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• cell membrane, mitochondria, ribosomes, cytoplasm and nucleus are all in animal and plant cells
• plant cells also include a vacuole, chloroplasts and a cell wall
• vacuole - contains cell sap
• chloroplasts - site of photosynthesis
• cell wall - supports cell, strengthens it
• ribosomes - site of protein synthesis
• mitochondria - site of aerobic respiration, where most of the energy is released
• cell membrane- controls what enters and leaves the cell
• cytoplasm- where chemical reactions occur
• nucleus - controls the cell and has DNA
• Prokaryotic cells - have no nucleus, mitochondria or ribosomes and are smaller than eukaryotic cells
• image size= magnification x actual size
• light microscope is cheaper and easier to use than an electron microscope
• an electron microscope has better magnification and resolution than a light microscope
• cells that count as specialized cells are : fat cells, white blood cells, phloem and xylem cells
• embryonic stem cells can become any cell
• adult stem cells can become most but not all cells
• diffusion and osmosis are passive forms of cell transport
• osmosis is water particles going through a partially permeable membrane from a high concentrated area to a low concentrated are
• Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
• nucleus has chromosomes which are made from DNA
• human cells contain 23 pairs of chromosomes, 46 in total
• chromosomes carry genes which determine characteristics
• cells can divide by mitosis or meiosis
• mitosis is when a cell divides to produce two identical daughter cells
• gas exchange in the lungs is an example of diffusion
• in the large intestine, water being absorbed from food into the blood is osmosis.
• factors that affect cell transport include : surface area, temperature and short diffusion pathways