Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Cell Theory
The invention of the compound microscope in the 17th century stimulated the interest in living things not visible to the naked eyes. Thus, Robert Hooke discovered 'cells' in 1665 by examining cork slices (,under a crude microscope. He was actually describing the spaces occupied by the cells limited by the cellulose walls. Hooke and his contemporaries also described cells from other plants and animals.
Figure: A generalized plant (a) and animal (b) cell. No one cell of either plant (a) or animal (b) has all the characteristics shorn in these composite figures. Both these are
However, cell theory, one of the greatest and most basic generalizations of biology, was formulated only about 200 years later. Two German investigators, Schleiden a botanist (1838), and Schwann, a zoologist (1839) are credited with presenting independently the first concise, yet comprehensive, statements about the cell. They pointed out that, "All plants and. animals are made up of small fundamental units called cells and that some organisms are unicellular and others, multicellular." Subsequent researched to the expansion of this concept by including further information on cells. We know that cells are surrounded by cell membrane and contain cytoplasm and nucleus and, most importantly, cells divide into roughly equal daughter cells by a process called cell division. Thus it became known that new cells come into existence only by the division of previously existing cells. In other words, cells do not arise by spontaneous generation from nonliving matter. It follows that all cells living today can trace their ancestry back to those which existed in ancient times.
(i) Effect on Human Health: Air pollution causes many respiratory problems in human being. (1) Dust, soot and smog causes several respiratory troubles such as bronc
Q. Write the meaning of Polyuria? Increased Urine (Polyuria): When sugar is increased in the blood it is filtered from the body along with the water. This is the reason for fre
Rehabilitation Phase for nutritional treatment - Neuro Trauma? Once the patient stabilizes and starts recovering, be sides nutritional replacement, there is a need to assess fu
Explain the Direct Surface Agar Plating Method? In the direct surface agar plating method, molten agar is placed on to the surface to be assessed. Upon hardening, it is incubat
Descent of the Testis The testis develops on the posterior abdominal wall at the mesonephric ridge. To reach the adult position in the scrotum, it must decent. A fibrous cor
Determine the principles of Behavioural neuropsychology Behavioural neuropsychology approaches are based on the principles of learning theory and behavioural modification. Beh
A v i a n infectious bronchitis (IB) An acute, highly contagious respiratory disease of chicken caused by a member of the family Coronaviridae, IB was first recognized in I
Explain about the Pasteurization? You must be aware of the various pasteurized products available in the market. The most commonly used product being ‘milk'. Why do we need to
Doppler echocardiojgraphy measures blood flow velocities and direction of blood flow in the heart add great vessels. The characteristics of blood flow are evaluated using both a
Determine which of the following observations (A-J) could lead to a testable hypothesis. For those that are testable: Write a hypothesis and null hypothesis What would be your expe
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd