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the food particle forming food vacuole. Inside the food vacuole, complex substances are broken down into simpler ones. Then diffuse into the cytoplasm. The remaining undigested material is moved to the surface of the cell and thrown out. In Paramoecium [fig-9(b)], which is also a unicellular organism the cell has a de... |
in Human Beings Human digestive system is very complex in nature. Different parts are involved and perform different functions by using various digestive juices and enzymes. Let us observe the figure of digestive system and label the parts. The alimentary canal is basically a long tube extending from the mouth to the ... |
me. Now the food material passes from the stomach to the small intestine. Here the ring like muscles called pyloric spincters relax to open the passage into the small intestine. The spincters are responsible for regulating the opening of the passage such that only small quantities of the food material may be passed int... |
ose Trypsin Lipase • Name the enzymes which act on carbohydrates? Free distribution by A.P. Government 15 • Which juice contains no enzymes? • What are the enzymes that act on proteins? Transport of the products of digestion from the intestine into blood (through the wall of intestine) is called absorption. Internally,... |
excessive fat and we get a feeling of nausea. Indigestion is a general term used when there is difficulty in digesting food. Healthy people can usually avoid problems related to digestion by: a) having simple, well balanced meals b) eating them in a leisurely manner c) thoroughly masticating the food d) avoiding takin... |
2. Marasmus: This is due to deficiency of both proteins and calories. Generally this disease occurs when there is an immidiate second pregnancy or repeated child births. Lean and week, swelling limbs, less devoloped muscles, dry skin, diarrhoea, etc., are the symptoms of this disease. 3. Obesity: This is due to over e... |
Sweet potatoes, ground nuts, vegetables, liver, kidney, egg. Burning feat Walking problems, sprain. Biotin Pulses, nuts, vegetables, liver, milk, kidney. Nerves disorders Fatigue, mental depression, muscle pains. Ascorbic acid (C) Green leafy vegetables, citrus fruits, sprouts. Scurvy Delay in healing of wounds, fract... |
Water, photosynthetic pigment chlorophyll. • Chloroplast are the sites of photosynthesis. Light reaction takes place in the grana region and light independent reaction takes place in the storma region. • The end products of photosynthesis are Glucose water and Oxygen. • During photosynthesis the important events which... |
? d) Why is it not possible to demonstrate respiration in green plant kept in sunlight? 3. Give examples (AS1) a) Digestive enzymes c) Vitamins b) Organisms having heterotrophic nutrition d) Food deficiency diseases 4. Where do plants get each of the raw materials required for photosynthesis?(AS1) 5. Explain the necess... |
ll from leaves b) Remove starch from leaves c) Ensure that no photosynthesis occurred d) Ensure that leaves are free from the starch 10. The digestive juice without enzyme is a) Bile b) Gastric juice c) Pancrtatic juice d) saliva 11. In single celled animals the food is taken a) By the entire body surface b) Mouth c) T... |
well). Recall the concepts and answer the following. • Can it be said that Priestley’s experiment helped us to find out more about composition of air? How? Lavoisier also carried out several experiments to understand the property of gases. In his early experiments, it is clear that Lavoisier thought that the gas liber... |
A.P. Government 25 Lavoisier’s findings lead way to several other researchers. • Which gas do you think is Lavoisier talking about when he says chalky acid gas? • Which gas according to him is respirable air? • What steps in the process of respiration does Lavoisier mention as an inference of his experiments? A few li... |
imental set up to test the presence of Carbon dioxide in exhaled air). Arrange apparatus as shown in figure and try to do the experiment once again to find out what happens. lime water water • What does this experiment indicate? • Which gas turns lime water milky? • Which gas do you think might be present in greater qu... |
Bronchioles: Each bronchi is further divided into smaller and smaller Bronchus: Trachea: Larynx: Alveolus: Blood: branches called bronchioles. These finally terminate in clusters of air sacs called alveoli in the lungs which are very small and numerous. Gaseous exchange takes place here as blood capillaries take up ox... |
happens when we swallow food. • Why we are advised not to talk while eating food? Activity-1 Keep your palm around an inch away from your nose, feel you are breathing out, do not remove it until you have finished the activity. Breathe steadily for 1-2 minutes. Now take a piece of any fruit, chew and before swallowing ... |
chest cavity is increased, its internal pressure decreases and the air from the outside rushes into the lungs. This is inspiration (inhalation). Then the reverse occurs. The chest wall is lowered and moves inward, and the diaphragm relaxes and assumes its dome shape. These changes increase the pressure on the lungs; t... |
red, oxygenrich blood is returned to the heart and pumped out to all parts of the body. carbon dioxide oxygen fig-8: Diffussion path way for gaseous exchange between lung and blood capillaries Free distribution by A.P. Government 31 branchiole alveolus blood cells capillary network As a result of gaseous exchange, the... |
the concentration of oxygen is much lower about one fifth at sea level. Under these conditions only about half as increase the pressure on he air out through the nose h of the trachea. the hairs growing from its fig-9: Mountaneer many molecules of oxygen combine with haemoglobin to form oxyhaemoglobin. This is importa... |
. Government 33 outer membrane inner membrane criste matrix fig-10: Mitochondria involves a series of different chemical reactions. From the breakdown of glucose the energy is released and stored up in a special compound, known as ATP (adenosine triphosphate). It is a small parcel of chemical energy. The energy currenc... |
your state of training, and on how hard you ran, you will pant for some minutes after the race, until your breathing gradually returns to normal. fig-11: Athlete (Strenous excercise) These facts could be linked up with what we have learned so far about ATP. It might be that the race was run on the energy produced when... |
muscles, and then only gradually removed from the blood after exercise. What is surprising is that the athlete needs a great length of time to recover. The simplest explanation we can produce at-this stage is that the sugar in the working muscles was being changed to lactic acid. The energy stored in lactic acid molec... |
Arrange apparatus as shown in the figure and heat it over a flame. Does it melt? What happen if you heat for somemore time? glucose test tube heat delivery tube lime water fig-13: CO2 - a by product of energy release When glucose burns, carbon dioxide and water are produced and energy is released as heat. We know that... |
after some rest. Deep breath helps us to restore energy in our body. Refer in annexure about Yoga Asanas. Evolution in gases exchanging system Exchange of gases is a common life process in all living organisms, but it is not same in all. Single celled organisms Amoeba or multicellular organisms like Hydra and Planaria... |
in orchids that produces oxygen is also required by plants to produce energy and carbon dioxide is released. But CO2 is required elsewhrere in the plants try to identify them. Conduction within the plant The stomatal opeinings lead to a series of spaces between the cells inside the plant. Which form a continuous netwo... |
seeds in a cloth pouch and tie with a string tightly. Keep the cloth pouch in a corner of your class room. Next day collect the sprouts/ germinated seeds from the pouch, keep it in a glass bottle/plastic bottle(around 200 ml capacity). Take a small injection bottle, fill three fourth of the bottle sprouted seeds beake... |
2O)n+ O2 CO2+ H2O + Energy 42 X Class Respiration - The energy releasing system Photosynthesis and respiration appear to be opposing reactions, but both have very different biochemical pathways and are essential for a plant’s metabolism. Photosynthesis takes place in the chloroplast to produce sugars, starch and other ... |
A.P. Government 43 sides, remove some of the tiny particles of dirt in the air. In addition, as the inhaled air passes through the nasal cavity, its temperature is brought close to that of the body, and it takes up water vapor so that it becomes more moist than before. • Pharynx is a common passage of digestive and re... |
these carbohydrates are “burned” to produce chemical energy to do work at the cellular level. 44 X Class Respiration - The energy releasing system Improve your learning 1. Distinguish between (AS1) a) inspiration and expiration b) aerobic and anaerobic respiration c) respiration and combustion d) photosynthesis and re... |
) and discuss with your classmates.(AS4) 21. What is the pathway taken by air in the respiratory system? Illustrate with a labelled diagram.(AS5) 22. Draw a block diagram showing events in respiration. Write what you understood about cellular respiration.(AS5) Free distribution by A.P. Government 45 23. How you appreci... |
of air remains in our lungs. So we can make use of 4600ml of lung capacity for breathing. The indian ayurvedic physician. Patanjali developed a scientific breathing practice called Yogabyasa. Maharshi Patanjali proposed a theory called Astanga yoga. He was introduced 195 yogic principles in eight divisions. 1. Yama (S... |
drink liquids, and we breathe gases. Do you think that it is possible to transport all the three types of materials, through a single system? Let us study how this circulation is carried out in our body. Have you ever observed a doctor holding the wrist of the patient and looking at his watch for a minute? What is tha... |
-60 In the year 1816, Rene Laennac discovered the Stethoscope. Before the discovery of stethoscope doctors used to hear heart beat by keeping ear on the chest of the patient. Laennac found that paper tube helps to hear the heart beat perfectly. Then he used a bamboo instead of paper tube to hear heart beat. Laennac cal... |
• Take soda straws and insert them into the stumps of the blood vessels. Note your observations as you proceed. • How many layers are covering the heart? (Now remove the layers covering the heart, and observe) • What is the shape of the heart? • How many large blood vessel stumps are attached to the heart? • Which end... |
parts are called atria (auricles), and the lower ones are called ventricles. The left atrium and ventricle are smaller when compared to that of right atrium and ventricle. The blood vessels found in the walls of the heart are coronary vessels which supply blood to the muscles of the heart. The walls of the ventricles ... |
until 16th century that we really came to know how our blood vessels functioned. In 1574, an Italian doctor, Girolamo Fabrici, was studying the veins in the leg. He noticed that they had small valves in them. If the blood moved in one direction, the valves folded towards the walls of the vessel, so that the blood coul... |
and couldn’t move in the other direction. Harvey now saw what was happening. The heart pushed blood into the arteries, and the blood returned by way of the veins. It did this for both ventricles. The blood had a double circulation. If one started from the right ventricle, it left by way of the arteries to the lungs, a... |
moves in blood vessels? Is it possible to demonstrate the movement of blood in vessels without damaging the vessels? Let us repeat the classical experiment to demonstrate the movement of blood in veins conducted by William Harvey in early 17th century, when there was no compound microscope or any other modern equipmen... |
the clues/options given in the first column. Structure / Function Artery Vein Table-2 1. Thickness of walls(thick / thin) 2. Valves (present / absent) 3. Capacity to retain shape when blood is absent (can retain/collapse) 4. Direction of blood flow (heart to organs / body organs to heart) 5. Pressure in the vessel(low... |
a and pulmonary artery. The aperture between the atria and ventricles is closed by valves. When the valves are closed forcibly, we can listen to the first sharp sound of the heart lub. 5. When the ventricles start relaxing the pressure in the ventricles is reduced. The blood which has entered the arteries tries to come... |
But course taken by the blood is not the same in all the animals. Let us observe the fig11(a) and (b). Start from any point in the fig-11(a) and (b). Move in the direction of arrow. Note down the parts which are in the way in cyclical form. (Try to identify different parts of the body in both figures.) Free distributi... |
to blood. The lymphatic system is a parallel system to venous system which collects tissue fluid from tissues and transports it to the venous system. Blood is a substance which contains solid and liquid particles. Transportation - The circulatory system fig-12: Lymphatic system 60 X Class Lymph is the substance that c... |
om has taken up the function of collection and distribution of materials. Free distribution by A.P. Government 61 The Annelids, the first Eucoelomate animals have developed a pulsatile vessel, to move the fluid and the transporting medium is blood. The Arthropods have developed a pulsatile organ to pump the blood, the ... |
Class Transportation - The circulatory system young adult it will be 120 mm of Hg. The second reading is taken during the resting period, as the ventricles refill with blood. This is called diastolic pressure. It will be 80 mm of Hg. B.P. will change according to the activity in which the person is engaged, such as re... |
essential nutrients and oxygen to perform metabolic activities, and to remove excretory substances which are found in each cell of animal body. Is there anything like that in plants which corresponds to circulatory system? In previous classes we studied about Van Helmont’s experiments on plants, which get water that c... |
root hair by osmosis. Recall the process of osmosis that you have learnt in the chapter “moving of substances through plasma membrane” in class IX. The entry of water dilutes the contents of the root hair vacuole so that it becomes more dilute than it’s neighbouring cell. So, water passes into the neighbouring cell wh... |
evaporates through stomata of leaves and lenticels of stem. When the leaves transpire, there is a pulling effect on the continuous columns of water in the xylem vessels. The top ends of these vessels are surrounded by the leaf’s mesophyll cells which contain cell sap, so the water is continuous from the xylem vessels ... |
g2+ and S04 into the root hairs by the simple process of diffusion, but it involves the use of energy by the cytoplasm which will be discussed in later classes. Once ions are absorbed, the ions travel along with water in the xylem vessels and pass to the growing points of the plants where they are used for growth purpo... |
feel sticky as a result of honey dew. some growth no growth fig-20: Removing ring of bark You may notice that sometimes barks of the tree damaged more than a half, even then the tree is alive. How is this possible? Further experiments to illustrate the conduction of sugars by the phloem have been done by removing a ri... |
thrombin, Thrombin, Fibrinogen, Fibrin, Root hair, Radical, Root pressure, Plant nutrients, Xylem, Phloem, Vascular bundles. What we have learnt • The pulse rate is equal to heart beat. We can count the heart beat without the aid of any instrument. • Rene Lennac discovered the first stethescope. • The heart is covered ... |
largest artery in the body? Why is it big in size?(AS1) 6. Which blood vessel carries blood for oxygenation?(AS1) 7. Name the structures which are present in veins and lymph ducts and absent in arteries.(AS1) 8. What is the use of platelets?(AS1) 9. Write differences betweenm(AS1) a) systole - diastole b) veins - arte... |
stethoscope with paper cup and plastic tube. Write down the procedure of preparation. (AS3) 17. How can you prove that the water is transported through the xylem?(AS3) 18. What is your inference about experiments with aphids?(AS3) 19. Collect information about blood pressure of your school teachers or your nighbours p... |
+). Those who do not have this factor are termed rhesus negative (Rh-). Normally they do not carry an antibody to this factor in their plasma. However, if Rh+ blood is transfused into the blood of a Rh- person, antibodies will be formed and these are capable of destroying Rh+ red cells. Under certain circumstances this... |
carriers of the abnormal Gene for Thalassemia. It is estimated that about 1,00,000 infants are born with major Haemoglobinopathies • every year in the world. 10,000 – 12,000 Thalassemic children are born every year in our country. • • Survival depends upon repeated blood transfusion and costly medicines. • Thalassemia... |
would cause harm to the body, if they are not removed? • What happens if harmful products are not removed from our body every day? We have already learnt that different kinds of materials are produced out of various metabolic activities. Some of these may be harmful for the organism are removed from their body or pack... |
PHORUS BILURUBIN(TOTAL) TOTAL PROTEINS ALBUMIN 82 137 4.10 101 29 2.8. 7.50 221 167 9.40 4.50 0.70 7.20 4.60 mg/dl mmoles/L mmoles/L mmoles/L mg/dl mg/dl mg/dl mg/dl mg/dl mg/dl mg/dl mg/dl g/dl g/dl 60-100 (GOD POD) 135-145 3.5-5.0 95-106 15-40 0.6-1.5 3.0-5.0 150-200 60-200 8.0-10.5 3-4.5 0.1-0.8 6.0-7.5 3.0-5.0 Tabl... |
goat / sheep, which is similar to Human kidney in function. Lab Activity Aim: Studying the external and internal features of a kidney Materials required: Freshly collected specimen of sheep/goat’s kidney from the butcher or 3D Model of a kidney, sharp blade/scalpel, tray and a jug of water. Procedure for observation: ... |
al gland renal artery left kidney renal vein left ureter opening of ureter into bladder bladder urethra external opening fig-4: Excretory system fig-3: Location of kidneys Internal structure of the kidney: Let us observe L.S of the kidney to know more about internal structure. It shows two distinct regions. Dark colour... |
by a network of peritubular (around tube) capillaries formed from efferent arteriole. The peritubular capillaries join to form renal venule, which joins the other venules to form finally the renal vein. • Why the nephron is considered to be the structural and functional unit of the kidney? Free distribution by A.P. Go... |
the area of loop of Henle. Further concentration of urine takes place in the area of collecting tubes in the presence of 80 X Class Excretion The wastage disposing system i) Glomerular filtration: Blood flows inside the glomerulus under the influence of pressure due to the narrowness of efferent arteriole. As a result... |
rethra It is a tube that takes urine from urinary bladder to outside. The opening of urinary bladder into urethra is guarded by a ring of muscles or sphincter. Urethra is 4 cm long in females and about 20cm long in males. Its opening is separate in females but is in common with the reproductive tract in males (urino-ge... |
creatine, creatinine, water soluble vitamins, hormones, and oxalates etc) and 1.5% of inorganic solutes (sodium, chloride, phosphate, sulphate, magnesium, calcium, iodine). It is acidic in the beginning but becomes alkaline on standing due to decomposition of urea to form ammonia. • What happens if both kidneys fail c... |
salts of calcium magnesium and iron are excreted by epithelial cells of colon (large intestine) for elimination along with the faeces. Small amount of nitrogenous wastes are also eliminated through saliva and tears. Excretion in other organisms Different organisms use varied strategies in excretion. Specific excretory... |
its body? Plants can get rid of excess water by a process like transpiration and guttation. Waste products may be stored in leaves, bark, and fruits. When these dead leaves, bark, and ripe fruits fall off from the tree then waste products in them are get rid off. Waste gets stored in the fruits in the form of solid bo... |
machine is an artificial kidney which filters the blood to remove the metabolic wastes out side the body. • Kidney transplantation is a permanent solution to renal failure patients. • Different animals have different excretory organs e.g. amoeba-contractile vacuole, platyhelminthesflame cells, annelida-nephridia, arth... |
proteins in liver is brought into organ P through blood by an artery R. The numerous tiny filters S present in organ P clean the dirty blood goes into circulation through a vein T. The waste substance Q other waste salts and excess water form a yellowish liquid U which goes from organ P into a bag like structure V thr... |
path way of excretory system in human being.(AS5) 20. If you want to explain the process of filtration in kidney what diagram you need to draw.(AS5) 21. List out the things that makes you amazing in excretory system of human being.(AS6) 22. You read about ‘Brain dead’ in this chapter. What discussions would you like t... |
rea (b) sodium (c) water (d) creatine 6. Special excretory organs are absent in (a) birds (b) amoeba (c) sponges (d) a and b 7. Which of the following hormone has direct impact on urination? (a) adrenal (b) vasopressin (c) creatine (d) estrogen 8. Amber colour to urine due to (a) urochrome ( b) bilerubine (c) bileverdi... |
th’s parents are? Annexure Organ donation - A gift for life So many patients are waiting for suitable organ due to failure of vital organs. In Hyderabad where there are kidney transplantation facilities minimum 25 patients per hospital are waiting for kidney donors. Daily 10 - 100 people met with accident in our State.... |
you think needed in coordination and balance? All our functions are carried out by an effort of several systems working together. For example, while movement, we hardly ever use just the skeletal system or muscular system alone, several other systems also have their own roles to play. Even within the muscular system, ... |
erve cell 96 X Class covering also forms a partition between adjacent axons. The nerve cell body lies either in our brain or spinal cord or very close to the spinal cord in a region called dorsal or ventral root ganglion. In the brain or spinal cord, it is difficult to make out the difference between dendrites and axon... |
information carried on the afferent and efferent nerves? Brain or spinal cord Afferent nerves Assossiation nerves Efferent nerves Muscles of the organ fig-7: Different nerve pathways Activity-3 Knee jerk reflex Activity-1 showed a response on which you had some control or it was voluntary (recall the use of the volunt... |
-9, how our leg muscle responds when we step on a sharp edged object. • What other effectors would act under these circumstances? • What does this tell us about the association of nerves? In fact, you must have experienced, what happens when you do things consciously and otherwise. Say for example, when you are perform... |
, the function of the brain as a control center was known nearly 2000 years back by Greek physiologists. Brain has the following divisions – 1. Forebrain – cerebrum, diencephalon 2. Midbrain – optic lobes 3. Hindbrain – cerebellum, medulla. Table-1: Functions of the various parts of the brain Part of the brain Function... |
removed. ‘Leonardo da Vinci’ (1452-1519) and ‘Stephen Hales’ (1677-1771) both recorded the survival frogs those brain had been destroyed. The animal still produced muscular moments if its skin was pinched or pricked. Both observers further recorded that the animal died as soon as spinal cord was damaged by pushing a n... |
blood vessels, smooth and cardiac muscles.So it is called autonomous nervous system. It has voluntary control of muscles of some areas of skin and the skeletal muscle. We can take up an example to see how certain involuntary function controlled by autonmous nervous system takes place in our body. A very evident observ... |
fig-15: Pancreas The next stage was reached when it was found that tying up the pancreatic duct that emerged from the duodenum( a part of the small intestine) would cause the pancreas to degenerate but the Islets of Langerhans would remain normal. Moreover, an animal so treated would not develop diabetes. This was rea... |
afraid, the rate of heart beat increases; the breath rate will be faster; blood pressure increases; the hair on the body becomes erect and we get goose bumps. The other things we might not observe are pupil dilation, skin becomes more sensitive, and rarely the bladder and the rectum may be emptied. We come to normal s... |
- The liking system Free distribution by A.P. Government 107 of the body. This means that there should be some mechanism to regulate the production and release of hormones in the body. The timing and amount of hormones released by endocrine glands is controlled by the feedback mechanism, which is inbuilt in our body. ... |
. Here cells contain lot of water and large intercellular spaces. Due to water pressure pulvini hold the leaf erect. Touch me not plant shows nastic movement by touch. This is called thigmonasty. When we touch the leaves, an electrical impulse is generated. This impulse acts on plant hormone. Because of this hormone wa... |
erve how root and shoot grows. Then tilt the glass jar and keep the plant horizontally. Observe the direction of root and shoot growth for more than a week. • Does the shoot take a horizontal tilt after a week? • Which side of the shoot may have grown more and which side less to bring about this effect? Observe the pla... |
ic and nastic movements in plants The above experiments show that movement of individual parts of plants is possible when they are subjected to external stimuli. This type of response is called tropism or tropic movement. Sometimes the direction of stimuli determines direction of movement, sometimes the direction of mo... |
two systems that control and coordinate various functions in the body. • The responses of the nervous system can be classified as reflex, voluntary and involuntary actions. • The human nervous system is studied under two divisions: The central nervous system and the peripheral nervous system. • The central nervous sys... |
inguish between(AS1) a) Stimulus and Response c) Central nervous system and peripheral nervous system d) Receptor and effector b) Afferent and Efferent nerves 6. How does Phototropism occur in plants?(AS1) 7. Give an example and explain how plants may immediately respond to a stimulus.(AS1) 8. Suggest an experiment to ... |
books from your school library.(AS4) 23. Read the following sentences and compare with endocrine glands.(AS4) Pheromones are chemical substances secreted by organisms. These act as chemical signals secreted by exocrine glands. Pheromones are used as signals by the members of same species. Honey bee secretes pheromones... |
curd in both the bowls. • Does it take the same time to form curd in both the bowls? • What is the time taken to form nearly 30 times the size of the bacterial colony indicate? Think, how fast they are growing. During rainy season you may have wondered how swarms of insects suddenly appear. Most insects have life cycl... |
Ex: Nerium. Grafting: Two plants are joined together in such a way that two stems join and grow as a single plant. One which is attached to soil is called stock and the cut stem of another plant without roots is called scion. Both stock and scion are tied with help of a twine thread and covered by a polythene cover. G... |
angium) bursts, the spores spreads into air. These air-borne spores land on food or soil, under favourable conditions like damp and warm conditions, they germinate and produce new individuals. Most of the fungi like Rhizopus, Mucor etc., Bacteria and non-flowering plants such as ferns and mosses reproduce by the method... |
little of the mould and place it on the drop of water. 3. Take the cover slip and set it at an angle to the slide so that one edge of it touches the water drop, then carefully lower it over the drop so that the cover slip covers the specimen without trapping air bubbles underneath. 4. Use the corner of a tissue paper ... |
, the two testes are located in pocket like structure outside the body wall called the scrotum. The male reproductive cells, the sperms, are produced in very large numbers (hundreds of millions). Observe the fig-13 of male reproductive system and findout parts essential for the transport of the sperm cells. Each testes... |
cavity filled with fluid. Each follicle contains a single ovum which is formed after the process of cell division (meiosis). When an ovum is mature, the follicle ruptures at the surface of the ovary and the tiny ovum is flushed out. This release of the egg or ovum is called ovulation. Generally the ovum enters the wid... |
. Placenta is a tissue formed by the cells from the embryo and the mother. It is formed at around 12 weeks of pregnancy and becomes an important structure for nourishment of the embryo. Under normal conditions there is no direct flow of blood from mother to the young. The blood systems of the two are separated by thin ... |
muscles become stronger and more frequent, and the baby is pushed through the vagina and into the outer world. The umbilical cord leading from the baby to the placenta, is tied off and cut by the doctor. (The small piece of cord remaining attached to the baby shrivels and falls off within a few days. The navel marks t... |
have already studied the different parts of the flower- sepals, petals, stamens and carpels. The reproductive parts of the flower which possess the sex cells or germ cells called stamens and carpels. • What function do you think is served by petals and sepals? • Draw the diagram of the flower that you collect and labe... |
. Do you know what is self-pollination? Let us now observe some smaller parts that are involved in the process of reproduction in plants. The male reproductive part or the stamen consists of some sac like structures at its head bearing small ball like structures. We can easily observe these structures called pollen wit... |
bears to nuclei. Soon after the tip of the pollen tube enters the embryo sac, the end of the tube ruptures and releases the two sperms into the embryo sac. One of the two sperms fuses with the egg to form a zygote. By the time the egg cell has been fertilized, the two polar nuclei combine to form a single fusion nucle... |
may shrivel and fall off. 130 X Class Reproduction - The generating system • Which floral parts is may be seen in a fruit? The seed produced after fertilisation contains the future plant or embryo that develops into a seedling under appropriate conditions. The process is called germination. Activity-3 Seed germination... |
flamming In 1879 Walther Flemming (1843–1905) examined many kinds of animal and plant cells and selected those that showed division. He reported from his observations of such cells that there were string like structures in the nucleus which split longitudinally during cell division. He named such a process of division... |
think, analyse and interpret the data. August Weiseman’s poor eyesight forced him to spend time thinking. Think how great he was! The scheme of mitotic division was confirmed in 1904 by Theodor Boveri (1862–1915). The chemical nature of the genetic material was determined after a series of experiments over the next fi... |
1 (10.5 hrs) fig-28: Interphaace Cell cycle The process of cell division is called ‘Mitosis’, which is completed in 40 to 60 minutes (this is the time of active division). The period between two cell divisions is called ‘Interphase’. This is actually the period when the genetic material makes its copy so that it is equ... |
ids, connected by centromeres. 3. Nuclear membrane breaks down. 4. Centrosome, containing rod-like centrioles, divide and form ends of spindle (probably animal cells only). (Note: No pairing of chromosomes as in meiosis). 2. Metaphase 1. Chromosomes move to spindle equator, centromeres attached to spindle fibres. 2. Ce... |
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