UP Board Class 12 Biology Question Paper 2023 with Answer Key and Solutions PDF (February 27, Code 348 CH)

Step 1: Understanding ovule structure.

The ovule is attached to the placenta of the ovary by a stalk called the funicle. The point where the funicle and the body of the ovule meet is a distinct scar-like mark.


Step 2: Define Hilum.

This mark of attachment is called the hilum. It is essentially the junction point where the seed remains attached to the ovary wall via the funicle.


Step 3: Eliminate incorrect options.

- (A) Micropyle: Small opening at one end of the ovule, not the attachment point.

- (B) Chalaza: Opposite end of the micropyle, where integuments and nucellus meet.

- (D) Egg cell: Female gamete inside the embryo sac, not related to attachment.


Step 4: Conclusion.

Therefore, the correct answer is (C) Hilum.
Quick Tip: Hilum is the scar on a seed showing the point of attachment of the funicle to the ovule.

Step 1: Understanding T.B. (Tuberculosis).

Tuberculosis is a bacterial disease caused by \emph{Mycobacterium tuberculosis, mainly affecting the lungs.

Step 2: Vaccine for T.B.

The vaccine given for prevention of tuberculosis is BCG (Bacillus Calmette–Guérin). It contains a weakened strain of \emph{Mycobacterium bovis.

Step 3: Eliminate incorrect options.

- (B) DPT: Used against Diphtheria, Pertussis (Whooping Cough), and Tetanus.

- (C) OPV: Oral Polio Vaccine, used against poliomyelitis.

- (D) Covaxin: COVID-19 vaccine.


Step 4: Conclusion.

Hence, the correct answer is (A) BCG.
Quick Tip: BCG vaccine is usually given soon after birth to protect infants from severe forms of tuberculosis.

Step 1: About Ramdev Mishra.

Prof. Ramdev Mishra is regarded as the Father of Ecology in India. He made significant contributions to the field of ecological studies, particularly in ecosystem analysis and biodiversity conservation.

Step 2: Analysis of options.

- (A) Ecology: Correct, as he is well-known as the father of Indian ecology.

- (B) Genetics: This is not associated with Ramdev Mishra.

- (C) Biotechnology: This is a modern field, not related to his contributions.

- (D) Human development: Again, not linked to his specialization.


Step 3: Conclusion.

Hence, the correct answer is (A) Ecology.
Quick Tip: Remember: Ramdev Mishra is often called the “Father of Indian Ecology” for his pioneering ecological research.

Step 1: Understanding Genetic Engineering.

Genetic engineering involves the manipulation of an organism’s DNA to introduce desirable traits, cure diseases, or enhance productivity.

Step 2: Applications in Medical Treatment.

In medicine, genetic engineering is used in gene therapy, production of insulin, vaccines, monoclonal antibodies, and treatment of genetic disorders.

Step 3: Applications in Agriculture.

In agriculture, it is used to create genetically modified (GM) crops such as Bt cotton, Bt maize, and Golden Rice, which are pest-resistant or nutritionally enriched.

Step 4: Conclusion.

Since genetic engineering is applied in both medical treatment and agriculture, the correct option is (C) Both (A) and (B).
Quick Tip: Genetic engineering is a powerful tool with applications in both healthcare (gene therapy, drugs) and agriculture (GM crops).

Step 1: Recall the photosynthesis reaction.
The overall equation is: \[ 6CO_2 + 6H_2O \xrightarrow{light\;energy,\;chlorophyll} C_6H_{12}O_6 + 6O_2 \]

Step 2: Identify the released gas.
In this process, water molecules undergo photolysis (splitting of water) and release oxygen gas.


Final Answer: \[ \boxed{Oxygen \,(O_2)} \] Quick Tip: During photosynthesis, the oxygen released comes from water, not from carbon dioxide.

Step 1: Enzyme action.
The enzymes responsible for breaking or cutting DNA are called **restriction endonucleases**.

Step 2: Mechanism.
- Restriction endonucleases recognize specific sequences of DNA and cut at those sites.
- Another enzyme, **DNase (deoxyribonuclease)**, can also non-specifically break down DNA into fragments.

Step 3: Correct enzyme.
When asked generally, the correct answer is DNase.


Final Answer: \[ \boxed{DNase (Deoxyribonuclease)} \] Quick Tip: Restriction endonucleases are used in genetic engineering, while DNase is a general enzyme that breaks DNA.

In humans, the sex chromosomes (X and Y) are responsible for sex determination.

- Females have two X chromosomes \((XX)\).

- Males have one X and one Y chromosome \((XY)\).


The sperm determines the sex of the offspring:

- If the sperm carries an \(X\) chromosome \(\Rightarrow\) the child will be female \((XX)\).

- If the sperm carries a \(Y\) chromosome \(\Rightarrow\) the child will be male \((XY)\).



Final Answer:
\[ \boxed{Sex chromosomes (X and Y) determine sex in humans.} \] Quick Tip: The Y chromosome carries the SRY (sex-determining region) gene that initiates male development.

Leydig cells (also called interstitial cells) are found in the testes, located between the seminiferous tubules. Their functions include:


1. Secretion of Testosterone:

- Main source of the male sex hormone testosterone.

- Testosterone regulates spermatogenesis and development of male secondary sexual characteristics.


2. Support in Puberty:

- Helps in the growth of facial hair, deepening of voice, and increase in muscle mass.


3. Maintenance of Male Reproductive Organs:

- Supports the functional integrity of male accessory organs such as the prostate gland and seminal vesicles.



Final Answer:
\[ \boxed{Leydig cells secrete testosterone and maintain male reproductive functions.} \] Quick Tip: Leydig cells are controlled by the luteinizing hormone (LH), which stimulates testosterone production.

A biodiversity hotspot is a biogeographic region that is rich in endemic species (species found nowhere else) but is also under significant threat due to human activities. The term was first introduced by Norman Myers in 1988, and later expanded by Conservation International.

According to Conservation International, a region qualifies as a biodiversity hotspot if:

It has at least 1,500 species of vascular plants as endemics.
It has lost at least 70% of its original habitat.


These regions cover only about 2.3% of Earth’s land surface but account for more than half of the world’s endemic plant species and a high proportion of mammals, birds, reptiles, and amphibians.

Examples:

Indo-Burma Region (including North-East India)
Himalaya (Entire Indian Himalayan Region and the Indo-Burma ranges)
Indo-Malayan Region (Nicobar Islands)
Tropical Andes, Amazon rainforest (global examples)



Final Answer: \[ \boxed{A biodiversity hotspot is a region rich in endemic species but under threat of habitat loss.} \] Quick Tip: Biodiversity hotspots are priority areas for conservation as they contain a large number of unique species but are highly vulnerable to extinction.

The Watson and Crick model of DNA shows a double helix structure in which:

- Two polynucleotide chains are coiled around each other.

- The sugar-phosphate backbone lies outside.

- Nitrogenous bases (A-T, G-C) pair through hydrogen bonds.

- The helix is right-handed.



Labelled Diagram:
\[ (Here you should draw a neat, labelled diagram showing: Sugar-Phosphate backbone, A-T base pair, G-C base pair, hydrogen bonds, double helix structure.) \] Quick Tip: Always label base pairs, hydrogen bonds, and sugar-phosphate backbone clearly in DNA diagrams.

Step 1: Example of STD.

One common sexually transmitted disease is **AIDS (Acquired Immuno Deficiency Syndrome)** caused by HIV (Human Immunodeficiency Virus).


Step 2: Control measures.

- Avoid unprotected sexual contact (use condoms).

- Ensure use of sterilized needles and avoid sharing syringes.

- Screen blood before transfusion.

- Create awareness through sex education.

- Infected individuals should receive proper medical treatment and counselling.



Final Answer: \[ \boxed{Example: AIDS. Control – safe sex, sterilized needles, screened blood, awareness.} \] Quick Tip: STDs can be prevented mainly by safe practices, awareness, and timely treatment.

1. Turner Syndrome:

- Individuals have a total of 45 chromosomes.

- Karyotype: \(45, XO\) (missing one sex chromosome).


2. Klinefelter Syndrome:

- Individuals have a total of 47 chromosomes.

- Karyotype: \(47, XXY\) (one extra X chromosome).



Final Answer:
\[ \boxed{Turner Syndrome: 45 chromosomes, \quad Klinefelter Syndrome: 47 chromosomes.} \] Quick Tip: Turner syndrome affects females (monosomy), while Klinefelter syndrome affects males (trisomy of sex chromosomes).

Definition:

Double fertilization is a unique process in flowering plants (angiosperms) in which two male gametes participate in fertilization inside the embryo sac.


- One male gamete fuses with the egg cell \(\Rightarrow\) forms the diploid zygote (2n).

- The other male gamete fuses with the two polar nuclei \(\Rightarrow\) forms the triploid endosperm (3n).


Thus, two fertilization events occur simultaneously, hence called double fertilization.


Discovery:

It was discovered by Sergey Nawaschin in 1898 in angiosperms.



Final Answer:
\[ \boxed{Double fertilization is the fusion of one male gamete with egg and another with polar nuclei, discovered by Sergey Nawaschin (1898).} \] Quick Tip: Double fertilization ensures both embryo and endosperm formation in the same embryo sac, making angiosperms highly efficient.

Mendel’s Law of Segregation, also known as the First Law of Inheritance, states that:
\[ “During the formation of gametes, the two alleles for a trait separate (segregate) so that each gamete receives only one allele.” \]

Step 1: Explanation.
- Each individual has two alleles for a trait (one from each parent).
- During gamete formation (meiosis), these alleles segregate randomly.
- Hence, each gamete carries only one allele for the given trait.
- Fertilization restores the pair of alleles in the offspring.

Step 2: Example (Monohybrid Cross).
Consider Mendel’s experiment with pea plants:
- Cross between a homozygous tall plant (TT) and a homozygous dwarf plant (tt).
- F\(_{1}\) generation: All plants are heterozygous (Tt), showing tallness.
- F\(_{2}\) generation (selfing of Tt): The ratio obtained is \[ Genotypic ratio: 1 \; TT : 2 \; Tt : 1 \; tt \] \[ Phenotypic ratio: 3 \; Tall : 1 \; Dwarf \]

This shows that alleles separate during gamete formation and recombine at fertilization.


Final Answer: \[ \boxed{Mendel’s Law of Segregation states that alleles separate during gamete formation, and each gamete receives only one allele.} \] Quick Tip: Remember: The Law of Segregation ensures \emph{purity of gametes}, as each gamete carries only one allele of a gene.

Step 1: Meaning of biofertilizers.

Biofertilizers are living microorganisms such as bacteria, fungi, and cyanobacteria that enrich the nutrient quality of the soil.


Step 2: Role in soil fertility.

- They fix atmospheric nitrogen into forms usable by plants (e.g., Rhizobium, Azotobacter).

- They solubilize phosphorus and make it available to plants (e.g., Pseudomonas, Bacillus).

- They decompose organic matter and release nutrients back into the soil.

- They improve soil structure and enhance water retention.



Final Answer:
\[ \boxed{Biofertilizers increase soil fertility by fixing nitrogen, solubilizing phosphorus, and recycling nutrients.} \] Quick Tip: Biofertilizers are eco-friendly alternatives to chemical fertilizers.

Step 1: Adaptations of desert plants (xerophytes).

- Thick cuticle and reduced leaves (spines) to minimize water loss.

- Stomata sunken or reduced in number.

- Photosynthesis through stems (e.g., cactus).

- Deep root systems to absorb groundwater.


Step 2: Adaptations of desert animals.

- Nocturnal lifestyle to avoid daytime heat.

- Ability to store water in body tissues (e.g., camel’s hump stores fat).

- Concentrated urine and dry feces to conserve water.

- Burrowing habits to escape extreme heat.



Final Answer:
\[ \boxed{Desert plants and animals show structural, physiological, and behavioral adaptations to conserve water and survive in hot, dry conditions.} \] Quick Tip: Xerophytes and desert animals survive mainly by water conservation strategies.

Definition:

Ascariasis is an intestinal infection caused by the roundworm Ascaris lumbricoides.


Symptoms:

- Abdominal pain, nausea, and diarrhea.

- Weakness, malnutrition, and in severe cases, intestinal blockage.


Prevention:

1. Proper sanitation and disposal of human feces.

2. Washing vegetables and fruits before eating.

3. Maintaining personal hygiene, like handwashing with soap.


Treatment:

- Anti-helminthic drugs such as albendazole or mebendazole are used to kill the worms.



Final Answer:
\[ \boxed{Ascariasis is caused by \textit{Ascaris lumbricoides, prevented by hygiene and treated with albendazole/mebendazole.} \] Quick Tip: Ascariasis spreads through contaminated food and water. Prevention is more effective than treatment.

Definition of Parthenogenesis:

Parthenogenesis is a form of reproduction in which an unfertilized egg develops into a new individual.


Mechanism of Sex Determination in Honeybees (Haplodiploidy):

- In honeybees, sex is determined by the ploidy of the individual.

- Fertilized eggs (diploid, 2n) develop into females (workers or queen).

- Unfertilized eggs (haploid, n) develop by parthenogenesis into males (drones).

- Thus, females are diploid and males are haploid. This system is called haplodiploid sex determination.



Final Answer:
\[ \boxed{Parthenogenesis is the development of an organism from an unfertilized egg. In honeybees, males (haploid) arise by parthenogenesis, females (diploid) from fertilized eggs.} \] Quick Tip: Haplodiploidy in honeybees ensures a high level of genetic relatedness among worker bees, aiding in social cooperation.

Definition:
Genetic engineering is a technique of directly manipulating an organism’s DNA by adding, removing, or modifying specific genes to obtain desired traits. It uses tools such as recombinant DNA technology, gene cloning, and CRISPR.

Applications in Health:

Production of Human Insulin: Using recombinant DNA technology, insulin-producing genes are introduced into bacteria (e.g., \emph{E. coli) to produce human insulin for diabetic patients.
Gene Therapy: Defective genes causing diseases (e.g., Severe Combined Immunodeficiency - SCID) are replaced or corrected by introducing healthy functional genes.



Final Answer: \[ \boxed{Genetic engineering is direct manipulation of genes, with health applications such as insulin production and gene therapy.} \] Quick Tip: Genetic engineering revolutionized medicine by enabling large-scale production of therapeutic proteins and development of personalized treatments.

\begin{tabular{|c|c|c|
\hline
Feature & DNA (Deoxyribonucleic Acid) & RNA (Ribonucleic Acid)
\hline
Sugar & Contains deoxyribose sugar & Contains ribose sugar
\hline
Structure & Double-stranded helix & Single-stranded
\hline
Nitrogen Base & Thymine (T) present & Uracil (U) replaces Thymine
\hline
\end{tabular


Final Answer: \[ \boxed{DNA differs from RNA in sugar, strand structure, and nitrogen bases.} \] Quick Tip: DNA stores genetic information, while RNA plays a key role in protein synthesis (mRNA, tRNA, rRNA).

Step 1: About human insulin.

Human insulin is a peptide hormone secreted by the \(\beta\)-cells of the pancreas (Islets of Langerhans). It regulates blood glucose levels by promoting the uptake of glucose into cells and converting it into glycogen.


Step 2: Structure.

Insulin is made up of two polypeptide chains – chain A (21 amino acids) and chain B (30 amino acids), linked together by disulfide bonds.


Step 3: Medical significance.

- In diabetic patients, the body either does not produce enough insulin (Type 1 diabetes) or cannot effectively use it (Type 2 diabetes).

- Recombinant DNA technology is used to produce human insulin artificially (Humulin) in bacteria like E. coli, which is used for treatment.



Final Answer:
\[ \boxed{Human insulin is a peptide hormone that regulates blood sugar, and recombinant insulin is used to treat diabetes. \] Quick Tip: Recombinant DNA technology made large-scale production of human insulin possible.

The life-cycle of Plasmodium (malaria parasite) involves two hosts:

- Human host: Asexual reproduction (schizogony) takes place in liver cells and red blood cells. This causes malaria symptoms.

- Female Anopheles mosquito: Sexual reproduction (sporogony) occurs in the mosquito, producing sporozoites that infect humans.



Diagram:

(Draw a labelled diagram showing the following stages: Sporozoite → Liver schizont → Merozoites → RBC infection (Trophozoite, Schizont, Gametocytes) → Mosquito gut (Zygote, Ookinete, Oocyst) → Sporozoites back to mosquito salivary gland).


Final Answer:
\[ \boxed{The malaria parasite completes its life-cycle in humans and female Anopheles mosquitoes. \] Quick Tip: Remember: Asexual cycle in humans, sexual cycle in mosquito.

Step 1: Introduction.

Gregor Johann Mendel, known as the "Father of Genetics," performed hybridization experiments on pea plants (Pisum sativum). His work explained how traits are passed from one generation to the next.


Step 2: Experimental Work.

- Mendel chose pea plants because they had distinct, contrasting traits (like tall/dwarf, round/wrinkled).

- He conducted monohybrid and dihybrid crosses.

- By analyzing the offspring, he discovered patterns of inheritance.


Step 3: Contributions (Laws).

1. Law of Segregation: Each individual carries two alleles for a trait, which segregate during gamete formation, ensuring each gamete receives one allele.

2. Law of Independent Assortment: Alleles of different traits assort independently during gamete formation.

3. Law of Dominance: When two contrasting alleles are present, one dominates (dominant trait) while the other is masked (recessive).


Step 4: Impact.

Although Mendel’s work was initially ignored, it was rediscovered in 1900 by Hugo de Vries, Correns, and von Tschermak. His principles became the foundation of classical genetics.



Final Answer:
\[ \boxed{Mendel discovered the fundamental laws of inheritance through pea plant experiments. \] Quick Tip: Mendel’s laws are applicable to all sexually reproducing organisms.

(i) Population and Community

Step 1: Define Population.

A population is a group of individuals of the same species living in a defined geographical area, interbreeding and sharing a common gene pool.


Step 2: Define Community.

A community is a group of populations of different species living in the same area, interacting with each other.


Step 3: Comparison.

\begin{tabular{|c|c|
\hline
Population & Community
\hline
Group of same species & Group of different species
\hline
Shares common gene pool & Includes many populations
\hline
Eg: Tigers in a forest & Eg: Tigers, deer, plants in a forest
\hline
\end{tabular


(ii) Hibernation and Aestivation

Step 1: Define Hibernation.

Hibernation is a state of dormancy during winter where animals reduce metabolic activity to survive cold and food scarcity. Eg: Bears, bats, hedgehogs.


Step 2: Define Aestivation.

Aestivation is a state of dormancy during summer where animals reduce activity to survive extreme heat and water shortage. Eg: Snails, lungfish.


Step 3: Comparison.

\begin{tabular{|c|c|
\hline
Hibernation & Aestivation
\hline
Occurs in winter & Occurs in summer
\hline
Protects from cold & Protects from heat
\hline
Eg: Bears, bats & Eg: Snails, fishes
\hline
\end{tabular


Final Answer:
\[ \boxed{Hibernation = winter sleep; Aestivation = summer sleep.} \] Quick Tip: Both are adaptations to survive extreme climatic conditions.

The Polymerase Chain Reaction (PCR) is a molecular biology technique used to amplify (make many copies of) a specific DNA sequence in vitro. It was developed by Kary Mullis in 1983.

Steps of PCR:

Denaturation: Double-stranded DNA is heated to about 94–96°C to separate into two single strands.
Annealing: The reaction is cooled to 50–65°C so that primers bind (anneal) to the complementary sequences on the DNA strands.
Extension: DNA polymerase (commonly Taq polymerase) extends the primers at about 72°C, synthesizing new DNA strands.


These steps are repeated in cycles (usually 25–35 cycles), leading to exponential amplification of DNA.

Applications: Used in disease diagnosis, forensic science, paternity testing, and genetic research.


Final Answer:
PCR is a method to amplify DNA sequences using repeated denaturation, annealing, and extension steps. Quick Tip: PCR requires primers, DNA polymerase, nucleotides, and a thermal cycler.

Polyembryony is the phenomenon of development of more than one embryo from a single fertilized egg (zygote). It may also occur due to the development of embryos from structures other than the zygote (e.g., nucellus or integuments).

Examples: Seen in plants like Citrus and Opuntia, and in some animals like armadillos.


(ii) Formation of Fruit

The fruit is a mature or ripened ovary, developed after fertilization. After fertilization, the ovary wall develops into the pericarp, and ovules develop into seeds.

Types of fruit formation:

True Fruit: Formed only from the ovary (e.g., Mango, Tomato).
False Fruit: Formed from ovary and other floral parts such as thalamus (e.g., Apple).
Parthenocarpic Fruit: Developed without fertilization, hence seedless (e.g., Banana). Quick Tip: Polyembryony ensures better survival chances, as more than one embryo may develop into viable offspring.

Step 1: Introduction.

The male reproductive system is specialized for the production, storage, and delivery of sperms and male sex hormones (androgens).


Step 2: Main Parts.

1. Testes: Primary male reproductive organs that produce sperms and testosterone.

2. Epididymis: Stores and matures the sperms.

3. Vas deferens: Transports sperms from the epididymis to the urethra.

4. Accessory glands: (Seminal vesicles, prostate gland, bulbourethral glands) secrete seminal fluid that nourishes and protects sperms.

5. Penis: Copulatory organ that delivers sperms into the female reproductive tract.



Diagram:

(A neat, labelled diagram of the male reproductive system should be drawn here showing testes, epididymis, vas deferens, seminal vesicles, prostate gland, urethra, and penis.)



Final Answer:

The male reproductive system includes testes, ducts, glands, and penis, all working together for sperm production and transfer. Quick Tip: Always label at least 5–6 parts in reproductive system diagrams to score full marks.

(i) Placenta formation

The placenta is a temporary organ formed during pregnancy between the uterine wall of the mother and the fetus.

- It develops from maternal tissues (endometrium) and embryonic tissues (chorion).

- It allows the exchange of gases, nutrients, and wastes between the mother and fetus.

- It also secretes hormones like hCG, progesterone, and estrogen to maintain pregnancy.



(ii) Red Data Book


The Red Data Book is a public record maintained by the International Union for Conservation of Nature (IUCN).

- It provides a list of endangered and threatened species of plants and animals worldwide.

- It classifies organisms into different categories such as extinct, endangered, vulnerable, rare, etc.

- It is a useful guide for biodiversity conservation.
Quick Tip: Remember: Placenta is both an excretory and nutritive organ.
The Red Data Book is crucial for planning conservation strategies.

Definition of Biodiversity:
Biodiversity refers to the variety of life forms on Earth, including different plants, animals, microorganisms, and the ecosystems they form. It represents the variability among species, between species, and within ecosystems.

Levels of Biodiversity:

Genetic Diversity: Variation of genes within species (e.g., different varieties of rice).
Species Diversity: Variety of species within a region (e.g., the Amazon rainforest).
Ecosystem Diversity: Diversity of ecosystems such as forests, deserts, wetlands, and grasslands.


Conservation of Biodiversity:

In-situ Conservation: Protection of species in their natural habitats (e.g., National Parks, Wildlife Sanctuaries, Biosphere Reserves).
Ex-situ Conservation: Conservation outside natural habitats (e.g., Botanical gardens, Zoos, Seed banks, Cryopreservation).
Legal Measures: Wildlife Protection Act, CITES, and awareness programs.



Final Answer:
Biodiversity is the variety of life on Earth, and its conservation is essential through in-situ and ex-situ methods. Quick Tip: Biodiversity maintains ecological balance, supports human survival, and must be conserved for future generations.

The genetic code is the set of rules by which the sequence of nucleotides in DNA or RNA is translated into proteins (sequence of amino acids). It is universal for almost all organisms, showing the unity of life.

Characteristics of Genetic Code:

Triplet Code: Each amino acid is coded by a sequence of three nucleotides called a codon.
Unambiguous: One codon codes for only one amino acid.
Degenerate: Multiple codons may code for the same amino acid (e.g., GGU, GGC, GGA, GGG all code for Glycine).
Universal: Same codons code for the same amino acids in all organisms.
Start and Stop Codons: AUG codes for Methionine (start codon), while UAA, UAG, and UGA act as stop codons.


Importance:
The genetic code ensures accurate protein synthesis, which is essential for cellular functions, growth, and inheritance. Mutations in the genetic code can lead to genetic disorders or variations.


Final Answer: \[ \boxed{The genetic code is a universal triplet code that directs protein synthesis in all organisms.} \] Quick Tip: Remember: AUG is the universal start codon, while UAA, UAG, and UGA are stop codons.

Microorganisms play an essential role in human welfare by contributing to food production, medicine, industry, and environmental balance. While some cause diseases, many are beneficial.

1. In Food Industry:

Fermentation: Yeast (\emph{Saccharomyces cerevisiae) is used in bread, alcohol, and wine production.
Dairy products: Lactic acid bacteria (\emph{Lactobacillus) are used in curd, cheese, and yogurt formation.


2. In Medicine:

Antibiotics: \emph{Penicillium notatum produces penicillin, the first antibiotic.
Vaccines: Microbes are used in the production of vaccines (e.g., BCG, Hepatitis B).


3. In Industry:

Enzymes: Microbes produce enzymes like amylase, lipase, and protease for detergents and food processing.
Organic Acids: \emph{Aspergillus niger produces citric acid; \emph{Acetobacter produces acetic acid (vinegar).


4. In Environment:

Biogas production: Methanogens produce methane gas from organic waste.
Bioremediation: Microbes degrade pollutants and oil spills. Quick Tip: Remember: Not all microbes are harmful—many are used in biotechnology, health, and environment management.

Definition:
Biotechnology is the use of living organisms, cells, or their components to develop useful products and processes for human welfare. It combines biology with technology.

Applications of Biotechnology:


Medical Applications:

Production of insulin, growth hormones, and vaccines through recombinant DNA technology.
Gene therapy to treat genetic disorders.


Agricultural Applications:

Genetically Modified (GM) crops like Bt cotton resistant to pests.
Tissue culture for producing disease-free, high-yielding plants.


Industrial Applications:

Production of enzymes, antibiotics, and vitamins.
Fermentation technology in food and beverages.


Environmental Applications:

Bioremediation: Using microbes to clean pollutants.
Biofuels: Production of biogas, ethanol, and hydrogen gas. Quick Tip: Biotechnology has revolutionized healthcare and agriculture, making processes more efficient and sustainable.