In human body, the cell growth and differentiation are highly controlled and regulated, but in cancer cells
There is breakdown of these regulatory mechanisms leading to formation of benign and malignant tumours
The correct answer is There is breakdown of these regulatory mechanisms leading to formation of benign and malignant tumours.
Normal cells divide only in response to growth signals and stop by contact inhibition, under the control of proto-oncogenes, tumour-suppressor genes (e.g., p53) and apoptosis. In cancer, mutations break down these controls, so cells divide uncontrollably and form a mass (tumour) that may be benign (localised) or malignant (invasive, metastatic).
Cell division in cancer is uncontrolled, not controlled; mutations alter DNA and RNA rather than reduce their production — rapidly dividing cancer cells actually synthesise more DNA.
Short trick: Cancer = loss of control (no contact inhibition) → tumour.
The causal organism of dengue fever is a mosquito-borne virus which belongs to which one among the following categories?
Which of the following statements is/are correct about vaccination that provides
protection against an infectious disease?
1. It blocks the entry of the infectious agent into body.
2. It produces antibodies against infection.
3. It kills the infectious agent when it enters in the body.
Select the correct answer using the code given below.
Which one of the following hormones contains peptide chain?
Which of the following cells are destroyed by the HIV virus which results in the weakening of the immunity of a person?
Which one of the following hormones is essential for the uptake of glucose by cells in the human body?
Which of the following cells do not contain a nucleus?
1. Root hair cells
2. Red blood cells
3. Platelets
4. Monocytes
Select the correct answer using the code given below.‘Altitude sickness’ is caused at high altitude due to
Fat in human body is stored in
Urea is produced by metabolism of
Which one of the following functions is not carried out by smooth endoplasmic reticulum?
Consider the following statements regarding diabetes:
1. It is caused by the oversecretion of insulin by pancreas.
2. The glucose level increases in the blood.
3. The patient urinates frequently, loses weight and becomes lethargic.
How many of the statements given above are correct?