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.
Q. What is the etiological agent of visceral leishmaniasis? How the disease transmitted and what is are its typical manifestations? The Visceral leishmaniasis is caused by the
What morphological structure is responsible for bacterial motility?
What are the illustrations of the civil law? Illustrations of the civil law: Illustrations of civil actions are defamation of breach, character of contract, trespassing or
Phases of viruses Viruses have two phases to their existence Inside their host cells where they exhibit certain living characteristics. outside their host where they
Explain about the Alzheimer's Disease? Named after the German neurologist who first described it, Alzheimer's disease is the most common cause of progressive dementia, due to t
Considering a pair of homologous chromosomes containing a gene having two different alleles how many different genotypes can the individual present? If a gene of the diploid sp
What are important terms in accommodation and convergence? Accommodation and Convergence In this section some important terms are included: a. How a person is able to foc
Autonomic Nervous System (ANS) Autonomic Nervous System functions without conscious control of central nervous system. This system controls the functions of cardio-vascular, ga
How can brain research improve the treatment of pain? Despite recent advances in understanding how brain processes and responds to pain, experts say pain continues to be grossl
Explain the Work of John Ray in Animal Taxonomy? The first important work on both animal and plants was initiated by John Ray (1627-1705). He followed Aristotle and divided ani
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