In this IBDP Biology blog post, we will be looking at the causes and formations of tumors and how they are related to the cells.
Cancer: Normal control systems that prevent cell overgrowth and invasion of other tissues are disabled.
This forms tumors (the result of uncontrolled cell division), which can occur in any organ or tissue
Benign tumors: Only grows locally and cannot spread by invasion or metastasis
Malignant tumors: cells invade neighboring tissues or enter blood vessels
Causes of tumors
Mutagens: physical or chemical agents that contribute to mutations
o Environmental (tobacco, pollution, chemical radiation, UV light)
o Genetic (genetic predisposition)
Oncogenes: genes that code for the proteins that are responsible for regulating cell division and the cell cycle
o Mutations that occur in oncogenes can lead to cancer
Metastasis: The ability for cancer cells to penetrate into lymphatic and blood vessels, circulating through the blood stream and evading tissue elsewhere
Cells get out of control -> tumour
Primary tumour: tumour occurs at original site of cancer
Secondary tumour: metastasis, a cancerous tumour that has spread from original part of organism to another e.g. brain tumour -> composed of breast cancer cells
Some cases: metastasis of primary tumour cells so extensive that secondary tumours are found in many locations of organism
That is all for this post!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3ANormal_and_cancer_cells_structure.jpg&psig=AOvVaw3ZtTyzTXz6bHN6vLuT-RR1&ust=1627662972420000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCICT8ZzbiPICFQAAAAAdAAAAABAo
https://www.google.com/url?sa=i&url=http%3A%2F%2Fib.bioninja.com.au%2Fstandard-level%2Ftopic-3-genetics%2F34-inheritance%2Fgene-mutation-rates.html&psig=AOvVaw1bg22DrTbrimoIkZDMQW1K&ust=1627663046048000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCJDW37_biPICFQAAAAAdAAAAABAD
Drafted by Venetia (Biology)