palisade cell makes up a palisade tissue which makes up a leaf which make up the shoot system.
