P1 Biology p4 (organisation of cells/cancer)

What is the order of organisation in a multicellular organism?

Cell → Tissue → Organ → Organ system → Whole organism

What is a tissue?

Group of similar cells working together to carry out one function

What is an organ?

Group of different tissues working together for a main job

What is an organ system?

Group of different organs working together to do a big body‑wide task

 What causes cancer?

Changes (mutations) in genes that control cell growth and division; cells divide uncontrollably

What is a tumour?

A mass of abnormally‑growing cells

Difference between benign and malignant tumours?

Benign – stays in one place, not cancerous; Malignant – invades other tissues, cells spread (metastasis), cancerous

What is metastasis?

When malignant cancer cells break off, travel in blood, and form new tumours elsewhere in the body

Can inherited genes alone cause cancer?

No — they increase risk, but usually other factors also contribute