Botany Exercise 1 – Microscopy A. The Compound Microscope microscope – optical instrument consisting of a system of specially ground lenses that gives sharp‚ distinct‚ and highly magnified images of minute objects. compound microscope will be used. o two lenses: eyepiece + objective lenses o inverted image base coarse adjustment knob fine adjustment knob revolving nosepiece objective lenses stage stage clips stage opening condenser iris diaphragm mirror U-shaped platform that supports
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3.1 BIOLOGICAL MEMBRANES 3.1.1 Properties of Cell Membranes • Separates living cell from its nonliving surroundings. • 8 nm thick. • Selectively permeable - allows some substances to cross more easily than others. 4.1.2 Fluid Mosaic Model • Singer and Nicolson (1972) - plasma membrane is a mosaic of proteins dispersed within lipid bilayer‚ with only bilayer‚ the hydrophilic regions exposed to water. Hydrophilic region of protein Phospholipid bilayer Hydrophobic region of protein
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organisms fundamentally similar in structure‚ function‚ and metabolic functions Contain hereditary information passed down during cell division A cell’s volume increases faster than it’s surface area Less surface area = less are for nutrient/waste diffusion Solves via: Dividing‚ getting thinner‚ form microvilli‚ store nutrients (Microvilli – within small intestine) Cells are highly organized‚ 3 basic parts Plasma membrane Selective barrier between contents and ECF Regulates in/out Nucleus‚ usually
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Also due to the changing patterns of resistance in other bacteria to antibacterial agents‚ sensitivity studies are essential. Clinically‚ the agar diffusion method is commonly used. The organism can be reported as being sensitive‚ intermediate or resistant to an antibiotic. Sensitivity depends on the growth characteristics of the organism and diffusion characteristics of the antibiotic. Some common antibiotics used include; GRAM POSITIVE GRAM NEGATIVE Coltrimoxazole Augumentin
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IGCSE Chemistry Self-assessment practice test 1 2 6 Coloured sweets contain edible dyes. These dyes can be separated by chromatography. The diagram shows results obtained from three different orange sweets. red red yellow yellow yellow red sweet 1 sweet 2 red sweet 3 How many different red dyes were present in these orange sweets? A 4 7 B 3 C 2 D 7 Which of the diagrams shows the process of diffusion? A B C D key different atoms 8 The diagram below shows one of the changes of physical
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WHAT IS A CELL? It is the smallest unit of life that is classified as a living thing‚ and is often called the building block of life. The cell is the basic structural and functional unit of all known living organisms. Some organisms are unicellular (made of only one cell) while others are multicellular (made up of several cells). The word cell comes from the Latin cellula‚ meaning‚ a small room. The term was coined by Robert Hooke in a book he published in 1665 when he compared the cork cells he
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Potatoes The initial weights of the potato cubes ranged from 0.93-1.04 grams from the solutions containing AgNO3 (Table 1). Graph one depicts the correlation of percent change in weight for each sucrose concentration with AgNO3 added. The initial length of the potato cylinders were 2cm as depicted in table two. Graph two depicts the correlation of percent change in length in different sucrose concentrations. The initial weights for the solutions lacking AgNO3 ranged from 1.0-1.7grams (Table 3)
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molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one‚ thus equalizing the concentrations on each side of the membrane. In this experiment‚ we learn about Osmosis and Diffusion through potato cores in different concentration of sucrose‚ (water‚ .2‚ .4‚ .6‚ .8‚ 1.0). We realized that the lower the concentration‚ the higher the potato cores weighed. Introduction:All cells have membranes that are selectively permeable. In
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concentrations will have a value much smaller than the higher concentrations which will have higher values closer to 2. I predict that the rate of diffusion and ethanol concentration will be directly proportional. Method Followed the instructions that were given on the sheet (Activity 2.8). Slices of beetroot were left overnight to wash away excess dye and then placed into boiling tubes and left for 30 minutes to allow the beetroot juices to diffuse. The beetroot was then removed and we used
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peptide bonds of a protein using CuSO4 and NaOH resulting in a color change in the CuSO4 solution from purple to a darker purple color. Finally‚ the Sudan III/IV test is used to detect the hydrocarbon chains of lipids. Sudan is a red‚ non-polar‚ dye that forms hydrophobic interactions with the hydrocarbon chains of lipids. Alternatively‚ the Brown Bag test can also be used to identify lipids due to the oily nature of hydrocarbon chains. Carbohydrates: Reducing sugars and starches Reducing
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