Promotion - stages of carcinogenesis, Biology

Assignment Help:

Promotion - Stages of carcinogenesis

The second stage or promotion is reversible and does not include changes in structure of DNA but rather in the expression of the genome of the initiated cell. This results from an interaction among the changed DNA structure and some environmental factors termed 'promoting agents'. The stage of promotion needs extended interaction with the promoting agent, if the third stage of progression is to be teached. Figure describes the process of promotion in a simplified way. A single application of an initiator to the skin of a mouse produces initiated cells but no tumor

1743_Promotion.png

Figure:  The concept of initiation and promotion 

(a) However, if the initiator is applied to the skin first then subsequent application of the promoter results in tumor

(b) If the promoter is withdrawn the tumor regresses leaving behind initiated cells and continued application of promoter on tumor bearing skin lends to invasive carcinoma.

(c) The application of a promoter alone to the skin also does not produce tumor

(d) If the promoter is applied before the initiator is applied even then no tumor is formed.


Related Discussions:- Promotion - stages of carcinogenesis

What is scientific value in biodiversity, Q. What is scientific value in Bi...

Q. What is scientific value in Biodiversity? Nature is a major source of inspiration for scientific thought and the subject of many scientific studies. Biodiversity which const

The chance of fertilisation in humans, Explain why the chance of fertilisat...

Explain why the chance of fertilisation in humans is restricted to only a few days each month. Sperms can fertilise an ovum for up to about three days after entering the female

Define contractile protein - biological functions of protein, Define Contra...

Define Contractile Protein - biological functions of protein? These proteins take part in contractile processes like muscle proteins also those found in other cells and tissues

What is the control center of the cell, What is the control center of the c...

What is the control center of the cell? The nucleus contains DNA, which having the instructions for all the functions of the body.

Lakes - lentic ecosystems, Lakes - Lentic Ecosystems Most lakes occur...

Lakes - Lentic Ecosystems Most lakes occur in regions which have recently been subjected to geological changes; say within the past 20,000 years. However, a few lakes, such a

Which is an isotope of pgisphorous, The most abundant from of phosphorous h...

The most abundant from of phosphorous has 15 protos, 16 neutrons and 15 electrons. Which of the following is an isotope of pgisphorous? (make all correct choices) A. an atom wit

How can nutrients are classified, According to their functions how can nutr...

According to their functions how can nutrients are classified? One possible and utile functional classification for nutrients is the one that divides them into energetic, struc

Why physical fitness is tested, Why Physical Fitness is Tested? 1) To a...

Why Physical Fitness is Tested? 1) To assess pre-training fitness status: Before beginning an exercise programme and allow the exercise, intensity and duration to be set at th

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