•Cell structure in plants
•Cell structure in animals
•Cell structure and function
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community
Ask the community for help and clear up your study doubts
University Rankings
Discover the best universities in your country according to Docsity users
Free resources
Our save-the-student-ebooks!
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
•Cell structure in plants •Cell structure in animals ..., Study notes of Cell Biology
These are animal cells, not plant cells and their structure is different. The first difference is in scale. These cells are at x 600 – a much higher.
Typology: Study notes
2021/2022
1 / 49
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download •Cell structure in plants •Cell structure in animals ... and more Study notes Cell Biology in PDF only on Docsity!
- Cell structure in plants
- Cell structure in animals
- Cell structure and function
These are onion cells as seen under the microscope at x100. They have been stained with iodine to help certain parts of the cell to show up.
Parts -
Cell wall
nucleus
vacuole
The nucleus is a dark ‘blob’ inside each cell. Each cell has one, and only one nucleus. Its job is to control the cells activities and to store the genetic or inherited information.
Parts -
Cell wall
nucleus
vacuole
The vacuole does not show up, even with stain. It is a large, water-filled sack in the centre of the cell. It takes up most of the cell and often forces the nucleus out to the side.
These are chloroplasts.
The chloroplasts are filled with a special green chemical (pigment) called chlorophyll.
This green pigment helps the cell trap light energy for photosynthesis.
Onion cells are not green. They get no light, so do not need chloroplasts.
The chloroplasts appear mainly around the outside of the cell because the central vacuole takes up most of the space and pushes them to the outside.
These are blood cells. These are animal cells , not plant cells and their structure is different. The first difference is in scale. These cells are at x 600 – a much higher magnification than was used with the onion cells. This suggests animal cells are smaller than plant cells.
The cells do not have an obvious wall around them. Animal cells do not have a cell wall. Their outer covering is their membrane , which is much thinner than a wall. Plant cells have a membrane too, but it cannot be seen as it is pushed right up against the inside of the much thicker wall.
All cells have a structure which is suited to its function.
These are nerve cells.
They have many side branches to connect to other cells, and so pass on information in the form of tiny electrical signals.
These are muscle cells. In order to carry out their function, muscle cells are able to contract. This is how muscles pull on bones to make you move. The individual cells are organised together into fibres.
These are skin cells at x100. At this magnification the cells are too small to make out individually, but the nuclei show up as tiny dots. The cells are arranged into different layers within the skin.
Back to the blood cells…
There are two types – red cells are filled with a chemical called haemoglobin. This chemical lets them carry oxygen. Red blood cells are the only cells which have no nucleus – it disintegrates as soon as the cells are formed.
Red cell
These cells are bad news. This slide shows many very small cells all packed together. This is because these cells are dividing, then dividing , then dividing … they are dividing out of control. These are cancer cells, which form a tumour, a clump of cells dividing out of control.