*8th CBSE Science – Chapter 2: Microorganisms*
_Exam-Focused Notes_
*1. Definition*
*Hindi:* _Sukshmajeev_ wo chhote jeev hain jo aankh se nahi dikhai dete. Inhe
microscope se dekha jata hai. Ye hawa, pani, mitti aur hamare sharir me har jagah milte
hain.
*English:* Microorganisms are tiny living beings not visible to the naked eye. They are
seen under a microscope. They are found everywhere – in air, water, soil, and inside our
bodies.
*2. Key Points*
- Microorganisms 4 types ke hote hain: *Bacteria, Fungi, Protozoa, Algae* + *Virus*
- Kuch microorganism *useful* hain: Dahi jamana, bread banana, dawai banana, mitti ko
upjau banana
- Kuch *harmful* hain: bimari failana – TB, Cholera, Malaria
- *Lactobacillus* bacteria se dahi jamta hai
- *Yeast* fungi se bread phoolta hai
- *Nitrogen-fixing bacteria* mitti me nitrogen badhate hain
- Virus sirf living cell ke andar hi badh sakta hai. Isliye ise zinda aur murda ke beech
mana jata hai
- Harmful microbes se bachne ke liye khana dhak ke rakho, pani ubal ke piyo, vaccine
lagwao
*3. Diagram Description*
_Bacteria ka structure:_ Chhota, chhadi jaisa ya gol shape. Bahar ek cell wall, andar
cytoplasm aur DNA. Kuch bacteria me baal jaisi structure “flagella” hoti hai jo hilne me
madad karti hai.
*4. Important Q&A for Exam*
*Q1. Microorganisms kise kahte hain?*
Jeev jo aankh se nahi dikhte, microscope se dekhe jate hain.
*Q2. Dahi kaise jamta hai?*
Lactobacillus bacteria doodh me sugar ko lactic acid me badal deta hai, jisse dahi jamta
hai.
*Q3. Do useful microorganisms ke naam + kaam likho.*
Yeast – bread banana. Rhizobium – mitti me nitrogen fix karna.
*Q4. Virus ko zinda aur murda ke beech kyun kaha jata hai?*
Kyunki virus khud se badh nahi sakta, sirf host cell ke andar jaake badhta hai.
*Q5.
Q5. Hum khane ki cheezon ko microbes se kaise bacha sakte hain?*
Khana dhak ke rakho, fridge me rakho, bache hua khana dobara garam karke khao.
_Exam-Focused Notes_
*1. Definition*
*Hindi:* _Sukshmajeev_ wo chhote jeev hain jo aankh se nahi dikhai dete. Inhe
microscope se dekha jata hai. Ye hawa, pani, mitti aur hamare sharir me har jagah milte
hain.
*English:* Microorganisms are tiny living beings not visible to the naked eye. They are
seen under a microscope. They are found everywhere – in air, water, soil, and inside our
bodies.
*2. Key Points*
- Microorganisms 4 types ke hote hain: *Bacteria, Fungi, Protozoa, Algae* + *Virus*
- Kuch microorganism *useful* hain: Dahi jamana, bread banana, dawai banana, mitti ko
upjau banana
- Kuch *harmful* hain: bimari failana – TB, Cholera, Malaria
- *Lactobacillus* bacteria se dahi jamta hai
- *Yeast* fungi se bread phoolta hai
- *Nitrogen-fixing bacteria* mitti me nitrogen badhate hain
- Virus sirf living cell ke andar hi badh sakta hai. Isliye ise zinda aur murda ke beech
mana jata hai
- Harmful microbes se bachne ke liye khana dhak ke rakho, pani ubal ke piyo, vaccine
lagwao
*3. Diagram Description*
_Bacteria ka structure:_ Chhota, chhadi jaisa ya gol shape. Bahar ek cell wall, andar
cytoplasm aur DNA. Kuch bacteria me baal jaisi structure “flagella” hoti hai jo hilne me
madad karti hai.
*4. Important Q&A for Exam*
*Q1. Microorganisms kise kahte hain?*
Jeev jo aankh se nahi dikhte, microscope se dekhe jate hain.
*Q2. Dahi kaise jamta hai?*
Lactobacillus bacteria doodh me sugar ko lactic acid me badal deta hai, jisse dahi jamta
hai.
*Q3. Do useful microorganisms ke naam + kaam likho.*
Yeast – bread banana. Rhizobium – mitti me nitrogen fix karna.
*Q4. Virus ko zinda aur murda ke beech kyun kaha jata hai?*
Kyunki virus khud se badh nahi sakta, sirf host cell ke andar jaake badhta hai.
*Q5.
Q5. Hum khane ki cheezon ko microbes se kaise bacha sakte hain?*
Khana dhak ke rakho, fridge me rakho, bache hua khana dobara garam karke khao.
