Objection of cell theory, Biology

Assignment Help:

OBJECTION OF CELL THEORY (REASONS OF DISCARTION)

(i)       Living organism are composed of various types of cells and their product but members of monera & protista don't have a cellular organisation, they have protoplasmic grade & organization.

Cell theory is not applicable on viroids, Viruses, Prions.

(ii)      In multicellular organism one type of cell perform one type of function. It doesn't perform all vital activities.

(iii)         Gene is the hereditary unit of life according to modern view - Physical unit of life = Gene

Chemical unit of life = DNA

(iv)      In plants many dead cells are present, which also have specific function. Vessels and Tracheids of Xylem are dead cells but helps in conduction of water & minerals. In human beings, cells of stratum corneum (outermost layer of skin) are dead & helps in protection.

(v)      It was not discarded but modified by Nageli, he just added "through cell division" while omnis cellula e cellula means that cells arise inside the cell. According to Karl nageli "new syncytes arise from division of pre-existing cells".


Related Discussions:- Objection of cell theory

Active transport during membranes, Q Which are the molecules that make poss...

Q Which are the molecules that make possible active transport during membranes? Active transport is prepared by specific membrane proteins. These proteins are known as "pumps"

Difference between reproduction system of man and rabbit, Difference betwee...

Difference between Reproduction System of man and rabbit -   S.No.   Man   Rabbit   1.   2.   3.

Where in living beings can found mineral salts, Q. Which are mineral salts?...

Q. Which are mineral salts? Where in living beings can found mineral salts? Ans. Mineral salts are simple inorganic substances made of metallic chemical elements, like sodiu

What is a food chain?, What is a food chain? The food chain is not bran...

What is a food chain? The food chain is not branched it is linear sequence in which a living being serves as food for another, starting with the producers and going up to the d

Determine what is the Cell Cycle, The cell cycle undergoes a sequence of ch...

The cell cycle undergoes a sequence of changes which involve a period of growth replication of DNA, Followed by cell division. This sequence of changes is called cell cycle.

Parasites - biological stress, Parasites - Biological Stress Many inse...

Parasites - Biological Stress Many insects and microorganisms can feed upon tissues and saps of living plants. Hence plants must be protected against such parasites either by

Types of insulin, There are different types of insulin available and prescr...

There are different types of insulin available and prescribed by the doctor according to the need of the patient. Insulin is grouped according to the speed of action in the body i.

Human respiratory system - alveoli, A L VEOL I - Sac like structu...

A L VEOL I - Sac like structure, unit of lungs. Increase surface area, exchange of gases occur in it. Rich in blood capillaries. Aloeoli join by pore of Kuhn to form a

Describe consciousness as the waking state, Q. Describe Consciousness as th...

Q. Describe Consciousness as the waking state? Consciousness as the waking state: consciousness is also referred to as the waking state as opposed for example to sleep. All

Water potential, why psi g is ignored in water potential of plants?

why psi g is ignored in water potential of plants?

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