• It protects and supports the body.
• The cells are loosely spaced and embedded in an intercellular matrix.
• The matrix may be jelly like, fluid, dense or rigid.
• The nature of matrix differs in concordance with the function of the particular connective tissue.

 

A group of cells that are similar in structure and work together to achieve a particular function is called a tissue

To Express the velocity in m/see need to multiply 1000 to 1.5 and 1 hr=3600 sec.then divide both . 1500/3600 =0.41 To find time taken we can use the formulae . Velocity =total displacement/total time. Total displacement =820 m V=0.41 m/s Total time =displacement/velocity. Time =820/0.41 Time =2000 sec.

What is cell

When distance between objects is halved, force of attraction will become four times.

What is introduction technology

what is that

 LOG IN SUBSCRIBE THE SCIENCES 25 Greatest Science Books of All Time Discover staff present the essential reading list for anyone interested in science. By the editors of DISCOVER magazineDecember 8, 2006 11:30 AM  (Credit: stevemart/Shutterstock) Newsletter Sign up for our email newsletter for the latest science news Sign up for the NewsletterSIGN UP 1. and 2. The Voyage of the Beagle (1845) and The Origin of Species (1859) by Charles Darwin [tie] One of the most delightful, witty, and beautifully written of all natural histories, The Voyage of the Beagle recounts the young Darwin's 1831 to 1836 trip to South America, the Galápagos Islands, Australia, and back again to England, a journey that transformed his understanding of biology and fed the development of his ideas about evolution. Fossils spring to life on the page as Darwin describes his adventures, which include encounters with "savages" in Tierra del Fuego, an accidental meal of a rare bird in Patagonia (which was then named in Darwin's honor), and wobbly attempts to ride Galápagos tortoises. Yet Darwin's masterwork is, undeniably, The Origin of Species, in which he introduced his theory of evolution by natural selection. Prior to its publication, the prevailing view was that each species had existed in its current form since the moment of divine creation and that humans were a privileged form of life, above and apart from nature. Darwin's theory knocked us from that pedestal. Wary of a religious backlash, he kept his ideas secret for almost two decades while bolstering them with additional observations and experiments. The result is an avalanche of detail — there seems to be no species he did not contemplate — thankfully delivered in accessible, conversational prose. A century and a half later, Darwin's paean to evolution still begs to be heard: "There is grandeur in this view of life," he wrote, that "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved." "The most important science book of all time. Darwin revolutionized our understanding of life, the relationship of humanity to all creatures in the world, and the mythological foundation of all religions." — geneticist Lee M. Silver, Princeton University 3. Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) by Isaac Newton (1687) Dramatic is an unlikely word for a book that devotes half its pages to deconstructions of ellipses, parabolas, and tangents. Yet the cognitive power on display here can trigger chills. Principia marks the dawn of modern physics, beginning with the familiar three laws of motion ("To every action there is always opposed an equal reaction" is the third). Later Newton explains the eccentric paths of comets, notes the similarity between sound waves and ripples on a pond, and makes his famous case that gravity guides the orbit of the moon as surely as it defines the arc of a tossed pebble. The text is dry but accessible to anyone with a high school education — an opportunity to commune with perhaps the top genius in the history of science. "You don't have to be a Newton junkie like me to really find it gripping. I mean how amazing is it that this guy was able to figure out that the same force that lets a bird poop on your head governs the motions of planets in the heavens? That is towering genius, no?" — psychiatrist Richard A. Friedman, Cornell University 4. Dialogue Concerning the Two Chief World Systems by Galileo Galilei (1632) Pope Urban VIII sanctioned Galileo to write a neutral treatise on Copernicus's new, sun-centered view of the solar system. Galileo responded with this cheeky conversation between three characters: a supporter of Copernicus, an educated layman, and an old-fashioned follower of Aristotle. This last one — a dull thinker named Simplicio — represented the church position, and Galileo was soon standing before the Inquisition. Galileo comes across as a masterful raconteur; his discussions of recent astronomical findings in particular evoke an electrifying sense of discovery. The last section, in which he erroneously argues that ocean tides prove Earth is in motion, is fascinatingly shoddy by comparison. Galileo, trying to deliver a fatal blow to the church's Aristotelian thinking, got tripped up by his own faith in an idea he was sure was true but couldn't prove. "It's not only one of the most influential books in the history of the world but a wonderful read. Clear, entertaining, moving, and often hilarious, it showed early on how science writing needn't be stuffy." — cognitive scientist Steven Pinker, Harvard University 5. De Revolutionibus Orbium Coelestium (On the Revolutions of Heavenly Spheres) by Nicolaus Copernicus (1543) Copernicus waited until he was on his deathbed to publish this volume, then prefaced it with a ring-kissing letter to Pope Paul III explaining why the work wasn't really heresy. No furor actually ensued until long after Copernicus's death, when Galileo's run-in with the church landed De Revolutionibus on the Inquisition's index of forbidden books (see #4, above). Copernicus, by arguing that Earth and the other planets move around the sun (rather than everything revolving around Earth), sparked a revolution in which scientific thought first dared to depart from religious dogma. While no longer forbidden, De Revolutionibus is hardly user-friendly. The book's title page gives fair warning: "Let no one untrained in geometry enter here." 6. Physica (Physics) by Aristotle (circa 330 B.C.) By contrast, Aristotle placed Earth firmly at the center of the cosmos, and viewed the universe as a neat set of nested spheres. He also mistakenly concluded that things move differently on Earth and in the heavens. Nevertheless, Physica, Aristotle's treatise on the nature of motion, change, and time, stands out because in it he presented a systematic way of studying the natural world — one that held sway for two millennia and led to modern scientific method. "Aristotle opened the door to the empirical sciences, in contrast to Platonism's love of pure reason. You cannot overestimate his influence on the West and the world." —bioethicist Arthur Caplan, University of Pennsylvania 7. De Humani Corporis Fabrica (On the Fabric of the Human Body) by Andreas Vesalius (1543) In 1543, the same year that Copernicus's De Revolutionibus appeared, anatomist Andreas Vesalius published the world's first comprehensive illustrated anatomy textbook. For centuries, anatomists had dissected the human body according to instructions spelled out by ancient Greek texts. Vesalius dispensed with that dusty methodology and conducted his own dissections, reporting findings that departed from the ancients' on numerous points of anatomy. The hundreds of illustrations, many rendered in meticulous detail by students of Titian's studio, are ravishing. 8. Relativity: The Special and General Theory by Albert Einstein (1916) Albert Einstein's theories overturned long-held notions about bodies in motion. Time and space, he showed, are not absolutes. A moving yardstick shrinks in flight; a clock mounted on that yardstick runs slow. Relativity, written for those not acquainted with the underlying math, reveals Einstein as a skillful popularizer of his ideas. To explain the special theory of relativity, Einstein invites us on board a train filled with rulers and clocks; for the more complex general theory, we career in a cosmic elevator through empty space. As Einstein warns in his preface, however, the book does demand "a fair amount of patience and force of will on the part of the reader." 9. The Selfish Gene by Richard Dawkins (1976) In this enduring popularization of evolutionary biology, Dawkins argues that our genes do not exist to perpetuate us; instead, we are useful machines that serve to perpetuate them. This unexpected shift in perspective, a "gene's-eye view of nature," is an enjoyable ­­brainteaser for the uninitiated. So is a related notion: that altruistic behavior in animals does not evolve for "the good of the species" but is really selfishness in disguise. "Like successful Chicago gangsters," Dawkins writes, "our genes have survived, in some cases for millions of years, in a highly competitive world." 10. One Two Three ... Infinity by George Gamow (1947) Illustrating these tales with his own charming sketches, renowned Russian-born physicist Gamow covers the gamut of science from the Big Bang to the curvature of space and the amount of mysterious genetic material in our bodies (DNA had not yet been described). No one can read this book and conclude that science is dull. Who but a physicist would analyze the atomic constituents of genetic material and calculate how much all that material, if extracted from every cell in your body, would weigh? (The answer is less than two ounces.) "Influenced my decision to become a physicist and is part of the reason I write books for the public today." — theoretical physicist Lawrence M. Krauss, Case Western Reserve University 11. The Double Helix by James D. Watson (1968) James Watson's frank, and often frankly rude, account of his role in discovering the structure of DNA infuriated nearly everyone whose name appeared in it, but it nonetheless ranks as a first-rate piece of science writing. The Double Helix takes us inside a pell-mell race whose winners were almost guaranteed fame and a Nobel Prize. Most poignant are Watson's disparaging descriptions of his encounters with DNA researcher Rosalind Franklin. Her X-ray crystallography images showed the molecule to be a helix, crucial data that Watson and his collaborator Francis Crick "borrowed" to construct their DNA model. Franklin died of ovarian cancer in 1958, losing out on the 1962 Nobel Prize for the discovery. Perhaps to atone, Watson noted her key contribution in the epilogue to his book. "The telenovela of my generation of geneticists." — geneticist Mary-Claire King, University of Washington 12. What Is Life? by Erwin Schrödinger (1944) Long a classic among biologists, this volume describes, from the perspective of a Nobel Prize-winning physicist, how living organisms differ from inanimate objects like crystals. Schrödinger carefully outlines how the two groups obey different laws and puzzles over what the "paragon of orderliness" of living things may signify. Some editions include an autobiographical sketch, in which Schrödinger describes the conflict over teaching Darwin that raged when he was in school, as well as his own fascination with evolution. "What Is Life? is what got Francis Crick and the other pioneers of molecular biology in the 1950s interested in the problem in the first place." — cognitive scientist Steven Pinker, Harvard University 13. The Cosmic Connection by Carl Sagan (1973) At a time when NASA was reeling from the end of the Apollo program, Sagan reacquainted both the public and his colleagues with the majesty of the universe, starting with the oft-overlooked worlds of our own solar system. He also championed the search for extraterrestrial life and argued for the likelihood of planets around other stars two decades before they were discovered. The TV series Cosmos brought Sagan to the masses, but the adventure began here. 14. The Insect Societies by Edward O. Wilson (1971) The patriarch of modern evolutionary biology explores the lives of everyone's favorite creepy crawlies — ants, termites, bees, and wasps — in this 500-page treatise unmatched in scope and detail by any other work on the topic (with the possible exception of his own 1990 volume, The Ants). It also lays the groundwork for his 1975 classic, Sociobiology: The New Synthesis, which explores the then-controversial idea that the social behavior of animals, including humans, has a deep biological basis. The book is a labor of love, infused with the author's boundless fascination for his tiny subjects. Wilson openly acknowledges the quirkiness of his obsession; the dedication reads, "For my wife Irene, who understands." 15. The First Three Minutes by Steven Weinberg (1977) When Weinberg was a student, "the study of the early universe was widely regarded as not the sort of thing to which a respectable scientist would devote his time." But after World War II, radar researchers turned their instruments to the sky and helped bring creation stories out of the realm of myth and into the realm of science. Weinberg, winner of the 1979 Nobel Prize in Physics, offered the first authoritative, popular account of the resulting Big Bang scenario in The First Three Minutes. A 1993 afterword discusses more recent advances. Amazingly, only the description of the first fraction of a second of cosmic history has changed significantly. 16. Silent Spring by Rachel Carson (1962) When Silent Spring was first published, a chorus of critics called Carson "hysterical" and "extremist." Yet the marine biologist's meticulously documented indictment of DDT led both to a U.S. ban on the insecticide and to the birth of the modern environmental movement. Carson argues that DDT not only indiscriminately kills insects, including beneficial species like bees, but also accumulates in the fat of birds and mammals high on the food chain, thinning eggshells and causing reproductive problems. Her chilling vision of a birdless America is still haunting. "Over increasingly large areas of the United States," she writes, "spring now comes unheralded by the return of the birds, and the early mornings are strangely silent where once they were filled with the beauty of birdsong." 17. The Mismeasure of Man by Stephen Jay Gould (1981) In this witty critique of bad science, Harvard scholar Stephen Jay Gould sets out to eviscerate the notion of biological determinism. For hundreds of years, Gould argues, questionable measurements of human intelligence, like skull size or IQ, have been used to justify racism, sexism, and class stratification. According to Gould, even respected sociologists and psychologists have used falsified or shaky data to support the belief that Westerners are genetically predisposed to rule the world. The book drew political and scientific criticism, especially from social scientists furious that Gould had oversimplified or demonized their work. 18. The Man Who Mistook His Wife for a Hat and Other Clinical Tales by Oliver Sacks (1985) In these profiles of patients with unusual neurological disorders, Sacks revolutionizes the centuries-old literary tradition of presenting clinical case studies. Far from dryly reporting each case, the eminent British-born New York City neurologist writes in lively prose with the gentle affection of a country doctor on house call and a contagious sense of wonder. To him, the man with Tourette's syndrome and the woman who cannot sense her own body position are the heroes of the stories. Legions of neuroscientists now probing the mysteries of the human brain cite this book as their greatest inspiration. 19. The Journals of Lewis and Clark by Meriwether Lewis and William Clark (1814) One of history's most famous tales of exploration began on May 14, 1804, when William Clark and his Corps of Discovery set off from the mouth of the Missouri River, beginning an epic 28-month journey west to the shores of the Pacific Ocean. (Meriwether Lewis joined the group two days later.) The Journals, a meticulous chronicle of their expedition, offer an unprecedented glimpse at unexplored, undeveloped America west of the Mississippi. Lewis, the group's naturalist and astronomer, and Clark, the surveyor, documented new species of wildlife (coyotes, jackrabbits, mule deer, and others), unfamiliar geology, and interactions with native peoples. A complete copy of the Journals and their companion material is heavy reading (the definitive Nebraska edition has 13 volumes), but an abridged version captures all the adventure in a palatably sized package. 20. The Feynman Lectures on Physics by Richard P. Feynman, Robert B. Leighton, and Matthew Sands (1963) Not only did physicist Richard Feynman win the 1965 Nobel Prize for his work on quantum electrodynamics, he once played bongos for a San Francisco ballet. The beloved book Surely You're Joking, Mr. Feynman! recounts his raucous adventures, but these undergraduate physics lectures, presented over two years at Caltech in the 1960s, are Feynman's true gift to students at all levels. The first 94 lectures cover a wide swath of basic physics, from Newtonian mechanics to electromagnetism, while the final 21 venture into quantum mechanics. Feynman's characteristic humor and peerless explanations elevate these classroom lessons to enduring classics. "Feynman, the prankster-genius, appeals no matter what field you're in. It helps to know some basic physics to approach his lectures, but he has such a luminous mind and is so good with metaphor that you can grasp a fair amount about what's going on in modern physics without formal understanding of complex math, up to a point." — psychiatrist Richard A. Friedman, Cornell University 21. Sexual Behavior in the Human Male by Alfred C. Kinsey et al. (1948) The first of two books known collectively as the Kinsey Report, this treatise became an improbable best seller. With raw, technical descriptions of sexual acts, distilled from thousands of interviews, it documented for the first time what people really do behind closed doors. Many researchers consider the book flawed because of its sampling bias: Most of the men interviewed were young, white, and eager to participate. Nevertheless, the work remains an outstanding model of scientific bravery in the 20th century, with its insistence that sexual acts be described as healthy functions of the human body and that cultural taboos not stand in the way of science. 22. Gorillas in the Mist by Dian Fossey (1983) In a richly hued portrait of the lives and behavior of African mountain gorillas, Fossey documents her 13 years dwelling in a remote rain forest amid these enigmatic animals. One of a trio of protégés picked by famed anthropologist Louis Leakey to conduct field studies of great apes, Fossey was determined, devoted, and often angry — over the apes' diminishing habitat and especially over the danger they faced from poachers (who may have been responsible for Fossey's 1985 murder). In Gorillas she leaves behind a scientific treasure, one rendered more poignant by her death in the service of these peaceful, intelligent beasts. 23. Under a Lucky Star by Roy Chapman Andrews (1943) Roy Chapman Andrews made scientific history during the 1920s by leading five motorized expeditions into unexplored reaches of the Gobi desert. He emerged with the equivalent of paleontological gold: more than 350 new species (including the dinosaurs Protoceratops and Velociraptor), the first fossils of Cretaceous mammals, and the first nests of dinosaur eggs. He packed out plenty of wild tales, too, which are woven into this engaging autobiography. Rumors persist that the fedora-wearing, snake-hating, death-defying explorer may have served as the inspiration for Hollywood's Indiana Jones. 24. Micrographia by Robert Hooke (1665) A revelation in its time, Micrographia exposed the previously hidden microscopic world. Hooke, an early developer of the compound microscope, used his device to peer at the eyes of flies, the stinger on a bee, hairs, bristles, sand particles, seeds, and more, noting every detail with both words and masterful illustrations. The original book is a hefty three pounds, so the digital versions now available are more convenient, but there is something to be said for flipping through a printed copy and discovering, like a hidden treasure, each drawing in its beautiful intricacy. 25. Gaia by James Lovelock (1979) As an inventor of scientific instruments, James Lovelock may seem an unlikely figure to have launched a New Age, earth-mother environmental movement. Yet that's exactly what he accomplished with Gaia: A New Look at Life on Earth. In it Lovelock laid out his daring idea that our planet is a single, self-regulating system, dubbed Gaia, wherein "the entire range of living matter on Earth, from whales to viruses, and from oaks to algae, could be regarded as constituting a single living entity, capable of manipulating the Earth's atmosphere to suit its overall needs." Lovelock has since refined the hypothesis, which many scientists criticized as quasi mystical, and notes that he never implied that Gaia was a sentient being. biologyevolutionphysicspollution MORE FROM DISCOVER  PLANET EARTHCongrats, Jellyfish, the Seas Are Yours! (Now, What Are You Going to Do with Them?)  PLANET EARTHHow Strong Were Ancient Humans? Modern-Day Athletes Are a Window to the Past  HEALTHWhat Would Happen If We Didn’t Have Vaccines?  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given that ,     1st 30 km uniform speed is (u1) = 40 km/h       2nd 30 km uniform speed is ( u2 ) = 20 km/h      total distance ( d ) = 30 + 30 = 60 km      time taken in 1st time = d / t = 30/40 also, 3h / 4 = 180/4 = 45 min      tim taken in 2nd time = d/t = 30/20 also, 3h/2 = 180/2 = 90 min     total time = 45 + 90 = 135 min = 135/60 h av.speed = 60/135/60 = 60 * 60 /135 = 26.66 km/h

Given that ,
    1st 30 km uniform speed is (u1) = 40 km/h 
     2nd 30 km uniform speed is ( u2 ) = 20 km/h
     total distance ( d ) = 30 + 30 = 60 km
     time taken in 1st time = d / t = 30/40 also, 3h / 4 = 180/4 = 45 min
     tim taken in 2nd time = d/t = 30/20 also, 3h/2 = 180/2 = 90 min
    total time = 45 + 90 = 135 min = 135/60 h
av.speed = 60/135/60 = 60 * 60 /135 = 26.66 km/h ( answer )  

Displacement=9 m Velocity= 1.5 km/ hr  =  = (1000/3600)m/s =5/18 m/s To convert km/hr to m/s , just multiply the given value of km/hr by 5/18 1.5 km/hr = 1.5×5/18 = 0.4166 m/s velocity=displacement/Time Time=Displacement/velocity        =9/0.4166        =21.603 sec

Its a humble request to ask questions in english ?

Amoeba is a unicellular organism where single cell performs all the processes like nutrition, respiration, excretion, reproduction etc. The process of procuring food is called as nutrition. Amoeba extends its pseudopodia when the food is found. Pseudopodium just wraps around the food molecule and forms a food vacuole around it. Inside the food molecule, lots of digestive enzymes are secreted to break and digest the food molecule into smaller absorbable substances. Its body helps in its gaseous exchange. Reproduction is by binary fission. It causes a disease called as amoebiasis. This disease affects the intestinal system of the patient.

If u want this in 5 marks ask in the question box, i will type and tell the answer ?

Hi bhavana.. Balanced chemical equation is an equation that have equal numbers of each type of atom on both sides of the arrow. This was the definition of balanced chemical equation. Hope this answer will be useful for your study purpose ?.

• Male Reproductive System:

The human male reproductive system consists of:

1. Testes - Are the primary reproductive organs in males which are in pair. These are oval shaped organs which lie outside the abdominal cavity. It makes the male *** cells called sperms and produces male *** hormones called testosterone. The testes are situated in the scrotal sac outside the main body cavity because the formation of sperms requires a lower temperature than the normal body temperature.
2. ******* - Is a muscular pouch which houses the testes. It is present outside the abdominal cavity and maintains a lower temperature than the normal body temperature.
3. Epididymis - The sperms formed in the testes goes into a coiled tube called epididymis which stores the sperms temporarily.
4. Vas Deferens (sperm duct) - It is a long tube which carries the sperms from epididymis to another tube called urethra.
5. Seminal vesicles and prostrate gland - Both these glands are present along the path of vas deferens and add their secretions to sperms which allows them to transport easily.
6. ***** - It is an organ which passés the sperms from the man's body into the ****** in the women's body during mating.

The secretions of seminal vesicles and prostrate gland provide nutrition to the sperms and also make their transportation easier by secreting a thick liquid.

 

• Female Reproductive System:

The human female reproductive system consists of:

(i) Ovaries - These are the primary reproductive organs in women. They are oval shaped organs which are inside the abdominal cavity of a woman near the kidneys and produces mature female *** cells called ova or eggs. They also produce female *** hormones called Oestrogen and Progesterone. Each ovary is composed of several thousand follicles which mature to form ripe eggs at puberty.

(ii) Oviduct - These are paired tubes which have funnel shaped openings that cover the ovaries. The ovum released by an ovary goes into the oviduct through its funnel shaped opening. The fertilisation of egg by a sperm takes place in it. It is also known as fallopian tube.

(iii) Uterus - It is a bag like organ in which the fertilised egg develops into a baby. It is connected through a narrow opening called cervix to another tube called ******. It is commonly called womb.

(iv) ****** - It is a tubular structure. It receives the ***** for putting sperms into the women's body. It is also called birth canal because it is the passage through which the baby is born.

 

When a girl is born, the ovaries already contain thousands of immature eggs. On reaching puberty, some of these start maturing. One egg is produced every month by one of the ovaries. The egg is carried from the ovary to the womb through a thin oviduct or fallopian tube. The two oviducts unite into an elastic bag-like structure known as the uterus. The uterus opens into the ****** through the cervix. The sperms enter through the vaginal passage during sexual intercourse. They travel upwards and reach the oviduct where they may encounter the egg. The fertilised egg, the zygote, gets implanted in the lining of the uterus, and starts dividing.

The release of an ovum from an ovary is called ovulation. In human females, the ovaries start releasing ovum once every 28 days from the age of puberty. Fertilisation is possible if mating takes place during the middle of menstrual cycle because in a normal healthy girl the ovulation takes place on the 14th day of the beginning of menstrual cycle of 28 days. The embedding of embryo in the thick lining of the uterus is called implantation.

The lining thickens and is richly supplied with blood to nourish the growing embryo. The embryo gets nutrition from the mother’s blood with the help of a special tissue called placenta.

Placenta is a disc like special tissue which develops between the uterus wall and the embryo after implantation. Its function is the exchange of nutrients, oxygen and waste products between the embryo and the mother. It contains villi on the embryo’s side of the tissue. On the mother’s side are blood spaces, which surround the villi. This provides a large surface area for glucose and oxygen to pass from the mother to the embryo. The developing embryo will also generate waste substances which can be removed by transferring them into the mother’s blood through the placenta. The time period from the fertilisation up to the birth of a baby is called gestation. The average gestation period in humans is about 9 months (about 38 weeks).The child is born as a result of rhythmic contractions of the muscles in the uterus.

 

• Equation For Velocity-Time Relation:

Consider the velocity-time graph of an object that moves under uniform acceleration. Initial velocity of the object is u and then it increases to v in time t. The velocity changes at a uniform rate a.

The perpendicular lines BC and BE are drawn from point B on the time and the velocity axes respectively, so that the initial velocity is represented by OA, the final velocity is represented by BC and the time interval t is represented by OC. BD = BC – CD, represents the change in velocity in time interval t.

Let us draw AD parallel to OC. From the graph, we observe that BC = BD + DC = BD + OA

Substituting    BC = v and OA = u,

we get v = BD + u                                                                                                      i.

or BD  = v – u                                                                                                                            ii.

From the velocity-time graph,

The acceleration of the object is given by a = Change in velocity/time taken

= BD/AD = BD/OC

Substituting OC = t, we get

a = BD/t

BD = at                                                                                                                          iii.

Using the equations ii. & iii. We get,

v = u + at

 

• Equation For Position - Time Relation:

Let us consider that the object has travelled a distance s in time t under uniform acceleration a. The distance travelled by the object is obtained by the area enclosed within OABC under the velocity-time graph AB. Thus, the distance s travelled by the object is given by

s = area OABC (which is a trapezium)

= area of the rectangle OADC + area of the triangle ABDM.

= OA × OC + 1/2 (AD × BD)

 

Substituting OA = u, OC = AD = t and BD = at, we get

s = u × t + 1/2 (t×at)

or

s = u t + 1/2 a t²

 

• Equation For Position - Velocity Relation:

From the velocity-time graph, the distance s travelled by the object in time t, moving under uniform acceleration a is given by the area enclosed within the trapezium OABC under the graph. That is,

s = area of the trapezium OABC = (OA + BC) X OC/2

Substituting OA = u, BC = v and OC = t,

We get

s= (u+v) t/2

From the velocity-time relation

We get

t= v - u/a

We have

s = (v + u) x (v – u)/2a

or 2as = v² – u²

 

Take help from YouTube

Lymph	Blood
Definition
It is a colourless fluid.	It is a reddish coloured fluid.
Process occurs in
It is part of the lymphatic system	It is part of the circulatory system
Functions
It helps in body defence and is a part of the immune system.	It is involved in the circulation of nutrients, hormones, oxygen and carbon dioxide, wastes and other toxins.
Comprised of
It contains plasma and a lesser number of WBCs and platelets.	It contains plasma, RBCs, WBCs, and platelets.
Oxygen level
Carries less oxygen and digested food.	Carries more oxygen and digested food.
Proteins and minerals
Lymph plasma lacks proteins.	Blood plasma consists of proteins, calcium, and phosphorus.
Supply of Nutrients
Nutrients are supplied from the cells, tissue to the blood, through lymphatic vessels.	Nutrients are supplied to different organs.

It controls all the metabolic functions of the cell. It helps in transmission of hereditary characters from parents to offspring. It plays a major role in reproduction. It directs many cellular activities of the cell such protein synthesis, cell division,growth etc.

<section itemprop="mainEntity" itemscope="" itemtype="https://schema.org/Question">

The nucleus has 2 primary functions:

• It is responsible for storing the cell’s hereditary material or the DNA.
• It is responsible for coordinating many of the important cellular activities such as protein synthesis, cell division, growth and a host of other important functions.

</section>

Answer:

Functions of Nucleus are:

* It directs and control all the activities .

* It controls all the metabolic activities of the cell and regulates the cell cycle .

* It helps in transmission of heredity characters from parents to offsprings .

* The nuclear membrane has pores which allow the transfer the materials from inside the nucleus to out .

* The nucleus plays a central role in cellular reproduction. It is a process by which a single cell divides and forms two new cells.

Complex tissue: Complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function.
There are two types of complex tissues- Xylem and Phloem.
They are both conducting tissues and constitute a vascular bundle.

Xylem: Xylem is a complex vescular tissue which is in all parts such as root, stem and leaf of the plant. It is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

The cells of this tissue have thick walls and many of them are non-living.

(i) Tracheids: These are long elongated tubular cells. Tracheids cells are dead. They are found in all vascular plants. Its main function is conduction of water and minerals from root to stem.

(ii) Vessels: These are pipe-like structure. Vessels are dead and have lignified cell wall. They also participate conduction of water and minerals.

(iii) Xylem parenchyma: These are simple parenchyma found in the xylem. These are living cells which store food material.

(iv) Xylem fibres: These are dead cells which provide mechanical support to the plant.

Phloem: Phloem is a conducting or vascular tissue of the plants. Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and phloem parenchyma.

and the phloem parenchyma.

(i) Sieve tubes: These are tubular cells with perforated walls. These cells are responsible for transportation of food and nutrients.

(ii) Companion cells: These cells are found associated with sieve tubes and connected with it by simple pits. These cells are long, narrow and thin walled. These cells are living.

(iii) Phloem fibres: They have thick cell wall and they provide mechanical support to plant.

(iv) Pholem parenchyma: These cells are living and often cylindrical in shape.

Signs and symptoms are two different things especially used regarding the disease.
Sign are the representation that can be seen by other , they are not usually seen by the person showing it. And it is the things which is visible externally 

While the symptoms are the internal feeling of the person. It can only described by the person who is having it. For example of you are having the pain , this pain will only feel by you , not any one else.will know until you tell them.

A carrier is an individual who carries and is capable of passing on a genetic mutation associated with a disease and may or may not display disease symptoms. Carriers are associated with diseases inherited as recessive traits. Hosts in which the parasite attains maturity or passes its sexual stage are primary or definitive hosts; those in which the parasite is in a larval or asexual state are secondary or intermediate hosts. A transport host is a carrier in which the organism remains alive but does not undergo development. Agents of diseases are the pathogens which cause the disease.

The number of units in one mole of any substance is called Avogadro’s number or Avogadro’s constant. It is equal to 6.022140857×10²³. The units may be electrons, ions, atoms, or molecules, depending on the character of the reaction and the nature of the substance.

So, if you wanted to know the number of particles in 3 moles of a substance, the value would be:

= 3 x 6.023 x 10²³

= 1.81 x 10²⁴ particles

• Fractional distillation is a process of separating two (or more) miscible liquids by distillation, the distillate being collected in fractions boiling at different temperatures.
• The more volatile liquid (having lower boiling point) distils over first, and the less volatile liquid (having higher boiling point) distils over later.
• A simple fractionating column is a tube packed with glass beads. The beads provide surface for the vapours to cool and condense repeatedly.
• For example: - Mixture of acetone and water can be separated by fractional distillation.

• Fractional distillation is a process of separating two (or more) miscible liquids by distillation, the distillate being collected in fractions boiling at different temperatures.
• The more volatile liquid (having lower boiling point) distils over first, and the less volatile liquid (having higher boiling point) distils over later.

The size of particles of suspension is large enough to be visible from naked eyes. They are greater than 1 nanometre (10−910-9 metre).   General Characteristics of Suspension: Suspensions are heterogeneous mixture of two or more substances. Particles of solute do not dissolve in solvent rather they remain suspended in bulk throughout. The size of particles of suspension is large enough to be visible from naked eyes. They are greater than 1 nanometre (10−910-9 metre). Suspension shows Tyndall effect because of their large size of particles. When suspension is left for some time, particles get settled in bottom. Therefore, suspension is not stable. The particles of suspension can be separated through the process of filtration. Suspension does not scatter light when particles are settled because in this case suspension breaks. Milk of magnesia, fog, mixture of chalk and water, etc. are some examples of suspension.

The size of particles of suspension is large enough to be visible from naked eyes. They are greater than 1 nanometre (10−910-9 metre).

 

General Characteristics of Suspension:

• Suspensions are heterogeneous mixture of two or more substances.
• Particles of solute do not dissolve in solvent rather they remain suspended in bulk throughout.
• The size of particles of suspension is large enough to be visible from naked eyes. They are greater than 1 nanometre (10−910-9 metre).
• Suspension shows Tyndall effect because of their large size of particles.
• When suspension is left for some time, particles get settled in bottom.
• Therefore, suspension is not stable.
• The particles of suspension can be separated through the process of filtration.
• Suspension does not scatter light when particles are settled because in this case suspension breaks.
• Milk of magnesia, fog, mixture of chalk and water, etc. are some examples of suspension.

Those tissues that are made up of structurally different types of cells that are involved in the related functions are called complex tissues. Xylem and phloem are the complex tissues. Xylem is made up of vessels, tracheids, xylem parenchyma, and xylem fibers. Phloem is made up of sieve tubes, companion cells, phloem parenchyma, phloem fibers.

Postulates of Dalton’s Atomic Theory

• All matter is made up of tiny, indivisible particles called atoms.
• All atoms of a specific element are identical in mass, size, and other properties. However, atoms of different element exhibit different properties and vary in mass and size.
• Atoms can neither be created nor destroyed. Furthermore, atoms cannot be divided into smaller particles.
• Atoms of different elements can combine with each other in fixed whole-number ratios in order to form compounds.
• Atoms can be rearranged, combined, or separated in chemical reactions.

True solution

(i) A true solution is a homogeneous mixture of two or more than two substances.

(ii) In a true solution, solute cannot be seen even with a microscope.

(iii) In a true solution, the size of particles is about 10^-10 m.

(iv) The constituents of a true solution cannot be separated by filtration.

Colloid

(i) A colloid is a homogeneous-looking, but heterogeneous-mixture.

(ii) In a colloid, the particles can be seen only with a powerful microscope.

(iii) In a colloid, the size of particle is between 10^-7 – 10^-9 m.

(iv) The constituents of a colloid cannot be separated by filtration.

Suspension

(i) A suspension is a heterogeneous mixture of a solid dispersed in a liquid, or gas.

(ii) In a suspension, the particles can be seen with the naked eyes.

(iii) In a suspension, the size or particle is bigger than 10^-7 m.

(v) The constituents of a suspension can be separated by ordinary filtration.

Colloidal solutions are the type of mixture, where the solute (tiny particles or colloids) is uniformly distributed in the solvent (liquid phase).

(i) A colloid is a homogeneous-looking, but heterogeneous-mixture.

(ii) In a colloid, the particles can be seen only with a powerful microscope.

(iii) In a colloid, the size of particle is between 10^-7 – 10^-9 m.

(iv) The constituents of a colloid cannot be separated by filtration.

.The full form of NAS is National Aerospace Standard. .This was started in the year 1638 and it was well developed in 1960 .This was to help to control the contamination levels of hydraulic fluid within hydraulic components. .These are all the necessary points of NAS. Hope this will be useful for your study purpose ?.

National Aerospace Standard

The National Aerospace Standard (NAS) 1638 was developed in the 1960s to help control the contamination levels of hydraulic fluid within hydraulic components.

Unicellular organisms

• Unicellular organisms are composed of single cell.
• The single cell constitutes the structure and entire function of the organism.
• For example, Amoeba found in marine areas or areas of decaying water is a microorganism composed of single cell that determines the shape of the amoeba.
• Chlamydomonas is another example of unicellular organism found in marine regions.
• Paramecium is also unicellular organism.

Organism which have only one cell For example - ameboa

Organism which are composed of only one cell

Functions
1)They form the outer layer of skin.They protect underlying cells from drying,injury,chemical effects etc.
2)Form lining of mouth and alimentary canal,protect these organs.
3)Help in absorption of water and nutrients.
4)It forms barrier to keep different body system separate.
5)Form lining of blood vessels,alveoli,kidney tubules.
6)They secrete a variety of substances such as sweat saliva,enzymes etc.