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Obtaining and Utilization Food Class 7 Science Solved question (Basic Science Questions answers)

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A. Answer these questions 1. Name the three life process help living being to procure energy from food? Answer: Three life processes that help living organisms to procure energy from food are: (i) Digestion (Nutrition) (ii) Respiration (iii) Transportation 2. What are Autotrophs? Name an organism other than other than green plant that is an autotroph. Answer: Autotrophs are organisms that can prepare their own food. Chlamydomonas is a type of green algae which is an example of an autotroph, other than green plants. Cyanobacteria are also an example of autotroph. 3. Name three type of heterotrophic nutrition Answer: Three types of heterotrophic nutrition are: (i) Saprophytic nutrition (ii) Parasitic nutrition (iii) Holozoic nutrition 4. What are enzymes? Answer: Enzymes are chemical substances that act as biological catalysts and are important for carrying out biochemical processes, such as digestion, in our body ...
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Class9 Biology chapter Cell the Fundamental unit of life :Assignment solved

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1. What is plasma membrane? What are their functions? Ans: Plasma membrane also called as cell membrane, is the outer covering of a cell that separates the cell contents (protoplasm) from the surrounding medium. It is made up of proteins and lipids. It gives form (shape and size) to the cell It maintains the individuality of the cell (i.e. seperates cells) It keeps the cell contents in place 2. What are cell organelles ? Ans: The certain specific living parts of a cell with a definite function are celled Cell organelles. All cell are found to have same organelles and together these constitute to the basic unit of life. 3. What is cellulose and its functions? Ans: Cellulose is the main component of a plant cell wall. It is responsible for giving structural shape to the cell and also to protect the protoplasm. 4.  What is a Prokaryotic cell? Give an Example. Ans: The cells that do not hav...
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8th Class Cell structure and function solved questions(Biology)

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Q  Name the cells having branches structure. Ans Nerve Cell. Q Why cells could not be observed before seventeenth century? Ans Cells could not be observed before seventeenth century because till that time microscope was not invented. Q Why plant cell have cell wall? Ans Plant cells need protection against variations in temperature, high wind speed, atmospheric moisture, etc. They are exposed to these variations because they cannot move. That's why they have cell wall. Q Which organism has the smallest cell? Ans  Mycoplasmas, a bacteria has the smallest cell of the size of 0.1 micron i.e. ten thousandth part of a mill metre. ' Q  Which is the largest cell visible by unaided eye? Ans Ostrich egg has the largest visible cell by unaided eye. Q Name the four elements, which fonn major part of protoplasm. Ans These are carbon, hydrogen, oxygen and nitrogen. Q Give two examples of prokaryotes. Ans Bacteria and blue green algae. Q  Name the la...
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Derivation of Lens and mirror formula X Reflection and Refraction of light

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MIRROR FORMULA The relation between object distance(u), image distance(v) and the focal length (f) of the mirror is known as MIRROR FORMULA. Consider a concave mirror MM' (of small aperture). An object AB of height h is placed on the left of the mirror beyond its center of curvature so that the image formed is real, inverted and diminished in size(height = h'). Here : Object distance = PB = -u Image distance = PB'= -v Focal length = PF = -f Radius of curvature = PC = -R As shown in Figure, Ī” ABP āˆ¼ Ī” A'B'P. āˆ“ A'B'/AB = PB'/PB āˆ“ A'B'/AB = (-v)/(-u) āˆ“ A'B'/AB = v/u.............(I) Similarly, as shown in the figure, Ī” ABC āˆ¼ Ī” A'B'C. āˆ“ A'B'/AB = CB'/CB āˆ“ A'B'/AB = (PC-PB')/(PB-PC)........[as CB'=(PC-PB') and CB=(PB-PC)] āˆ“ A'B'/AB = [-R - (-v)]/[-u - (-R)] āˆ“ A'B'/AB = (-R + v)/(-u + R)........(II) By (I) & (II), v/u = (-R + v)/(-u + R) āˆ“ -...
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CBSE:10th Math :Chapter Triangles : Solved Concept builder theorems

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If a line divides any two sides of a triangles proportionally then the line is parallel to the third side Statement:   If a line divides any two sides of a triangles proportionally (in same ratio), then the line is parallel to the third side. Proof:   We are given ABC   AD / BD = AE / CE We have to prove: DE is parallel to BC Let DE's not parallel to BC then an another line DE' is parallel to BC. Now AD / BD = AE / CE [Given] And AD / BD = AE' / CE' [ Thales Theorem ] Therefore AE / CE = AE' / CE' i.e. AE / CE + 1 = AE' / CE' + 1 i.e. AE + CE / CE = AE' + CE' / CE'   i.e. CE = CE' But this is not possible until E and E' is coincident. Thus, our assumption is wrong and DE is parallel to BC. X Triangles :Criteria for Similarity of Triangles Solved:    10th math Triangles Thales theorem   10th math Converse of Thales theorem   Angle bisector theorem   10th math SAS similarity of triangle 10th SSS similarit...
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