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Dear students, prepare for biology class 9th chapter 4 long questions. These important long questions are carefully added to get you best preparation for your 9th class biology ch. 4 exams.
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Our database contains a total of 0 questions for biology Short Questions. You’ll prepare using this huge databank.

Question: 1
Describe the types of microscopes.
Answer: 1
Question: 2
Describe the history of formulation of cell theory?
Answer: 2
Question: 3
Construct the time line that traces the history of formulation of the cell theroy.
Answer: 3
Question: 4
Write a note on Cell wall.
Answer: 4
Ans. Cell Wall Introduction The cell wall is a non-living strong component of the cell and it is located outside the plasma membrane. Not all living organisms have cell walls around their cells e.g., animals and many animal like protists. Function It provides shape, strength, protection and support to the inner living matter (protoplasm) of the cell. Chemical composition Plant cells have a variety of chemicals incorporated in their cell walls. Types Primary wall (Lahore board 2012 G II) The outer layer of the plant cell wall is known as primary wall and the cellulose is the most common chemical in it. Secondary Wall (Lahore board 2012 G II) Some plant cells, for example xylem cells also have secondary walls on the inner side of the primary wall. It is much thicker and contains lignin and some other chemicals. Plasmodesmata There are pores in the cell walls of adjacent cells, through which their cytoplasm is connected. These pores are called plasmodesmata. Cell wall of Fungi Fungi and many other protists have cell walls although they do not contain cellulose. Their cell walls are made of variety of chemicals. For example, chitin is present in the cell wall of fungi. Cell wall of prokaryotes Prokaryotes have a cell wall composed of peptidoglycan that is a complex of amino acids and sugar.
Question: 5
Write a note on Cell membrance.
Answer: 5
Question: 6
Write a note on nucles.
Answer: 6
Question: 7
Write a note on Plastids.
Answer: 7
Question: 8
Write the relationship between cell size and shape and surface area to volume ration.
Answer: 8
Ans. Relationship between cell size and shape Cells vary greatly in size. Smallest Cells The smallest cells are bacteria called Mycoplasmas with diameter between 0.1gm to 1.0pm. Bulkiest Cells The bulkiest cells are bird eggs. Longest Cells Longest cells are some muscle cells and nerve cells. Most cells lie between these extremes. Relation of cell size and shape to cell function Birds Egg Bird's eggs are bulky because they contain a large amount of nutrient for the developing young. Muscle Cells Long muscle cells are efficient in pulling different body parts together. Nerve Cells Lengthy nerve cells can transmit messages between different parts of body. Benefits of small cell size Small cell size also has many benefits. For example human red blood cells are only 8t_tm in diameter and therefore can move through our tiniest blood vessels i.e. capillaries. Surface area of large and small cells Large cells have less surface area in relation to their volume while small cells of the same shape have more surface area. The figure shows relationship using cube shaped cells. The figure shows one large cell and 27 small cells. In both cases the total volume is the same: Volume = 30p.m x 30p.m x = 270001=3 Contrast or Comparison of total volume to total surface area In contrast to the total volume, the total surface area are very different because the cubical shape has 6 sides. Its surface area is 6 times the area of 1 side. The surface areas of The cubes are as follows. Surface area of 1 large cube = 6 x (301= x 3011m) = 5400p,m2 Surface area of 1 small cube = 6 x Surface area of 27 small cubes = 27 x 600p.m2 = 162001= Role of Surface Area The need of nutrients and rate of waste production are directly Proportional to cell volume. The cell takes up nutrients and excretes wastes through its surface cell membrane. So a large volume cell demands large surface area. A large cell has much smaller surface area relative to its volume than smaller cells have. Hence it is concluded that the cell membrane of small cells can serve their small volumes more easily than the membrane of the large cell.
Question: 9
Descirbe the passage of molecules into and out of cells.
Answer: 9
Question: 10
Describe Different types of animals tissues.
Answer: 10
Question: 11
Q<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857376594001076335476"> )</gwmw> 5) a Write a note on <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857376556141678435537">meristematic</gwmw>Tissuses?
Answer: 11
There tissues are composed of cell. Which have the ability to divide the cell are thin walled have <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857374406754740972403">large nucleus</gwmw> and small or no values<div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857374720185790243561">Apicla</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857374619746293051484">meristerms</gwmw>:</div><div> Located at the apices of roots and <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857374889967046228227">shoot</gwmw>. When they <gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857375427670550220806">divide they</gwmw> cause <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857375427676002714548">increase</gwmw> in the length of plant such growth is called primary growth</div><div>Lateral <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857376164948252516556">meristerns</gwmw>:</div><div><br></div><div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857377257567109905005">are</gwmw> located on the lateral sides of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857377257564632985749">roats</gwmw> and shoat by dividing they are responsible for increase in growth is called secondary growth.</div><div>Vascular cambium: Located between xylem and phloem and cork <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857378171372291066616">combium</gwmw>in <gwmw class="ginger-module-highlighter-mistake-anim ginger-module-highlighter-mistake-type-3" id="gwmw-15857378388709539602433">the the</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857378263123328146641">auter</gwmw>lateral sides of <gwmw class="ginger-module-highlighter-mistake-anim ginger-module-highlighter-mistake-type-3" id="gwmw-15857378388708501607597">planet</gwmw></div>
Question: 12
Q NO 5<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857379101724271126350">(</gwmw>B) What <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857379101727116785915">is diffusion explain</gwmw> with examples?<div><br></div>
Answer: 12
A Diffusion is the movement of molecules from an area of higher concentration <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857403308062065487195">to</gwmw> the area of lower concentration along concentration the <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857402492027655269994">malecules</gwmw>of any substance are in motion when that <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857403308060101856185">substances</gwmw> is above 0 degree centigrade. In substance, <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857405705205187043729">majority</gwmw> of the molecules move from higher to lower <gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857405705213918906277">concentraion although</gwmw> there are some that move law to high the overall movement is thus from high to <gwmw class="ginger-module-highlighter-mistake-type-2" id="gwmw-15857405705212994031845">law</gwmw> concentration. Eventually the molecules reach a state of equilibrium where they are distributed equally throughout the area Diffusion is one principle method of movement of substance within <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857407167601043786045">cell</gwmw> as well as across well membrane<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857407167606865413496"> .</gwmw> Carbon, dioxide, oxygen, glucose etc. <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857409086545701356041">can</gwmw> cross <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857409086543031179962">cell wall membrain</gwmw> by diffusion<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857409086540839290970"> .</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857412274269288847421">example</gwmw> of diffusion Because a cell does not expend energy when molecules diffuse across its membrane the diffusion is <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857412274264830951072">type</gwmw> of passive transport.
Question: 13
Q no 6 (a) Describe the cell function and cell structure?
Answer: 13
The bodies of animals and plant are made of different cell type each type performs <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857414829073274909607">specific function</gwmw> and all coordination function became the life processes of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857414829071982489541">organisns</gwmw>cells may one type may differ from those of <gwmw class="ginger-module-highlighter-mistake-type-2" id="gwmw-15857414829077786200728">other</gwmw> type in the following respects<div>Size and Shapes:</div><div> Red blood <gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857415429778223122561">cell are</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857415429774822184061">round</gwmw> to accommodate globular hemoglobin.</div><div>Nerve cells are long for the transmission of nerve impulse.</div><div>Xylem cell are tube -like and have thick wall of conduction of water and support.</div><div>Surface <gwmw class="ginger-module-highlighter-mistake-type-2" id="gwmw-15857416523792754762535">are</gwmw> to volume ratio:</div><div> Root hair cell <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857416854549664570953">have</gwmw> large surface area of the maximum absorption of water and salts.</div><div>It <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857417803938293790275">on</gwmw> be <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857417803935689594315">explain</gwmw> by the following examples of cell of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857417803939735682909">human body</gwmw>.</div><div>Never cell conduct nerve impulse and thus contribute in coordination in <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857433805791220097620">body</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857433805808122160439"> .</gwmw><gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857434338485010807612">Muscle cell</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857434338489600542339">undergo</gwmw> contraction and share their <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857434185543852582081">rale</gwmw>in movement in <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857434338490119875410">body</gwmw>.</div><div>Red blood cell carry oxygen and white blood cell kill foregin materials and So contribute in the rules of blood in transportationand defense<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857435329571246911948"> .</gwmw></div>
Question: 14
Q no 6 (b) Describe the structures and function of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857439153463844989312">nucleus</gwmw>?
Answer: 14
Organelles are small structures within cells that perform dedicated function<div>NECLEUS:</div><div> A prominent nucleus <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857442504910674260511">occur</gwmw> in <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857442504917768710505">eukaryrtic cell</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857442504912700286438">,</gwmw> In <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857442504919413244227">animals</gwmw> cell it is present in the center while in mature<gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857442504911830003873">plants</gwmw> cells<gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857442504919818169756"> .</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857443078876058717031">due</gwmw> to the formation of large central <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857442985473750338438">vaciuale</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857443078876160636115">.</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857443940477180718870">it</gwmw> is pushed to side nucleus is bounded by a double membrane know as nuclear <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857443855502565693869">envelape</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857443940486372243944">.</gwmw> Nuclear envelope <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857444464756830431054">contain</gwmw> many small pores that enable it to <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857444332902529423475">actt</gwmw>as a semi-permeable membrane</div><div>Nucleolus:</div><div> <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857475184924540281675">Nucleolus</gwmw> is dark spot and it is the site where <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857474088208724037753">ribosome</gwmw> RNA are formed and assembled as <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857473468218523087904">ribosome</gwmw>chromosome are visible only during cell <gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857475184924035131564">division while</gwmw> during <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857474565737746675351">interphase</gwmw>of cell they are in the form of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857475184929189633889">fine thread-likestructure</gwmw> known as <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857475228667216274563">chromation</gwmw></div><div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857475600162790042434">the</gwmw>prokaryotic cells do not contain prominent nucleus.</div><div><br></div><div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857478567482296336361">their</gwmw> chromosome is made of 'DNA only<span style=""> </span>submerged cytoplasm</div>
Question: 15
Q no 7 (a) Write a <gwmw class="ginger-module-highlighter-mistake-type-2" id="gwmw-15857479630634556260259">shot</gwmw> note on Lysosomes:<div><br></div>
Answer: 15
In the mid- twentieth <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857500932761562451710">untury</gwmw>a <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857501012562659172586">belgion</gwmw>scientist <gwmw class="ginger-module-highlighter-mistake-type-2" id="gwmw-15857503585034374285952">christian</gwmw> Rene <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857501250185830745815">de</gwmw><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857503585036379291224">duve</gwmw>. <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857501588832748298939">discovered</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857501535019227043247">lysosomes</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857501588831293504977">.</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857505155237841284788">these</gwmw> are single membrane bound-<gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857505155232234962343">organielles</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857502165059041135071">lysomes</gwmw> contain strange digestive <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857502378567332102330">emymes</gwmw>and work for the breakdown of focal and waste materials within <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857505155233531381112">cell</gwmw> during its function a <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857504506903938844558">lusome</gwmw><gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857505155231651503233">fuses</gwmw> with the <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857504642305362750457">cacuole</gwmw>that contain the <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857504760424266130213">tergeted</gwmw>materials and its <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857504967843301740442">eneymes</gwmw><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857505035043402312323">breake</gwmw>down the materials
Question: 16
Q no 7 (b) Write note on mitochondria and endoplasmicreticulum?
Answer: 16
<gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857511953248258254064">Mitocnoridria</gwmw> are double membrane-bounded structure formed only <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857508989183895573670">ineukaryotes</gwmw>.<div>These are the sites of <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857509097338578426274">aerabic</gwmw> respiration. <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857510619813146295721">and</gwmw> are the major <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857509254360921986015">eergy</gwmw>production center the outer <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857509458600788191662">membrance</gwmw>of a<span style="">Mitocnoridrian</span> <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857510757926355963710">is</gwmw>small</div><div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857512799037402274417">but</gwmw> the inner membrane forms many <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857511398768884301904">infalding</gwmw><span style="">Mitocnoridria</span>have their own DNA and <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857512764294912844881">ribosemes</gwmw><gwmw class="ginger-module-highlighter-mistake-type-6" id="gwmw-15857512799031156807221">.</gwmw> The <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857512858531980932984">ribosomes</gwmw>of <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857512948639534048083">mitochoridrion</gwmw>are <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857512972003056336478">moe</gwmw>similar to <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857513325879774691428">bacterial ribosome</gwmw>to bacterial ribosome</div><div><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857513474481019482247">Endoplamic</gwmw></div><div> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857515956075198794499">Ensoplamic</gwmw><gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857515225461563174405">rericulum</gwmw> is a network of <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857515287035042755061">intercounted</gwmw><gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857515956076598829110">chamnels</gwmw>that extends from cell membrane to <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857515956079298742008">nuclear encelop</gwmw>. The network <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15857516124572623529736">exist</gwmw> in two forms</div><div>Rough Endoplasmic Reticulum:</div><div> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857517346813181790659">is</gwmw> so named because of its rough appearance due to numerous <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857516901596979168221">ribosomes</gwmw> that are attached to it</div><div>Smooth <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857517427676815183855">endoplasmic</gwmw>Reticulum:</div><div><gwmw class="ginger-module-highlighter-mistake-anim ginger-module-highlighter-mistake-type-1" id="gwmw-15857518140724728797004">Lackes</gwmw> <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857517682544562363807">ribosomes</gwmw>and is <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857517759863029681225">inaleved</gwmw>in lipid <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15857517894229672081894">metabrlism</gwmw>and in the transport of materials from one part of cell to <gwmw class="ginger-module-highlighter-mistake-anim ginger-module-highlighter-mistake-type-2" id="gwmw-15857518140720013105343">other</gwmw></div>
Question: 17
Define micrscopy . What are characteristics of a microscope ? What are types of microscope ?
Answer: 17
Microscopy :<div>The use of Microscope is known as microscope . The first compound microscope was developed by Zacharias Janssen , in Holland in 1595 . It was simply a tube with lenses at each and its magnification ranged from 3X TO 9X</div>
Question: 18
What is light microscope ?
Answer: 18
Light microscopeworks by passing visible light through the specimen<div>Construction :</div><div>It uses two glass lenses . One lens produces an enlarged image of the specimen and the second lens magnifies the image and projects it into viewer's eye or onto photographic film</div>
Question: 19
What is electron microscope ?
Answer: 19
Electron microscope :Electron microscope is the most advanced form of microscope<div>Construction :</div><div>In EM , object and lens are placed in a vacuum chamber and a bean of electrons is passed through object . Electrons pass through or are reflected from object and make image . Electromagnetic lenses enlarges and focus the image onto a screen or photographic film</div><div><br></div>
Question: 20
Explain the history of cell theory .
Answer: 20
Aristotle : He presented the idea that all plants and animals are somehow related<div><br></div><div>Robert Hooks :In 1665 , he examined a thin slice of cork and observed many tiny empty compartments are called cellulose . So He discovered cell</div><div><br></div><div>Antonie van Leeuwenhoek :He observed micro-organisms in pond water by his self-made microscope and called then animalcules</div>
Question: 21
What are sub-cellular and acellular particles ?
Answer: 21
According to the first principle of the cell theory all organisms are composed of one or more cells . Virus ,prions and viroids are not composed of cells , rather they are sub-cellular or a cellular particles . They do not run any metabolism inside them . They show some characteristics of living organisms i-e they can increase in number and can transmit their characters to next generation . We knows that such acellular particles are not classified in any of the five kingdoms of organisms
Question: 22
What are the principle of cell theories ?
Answer: 22
1: All organisms are composed of one or more cells<div>2: Cells are the smallest living things , the basic unit of organization of all organisms</div><div>3: Cells arise only by divisions in the previously existing cells</div>
Question: 23
Explain the following cellular structure
Answer: 23
1: Cell wall : Cell wall is a strong and non-living component of cell present outside the plasma membraneFunction : It provides shape , strength , protection and support to the inner living matter called protoplasm cellsPresence : Cell wall is present in plants , plant like protists , fungi and prokaryote but absent in animals and animal like protists
Question: 24
Write a note on cell organelles?
Answer: 24
Cell organelles: Organelles are small structure with in cells that perform dedicated functions<div>Nucleus :</div><div> Presence : A prominent nucleus is present in eukaryotic cells</div><div>Location :</div><div>In animals cells : In animal cells it is present in the centre</div><div>In plant cell : In mature plants cells , due to the formation of large central vacuole it is pushed to side</div><div>Structure of Nucleus :</div><div>Nuclear envelope : Nuclear is bounded by double small membrane which is called nuclear envelope . Nuclear envelope contains of many small pores that enables it to act as a semi-permeable membrane</div><div>Nucleoplasm : Inside the nuclear envelope a granular fluid is present which is called nucleoplasm . Nucleoplasm contains one or two nucleoli (Singular nucleolus) and chromosomes</div><div><br></div><div>Nucleolus : Nucleolus is a dark spot and is the where ribosomal RNA is formed and assembled as ribosomes</div><div><br></div><div>Chromosome : They are visible during cell divisions while during interphase (non-dividing phase) of the cells . It is present in the form of thread like structure called chromatin chromosomes are made up of deoxyribonucleic acid (DNA) and proteins</div>
Question: 25
Compare prokaryotes cell and eukaryotic cell<div>Similarities :</div><div><br></div>
Answer: 25
There are few similarities between prokaryotic and eukaryotic cells<div>1: They both have DNA as their genetic prokaryotic and eukaryotic cells</div><div>2: They are both membrane bounded</div><div>3: They both have ribosomes</div><div>4: They have similar basic metabolism</div><div>5: They are both amazingly diverse in form</div>
Question: 26
Differentiate between an animal cell and plant cell<div><br></div>
Answer: 26
Animal cell:<div>1: A cell membrane is the outer most boundary of an animal cell . Cell wall is absent</div><div> Centrioles</div><div>2: Centrioles are present in animal cells</div><div> Vacuoles</div><div>3: An animal cell may contain numerous sized vacuoles</div><div> Position of nucleus</div><div>4: The position of nucleus is usually central</div><div> Plastids</div><div>5: There are no plastids in animal cell and hence they cannot manufacture their own food material</div><div><br></div>
Question: 27
Explain relation between cell structure and cell function<div><br></div>
Answer: 27
Cell structure is always in accordance with their function . Cell differ of one type to the other type of cells in the following way<div>Size and shape :</div><div>1: Red blood cells are round to accommodate globular haemoglobin</div><div>2: Nerve cells are long for the transmission of nerve impulses</div><div>3: Xylem cells are tube-like and have thick walls for conduction of water and support</div><div><br></div>
Question: 28
Describe the cell unit of life in term of its structure and function<div><br></div>
Answer: 28
Cell unit of life :<div>Various cells have various structures but when they perform function in coordination with each other then they become unit of life . It means there is a division of labor among the cells of an organism . The phenomenon is common to both animal and plant cells</div><div><br></div><div>Animal cells :</div><div>Different cells are specialized for different functions in animal e.g</div><div>1: Nerve cells conduct nerve impulse and thus contribute in coordination in body</div><div>2: Muscle cells undergo contraction and share their role in movement in body</div><div>3: Red blood cells carry oxygen and white blood cells kill foreign agents and so contribute in the roles of blood in transportation and defense</div><div>4:Some skin cells act as physical barriers against foreign materials and some as receptors for temperature , touch , pain etc</div><div>5: The cells of bone deposit calcium in their extracellular spaces to make the bone tough and thus contributes to the supporting role of bones</div>
Question: 29
How cell work as an open system ?
Answer: 29
A cell works an open system i-e it takes in substance needed for its metabolic activities through its cell membrane . Then it perform the metabolic processes assigned to it .Products and by-products are formed in metabolism . Cell either utilizes the products or transports them to other cells . The by-products are either stored or are excreted out of cell
Question: 30
Explain different phenomenon of transport across a semi permeable membrane
Answer: 30
Diffusion : It is the movement of molecules from an area of higher concentration to the area of lower concentration i-e along concentration gradient<div><br></div><div>Explanation: The molecule of any substance (solid, liquid or gas ) are in motion when that substances is above 0 degrees Kelvin or -273 degrees centigrade . In a substance , majority of the molecules move from higher to lower concentration , although there are some that move from low to high . The overall (or net ) movement is thus from high to low concentrations . Eventually , the molecules from small intestine lumen into the blood capillaries of villi is another example of diffusion</div><div><br></div><div>Passive transport : In diffusion cell does not spend energy when molecules diffuse across its membrane , the diffusion is type of passive transport</div><div>2: Facilitated diffusion : When a transport protein moves a substance from higher to lower concentration , the process is called facilitated diffusion</div><div>Explanation : The rate of facilitated diffusion is higher than simple diffusion . Facilitated diffusion is also a type of passive transport because there is no expenditure of energy in this process</div><div>3: Osmosis : Osmosis is the movement of water across a semi-permeable membrane from a solution of lesser solute concentration to a solution of higher solute concentrations</div><div><br></div><div>Tonicity : It refers to the relative concentrations of solute in the solution being compared</div><div>Types of solution :</div><div>Hypotonic : Solution with relatively lower solute concentrations</div><div>Hypertonic : Solution with relatively higher solute concentrations</div><div>Isotonic :Solution having equal amount or concentrations of solute</div><div><br></div>
Question: 31
What do you know about endocytosis and exocytosis ?<div><br></div>
Answer: 31
Endocytosis :<div>Definition : It is the process of cellular ingestion of bulky materials by the infolding of cell membrane</div><div>Steps of Endocytosis :</div><div>-A portion of cell membrane invigilates</div><div>-The material from outside is taken inside invagination</div><div>-The open ends of invagination seal and form a small vesicle</div><div>-The vesicle detach from the cell membrane and moves into cytoplasm</div><div>Types Of Endocytosis :</div><div>It has two forms</div><div>-Phagocytosis</div><div>-Pinocytosis</div><div>Exocytosis : The process through which bulky material is exported</div><div><br></div>
Question: 32
What are tissues ?Describe different types of animal tissues .
Answer: 32
Tissues :<div>Tissues as a group of similar cells specialized for the performance of a common function .</div><div>In a colony of cells there are many cells and each cell performs all general functions on its own . Such a group does not get tissue level of organization because cells are not specific and there is no coordination among them</div><div>Types of tissues :</div><div>There are two types of tissues</div><div>1: Animal tissues</div><div>2: Plant tissues</div><div>1: Animal tissues</div><div>These are of four major categories</div><div>1: Epithelial tissues 2: Connective tissues</div><div><br></div><div>1: Epithelial tissues: Epithelial tissues covers the outside body and lines organs and cavities . The cells are closely packed together in this tissues . The tissues has many types on the basis of shape of the cells and number of cell layer</div><div>Types :</div><div>It is divided into following types :</div><div>1: Squamous Epithelium :</div><div>It consists of single layer of flat cells</div><div>Location : It is present in lungs , heart , and blood vessels</div><div>Function : It allows material to pass across it</div><div>2: Cuboidal epithelium :</div><div>It consists of single layer of cube shaped cells</div><div>Location : It is present in kidney tubes and small glands</div><div>Function : They make secretions</div><div>3: Columnar epithelium :</div><div>It consists of elongated cells</div><div>Location : It is present in alimentary canal and gall bladder</div><div>Function : They make secretions</div><div>4: Cilliated Columnar epithelium :</div><div>It consists of elongated cells with cilia</div><div>Location : It is present in bronchi and trachea</div><div>Function : The propels in trachea and bronchi</div><div>5: Stratified squamous epithelium :</div><div>They have many layers of flat cells</div><div>Location : It is present in the lining of oesophagus and mouth and also over the skin</div><div>Function : It protects the inner parts</div><div><br></div>
Question: 33
Explain different types of plant issues
Answer: 33
Plant tissues : As in animals , the cells of plants are grouped into tissues with characteristic functions such as photosynthesis , transport etc<div><br></div><div>Types :</div><div>Plant tissues are of two major categories</div><div>1: Simple tissues 2: Compound tissues</div><div> Simple tissues : Tissues which are made up of single type of cell are called simple tissues</div><div>Types :</div><div>It is of two types</div><div>1: Meristematic tissues </div><div>2: Permanent tissues</div><div> -Meristematic tissues : These tissues are composed of cells ., which have the ability to divide . The cells are thin walled have large nucleus and small or no vacuoles . They do not have inter-cellular spaces among them</div><div>Types :</div><div>The main types of meristematic tissues are recognized in plants</div><div>1: Apical meristem 2: Lateral meristem </div><div>Apical meristem: : Apical meristem are located at the apices (tips) of roots and shoot . When they divide they cause increase in the length of plant . Such growth is called primary growth</div><div>Lateral meristem: lateral meristem are located on the lateral sides of roots and shoot . By dividing they are responsible for increase in growth of plant parts . This growth is called secondary growth</div><div><br></div><div>Types :</div><div>They are of two types</div><div>Vascular cambium</div><div>present between xylem and phloem</div><div>Cork cambium</div><div>Present in the outer lateral sides of plants</div><div><br></div>