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How are cells structured? Learn about the size and function of plant and animal cells for GCSE Combined Science, AQA.
- Comparing Sizes
GCSE; AQA Trilogy; Cell structure - AQA Comparing sizes....
- Eukaryotes and Prokaryotes
Eukaryotic cell: Prokaryotic cell: Size: Most are 5 μm – 100...
- Plant and Animal Cells
GCSE; AQA Trilogy; Cell structure - AQA Plant and animal...
- Video
Cell structure - AQA Video. Organisms are made up of cells....
- Comparing Sizes
- Cell Wall
- Plastids
- Central Vacuole
- Cell Membrane Or Plasma Membrane
- Endoplasmic Reticulum
- Golgi Apparatus
- Microfilaments Or Actin Filament
- Microtubules
- Intermediate Filaments
- Mitochondria
It is the outermost, protective layer of a plant cell having a thickness of 20-80 nm. Cell walls are made up of carbohydrates such as cellulose, hemicellulose, and pectin and a complex organic polymer called lignin.
They are double membrane-bound organelles that have their own genetic material. Plastidsare mainly of three types: a) Chloroplasts: Found in the green parts of a plantand algae that contain the photosynthetic pigment, chlorophyll. b) Leucoplasts: Found in the non-photosynthetic tissues of plants. c) Chromoplasts: Colored plastics found in fruits an...
It is the large vesicle that make up almost 30 to 80% of the total plant cell volume. The central vacuoleis often the largest organelle in the cell that is filled with fluid, ions, enzymes, and other molecules. Apart from plants, they are also present in algae.
It is a thin, biological membrane having a thickness of 7.5-10 nm that separates the interior of the cell from the outside environment. The plasma membrane is selectively permeable in nature, which is mainly composed of lipids and proteins, with some carbohydrates attached to them.
It is a series of membranes within the cytoplasm that forms connections with the nucleus on one side and cell membrane on the other. It is of two types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). The surface of RER has ribosomesattached to it, while they are absent in SER.
Also known as Golgi body or Golgi complex, they are stacks of five to eight membrane-covered sacs called cisternae. The Golgi apparatus acts as the post office of the cell by packaging and transporting proteins from their source RER to their destination.The number of Golgi apparatus varies in cells according to their functions.
They are a network of long and thin protein fibers present in the cytoplasm of the cell having a diameter of 3-6 nm. Microfilamentsare composed of actin proteins that make them extremely strong and flexible.
They are fibrous hollow rods composed of proteins called tubulin. Microtubuleshave an outer diameter of 23-27 nm and an inner diameter of about 11-15 nm. They can grow to as long as 50 µm and thus are highly dynamic.
They are made up of two proteins forming a coiled-coil structure. Intermediate filaments have a diameter of 8-10 nm that are intermediate in size to microfilaments and microtubules. Microtubules, together with microfilaments and intermediate filaments, form the cytoskeletonof the cell.
It is a rod-shaped double membrane-bound organelle that contains its own DNA and ribosomes. Mitochondria are often called the ‘powerhouse of the cell‘, producing ATP that drives all cell-based metabolic activities.
Learn about the ultrastructure and organelles of animal, plant, fungal and bacterial cells. BBC Bitesize Scotland revision for SQA National 5 Biology.
The basic structure of a plant cell is shown below. Photosynthesis relies on many structures in the cell all working together, each playing its role. The diagram below shows the same plant...
The process of double fertilisation in plants, in which one male nucleus fuses with the two polar nuclei to form the triploid endosperm nucleus and the other fuses with the egg cell to form the diploid zygote. Examiner Tip. Students often get confused between pollination and fertilisation in plants, but they are not the same thing.
Jun 11, 2004 · In this review, I will outline the present state of knowledge, focusing on molecular and genetic mechanisms revealed in work on Arabidopsis, specifically in three areas: the integration of floral induction signals by a small group of floral integrators, the activation of the floral organ identity genes by the floral meristem identity genes, and ...
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Mar 7, 2024 · The most common specimens to observe under a light microscope are cheek cells (animal cells) and onion cells (plant cells) A stain is often used to ensure cell structures are clearly visible under the microscope.
