Q. 23

How do normal cel

Answer :

Normal cells in the body have an age and a time period to live after which they degenerate or divide and differentiate into newer cells. And during this division and differentiation if the cell has some abnormal changes and loses its contact inhibition then it starts to multiply uncontrollably and in a haphazard manner leading to formation of a tumour which may either be benign or malignant (cancerous).

Cells may also become cancerous after coming in contact with a carcinogen which may be external or internal.


OR


a) High Biological Oxygen Demands of a water body indicates that the water body is highly polluted and it contains high quantity of bacteria.


As the amount of bacteria increases the B.O.D. of water also increases.


b)The B.O.D. of primary effluents during secondary treatment in sewage treatment tanks decreases by 10-15% as the bacterial masses are held together by the use of flocs and the microbes digest a lot of organic matter.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

(a) What wBiology - Exemplar

Why is aerobic deBiology - Exemplar

(a) DiscusBiology - Exemplar

Why are flocs impBiology - Exemplar