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.
What is the concept of universality of the genetic code? What are the exceptions to this universality? The genetic code is universal because the rules of protein codification b
What is the Determination of vitamin B 2 In the chemical method, the yellow-green fluorescence of aqueous solution of riboflavin is measured. In the microbiological assay, tur
what is respiration in animals ,its functions ,types of respiration
Will there be an opportunity to comment? In a supplemental notice accompanying the last rule package, EPA is soliciting additional information and public comment on issues fro
Q. How do cells of neoplastic tumors obtain oxygen and nutrients and release wastes? In the neoplastic tumors a phenomenon called as angiogenesis occurs. The Angiogenesis is th
In this unit you have learnt that heart failure is one of the most common conditions seen and results in a high mortality. It can result from failure of the heart muscle as with co
Psychology : This is the study of human mind. On other words Psychology is the science of behavior or mental processes. Its immediate aim is to understand the individuals or groups
Q. What is the difference between spermatocyte II and spermatocyte I? The spermatocyte I (2n) undergoes the first division of meiosis (meiosis I) originating two spermatocyte I
Define Some Food Related Problems in parkinson's disease? As the disease progresses some food related difficulties appear. These are: 1. Difficulty in food preparation
Strawberries are quick frozen at a rate of 6500 kg/h. The fruit enters the freezer at a temperature of 15°C and is frozen to a final temperature of -20°C. Calculate the rate of hea
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