Key Biological Processes and Concepts Explained
Key Biological Processes
Transcription, Translation, and Translocation
Transcription: The process of RNA synthesis.
Translation: Amino acids are supplied by tRNA according to the message on mRNA. tRNA has an ‘anticodon’ with a complementary sequence to the codon on mRNA.
Translocation: The ribosome moves along the mRNA by the distance of one triplet codon.
Central Dogma: The process of protein synthesis from DNA through RNA.
Important Biological Molecules
NAD: Nicotinamide Adenine Dinucleotide
FAD: Flavin Adenine Dinucleotide
Glycolysis: Produces 2 molecules of NADH2 and 2 molecules of CO2.
TCA Cycle: Produces molecules of CO2, H2O, NADH2, and FADH2.
Aerobic Respiration: Produces CO2 and H2O with energy.
Reproduction Methods
Fragmentation
The body of the parent organism breaks into many fragments, and each fragment lives as an independent new organism. Examples: Spirogyra and Sycon.
Regeneration
An animal, such as Planaria, breaks its body into two parts, and each part regenerates the remaining part of the body, forming two new Planaria.
Budding
Hydra reproduces through budding under specific conditions. An outgrowth forms by repeated division of regenerative cells of the body wall. This bud grows and forms a small Hydra.
Vegetative Propagation
Reproduction in plants using vegetative parts like roots, stems, leaves, and buds. Examples: Bryophyllum, carrots, and radishes.
Spore Formation
Fungi like Mucor have filamentous bodies with sporangia. Once spores form, the sporangia burst, releasing the spores. Spores germinate in moist and warm places, forming new fungal colonies.
Reproductive Health
Reproductive health is a state of physical, mental, and social well-being. The menstrual cycle is related to reproductive and overall health in women. Maintaining cleanliness of genitals is essential to protect against sexual diseases like syphilis and gonorrhea, which are caused by bacteria.
Assisted Reproductive Technologies
In Vitro Fertilization (IVF)
Fertilization occurs in a test tube, and the resulting embryo is implanted in the woman’s uterus at the appropriate time.
Surrogacy
An oocyte is collected from a woman with implantation problems, and sperm is collected from her husband. Fertilization occurs in a test tube, and the embryo is implanted in the uterus of another woman (a surrogate mother) with a normal uterus.
Sperm Bank
Semen is collected from desired men and stored in a sperm bank.
Environmental Conservation
Chipko Movement
In the 1970s, an opposition to forest destruction spread throughout India, known as the Chipko movement. The name comes from the word ’embrace,’ as villagers hugged trees to prevent contractors from felling them. The Bishnoi community of Rajasthan also has a history of saving nature. Around 260 years ago, a large group of villagers led by Amrita Devi sacrificed their lives to protect trees from being felled on the orders of the Maharaja of Jodhpur.
Biodiversity
Genetic Diversity
Genetic diversity is the occurrence of diversity among organisms of the same species. Example: Each human being is different. A decrease in diversity within a species that reproduces sexually can lead to the possibility of wiping out the species.
Species Diversity
Innumerable species of organisms occur in nature.
Ecosystem Diversity
Many ecosystems are present in each region, formed through the interaction between plants, animals, their habitat, and environmental changes. Each ecosystem has its own characteristic animals, plants, microbes, and abiotic factors. Ecosystems are either natural or artificial.
Effects of Radiation
- Cancerous ulceration occurs due to higher radiation from X-rays.
- Tissues in the body are destroyed.
- Genetic changes occur.
- Vision is adversely affected.
Environmental Stewardship
Jadhav Molai
In 1979, the local social forestry Department in Assam began a social afforestation project on 200 hectares of land. Even after the project’s completion, Molai continued to plant trees single-handedly. Currently, the barren area is covered with trees across approximately 1360 acres. This demonstrates that even if many people destroy a forest, a single determined person can make a difference and create a new forest.
Animal Symmetry
Asymmetrical Body
There is no imaginary axis through which the body can be divided into two equal halves. Examples: Amoeba, Paramecium, some sponges.
Radial Symmetry
An imaginary cut through the central axis of any plane of the body yields two equal halves. Example: Starfish. In starfish, five different planes pass through the central axis, allowing for two equal halves.
Bilateral Symmetry
There is only one imaginary axis through which the body can be divided into two equal halves. Examples: Insects, fishes, frogs, birds, humans.
Microbiology
Yoghurt: Streptococcus thermophilus, Lactobacillus delbrueckii
Cheese: Lactobacillus lactis, Lactobacillus cremoris, Streptococcus
Probiotics: e.g., Lactobacillus acidophilus, Lactobacillus desai
Bread: Saccharomyces cerevisiae
Microbial Enzymes: Oxidoreductases, transferases, hydrolases, lyases, isomerases
Microbes and Fuels
- Gaseous fuel (methane) can be obtained by microbial anaerobic decomposition of urban, agricultural, and industrial waste.
- Ethanol, a clean (smokeless) fuel, is obtained during fermentation of molasses by the yeast Saccharomyces.
- Hydrogen gas is considered the fuel of the future, released during bio-photolysis of water by bacteria.