Parasitism is a type of relationship between two living organisms where one benefits and the other is harmed.
In biology, it is studied as part of ecological interactions.
🧬 Definition
Parasitism is a relationship in which a parasite lives in or on another organism (the host) and gains food or shelter at the host’s expense.
🪱 Key idea
- 🐛 Parasite → benefits
- 🧍 Host → harmed
🧫 Examples of parasitism
🦟 1. Mosquitoes on humans
- Female mosquitoes feed on blood
- They benefit by getting nutrients
- Humans may get diseases like malaria or dengue
🪱 2. Tapeworm in intestines
- Lives inside the human gut
- Absorbs nutrients from food
- Can cause weakness and malnutrition
🪳 3. Lice on humans
- Live on scalp and feed on blood
- Cause itching and irritation
🌿 4. Mistletoe on trees
- Plant parasite
- Takes water and nutrients from the host tree
🦠 5. Bacteria and viruses
Some pathogens behave as parasites:
- Infect host cells
- Use them to reproduce
- Cause diseases like flu or infections
⚖️ Types of parasites
🟢 Ectoparasites
Live on the outside of the host
Examples: lice, ticks, fleas
🔴 Endoparasites
Live inside the host
Examples: tapeworms, malaria parasite
🧠 Why it matters
Parasitism is important because it:
- Affects human health
- Impacts agriculture and livestock
- Shapes ecosystems
🧾 Bottom line
Parasitism is a biological relationship where one organism benefits while the other is harmed, and it is common in both nature and human health contexts.
