Diversity in the living word
What is the basic unit of classification in biology?
Species
Who discovered the cell and what did he use to observe it?
Robert Hooke; used a self-designed microscope to observe cork cells in 1665.
Name the four types of animal tissue.
Epithelial, Connective, Muscular, Nervous
Name the four major types of biomolecules found in living organisms
Carbohydrates, Proteins, Lipids, Nucleic acids
In Class 10 you studied the nephron. Name the two processes (other than filtration) that occur in the nephron.
Reabsorption (of useful substances back into blood) and Secretion (of wastes into the filtrate).
Name the five kingdoms of life proposed by R.H. Whittaker.
Monera, Protista, Fungi, Plantae, Animalia
What is the difference between a plant cell and an animal cell? Name two differences.
Plant cell: has cell wall, chloroplasts, large central vacuole. Animal cell: has centrioles, no cell wall, smaller vacuoles.
What is meristematic tissue in plants? Where is it found?
Actively dividing tissue responsible for plant growth. Found at root tips, shoot tips, and in the cambium.
What is the monomer of proteins? How are two monomers joined?
Amino acids — joined by peptide bonds.
What is the difference between pulmonary and systemic circulation in humans?
Pulmonary: heart to lungs and back (for oxygenation). Systemic: heart to rest of body and back (delivers oxygen to tissues).
A mushroom has a cell wall but no chlorophyll. Which kingdom does it belong to and how does it get nutrition?
Fungi — it absorbs nutrients from dead or living organic matter (saprophytic/heterotrophic)
What is the function of the Golgi apparatus?
It packages and transports proteins and other molecules, and produces lysosomes.
Which animal tissue connects bones to bones, and which connects muscles to bones?
Ligament connects bone to bone; Tendon connects muscle to bone. Both are connective tissues.
What is the difference between smooth and rough endoplasmic reticulum?
Rough ER: has ribosomes, involved in protein synthesis. Smooth ER: no ribosomes, involved in lipid synthesis and detoxification.
What is the role of bile in digestion? Where is it produced , stored and where does it act?
Bile emulsifies fats. Produced in liver, stored in gall bladder, acts in the small intestine.
What is binomial nomenclature? Who proposed it?
A two-part scientific naming system (genus + species). Proposed by Carl Linnaeus.
Distinguish between prokaryotic and eukaryotic cells with two differences and one example each
Prokaryotic: no membrane-bound nucleus, no organelles (e.g. bacteria). Eukaryotic: membrane-bound nucleus, organelles present (e.g. human cells).
What is the difference between striated, smooth, and cardiac muscle? Give the location of each.
Striated (skeletal): voluntary, arms/legs. Smooth: involuntary, stomach/intestines. Cardiac: involuntary, rhythmic, only in the heart.
What are enzymes and why are they called biological catalysts?
Enzymes are proteins that speed up chemical reactions in the body without being consumed in the process.
Compare breathing mechanisms of fish (gills), frogs (skin+lungs), and humans (lungs). What does this tell us about evolution?
Fish use gills for dissolved O2. Frogs use moist skin and simple lungs. Humans have complex alveolar lungs. Shows increasing complexity with terrestrial adaptation.
"A whale lives in water and breathes like you do. A shark lives in water and breathes through gills. A dolphin gives birth to live young. A salmon lays eggs. Using just these four clues — which two animals are more closely related to each other than to the other two, and why?"
Whale and dolphin — both are mammals (breathe air with lungs, give birth to live young, warm-blooded). Shark and salmon are both fish. This shows that where an animal lives does not determine its classification — internal biology does.
What is the difference between mitosis and meiosis in terms of chromosome number and purpose?
Mitosis: same chromosome number, for growth/repair. Meiosis: halves chromosome number, for production of gametes.
Compare the structure and function of cartilage and bone. Both are connective tissues — what makes bone harder, and where would you find cartilage in the human body today?"
Bone has a matrix hardened by calcium and phosphate salts making it rigid. Cartilage has a flexible protein matrix with no mineral salts. Cartilage is found at the tip of the nose, ear pinna, between vertebrae, and at the ends of bones (joints).
You eat a samosa. By the time its nutrients reach your bloodstream, the big starchy molecules have been broken into tiny pieces. What is the monomer of starch, what enzyme breaks it down, and — here's the fun part — where in your body does this digestion actually begin?"
Monomer = glucose. Enzyme = amylase. Digestion begins in the MOUTH — salivary amylase starts breaking starch the moment you chew. (That's why if you chew plain rice long enough it starts tasting sweet!)
You're watching a scary movie and suddenly your heart starts pounding, your palms get sweaty and your mouth goes dry — even though you're just sitting on a couch doing nothing. Which hormone caused all of this, and why is your body being so dramatic over a fictional movie? What other effects are seen?
Adrenaline, released by the adrenal glands. Your brain perceived a threat (even a fake one) and triggered the fight or flight response. Higher heart rate, breathing rate, sweating , more blood to muscles