الوسم: Animal

انا حبيت اعرض ليكم معلومات عن Animal cells and plant cells

Animal cells and plant cells
Animal cells usually have an irregular shape, and plant cells usually have a regular shape
Cells are made up of different parts. It is easier to explain what these parts are by using diagrams like the ones below.

Animal cells and plant cells both contain:
• cell membrane, cytoplasm, nucleus
Plant cells also contain these parts, not found in animal cells:
• chloroplasts, vacuole, cell wall
The table summarizes the functions of these parts.

Part Function Found in
Cell membrane Controls what substances can get into and out of the cell. Plant and animal cells
Cytoplasm Jelly-like substance, where chemical reactions happen. In plant cells there’s a thin lining, whereas in animal cells most of the cell is cytoplasm. Plant and animal cells
Nucleus Controls what happens inside the cell. Carries genetic information.
In exams don’t call the nucleus the ‘brain’ of the cell. That is not a good description and will not get you marks. Plant and animal cells
Chloroplast Where photosynthesis happens – chloroplasts contain a green substance called chlorophyll. Plant cells only
Vacuole Contains a liquid called cell sap, which keeps the cell firm. Plant cells only
Cell wall Made of a tough substance called cellulose, which supports the cell. Plant cells only

Cells and their functions

Humans are multi-cellular animals. That means we are made of lots of cells, not just one cell. The cells in many multi-cellular animals and plants are specialised, so that they can share out the processes of life. They work together like a team to support the different processes in an organism.

Specialised cells
You should be able to work out special features of a cell from a drawing, if you are told what the cell can do. The tables below show examples of some specialised animal and plant cells, with their functions a
Type of animal cell Function Special features
Red blood cells
To carry oxygen • Large surface area, for oxygen to pass through
• Contains haemoglobin, which joins with oxygen
Nerve cells
To carry nerve impulses to different parts of the body • Long
• Connections at each end
• Can carry electrical signals
Female reproductive cell (egg cell)
To join with male cell, and then to provide food for the new cell that’s been formed • Large
• Contains lots of cytoplasm
Male reproductive cell (sperm cell)
To reach female cell, and join with it • Long tail for swimming
• Head for getting into the female cell
Root hair cell
To absorb water and minerals • Large surface area
Leaf cell
To absorb sunlight for photosynthesis • Large surface area
• Lots of chloroplasts