Short coming of cell theory, Biology

Assignment Help:

SHORT COMING OF CELL THEORY / EXCEPTIONS OF CELL THEORY

(i)       Viruses can be considered as exception to cell theory. They are made of proteins and ones of nucleic acid i.e.

DNA or RNA. They are inert except when in a living cell. They are incapable of self regulation, self reproduction and independent existance, so they lack protoplasm, the essential part of the cell.

(ii)      Bacteria & Blue green algae, which are prokaryotes lack well organised nucleus, nuclear membrane, nucleolus and nucleoplasm. Chromatin is in direct contact with cytoplasm.

(iii)     Protozoans are not cellular, they are acellular. i.e. there body is not divisible into cells.

(iv)      Coenocytic hyphae of Rhizopus (fungus) and algae like Vaucheria are multinucleate and aseptate. RBCs lose nuclei and many organelles but still keep living.


Related Discussions:- Short coming of cell theory

What is reaction specificity, Reaction specificity Some  enzymes  catal...

Reaction specificity Some  enzymes  catalyze only one  reaction  acting  on  a specific substrate. Example: urease  and  catalase  acts  only  on  urea and  hydrogen peroxide,

Is herbivorism a form of predatism, Q. Is herbivorism a form of predatism? ...

Q. Is herbivorism a form of predatism? The Herbivorism is a form of predatism in which first order consumers feed from producers (plants or algae). For instance, fruits and bir

Division phase or mitosis, DIVISION PHASE OR MITOSIS (M- PHASE) Cell di...

DIVISION PHASE OR MITOSIS (M- PHASE) Cell division was first  observed by  Naegeli 1842 in plant cells ,but  thoroughly described by Eduard strasburger  1875. Fleming 1879 desc

Autotrophic and heterotrophic succession, Autotrophic and Heterotrophic Suc...

Autotrophic and Heterotrophic Succession The succession where initially the green plants are much greater in quantity than the animals, is known as autotrophic succession. Su

Homologous series, Homologous series A homologous series can be illust...

Homologous series A homologous series can be illustrated as a group of compounds in which the several members have similar structural features and identical chemical propertie

Why cerebellum more developed in mammals that fly or jump, Q. Why is the ce...

Q. Why is the cerebellum more developed in mammals that fly or jump? The cerebellum is the main brain structure that coordinates the movement and the equilibrium of the body. F

What is the significance of proteins for living beings, What is the signifi...

What is the significance of proteins for living beings? Proteins play a fundamental role in nearly all biological processes. Because of their diversity they can assume many dif

What are the hexoses, Q. What are the hexoses? What are some examples of he...

Q. What are the hexoses? What are some examples of hexoses with vital biological functions? Hexoses are carbohydrates whole of six carbons. Galactose, fructose and Glucose are

Wetlands - lentic ecosystems, Wetlands - Lentic Ecosystems Wetlands a...

Wetlands - Lentic Ecosystems Wetlands are permanently or periodically water covered areas. They can be defined as submerged or saturated lands either artificially or naturall

Human respiratory system - larynx, LARYN X - Study of larynx is kno...

LARYN X - Study of larynx is known as Laryngeology. In man it is more prominent than woman known as Adam's apple. It is sound producing organ. At its base trachea presen

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd