NEET · Biology doubts
340 doubts found
What does “Cell theory” actually mean in Cell: The Unit of Life, and why does it matter for NEET?
all living organisms are made of cells, and every cell arises from a pre-existing cell.
What does “Enzymes” actually mean in Biomolecules, and why does it matter for NEET?
biological catalysts (mostly proteins) that speed reactions by lowering activation energy.
What does “Phases of the cell cycle” actually mean in Cell Cycle & Cell Division, and why does it matter for NEET?
G1 (growth), S (DNA replication), G2 (growth) make up interphase, followed by M phase (division).
What does “Light reactions” actually mean in Photosynthesis in Higher Plants, and why does it matter for NEET?
occur in the thylakoid membranes, using light to make ATP and NADPH and releasing O₂ by splitting water.
What does “Glycolysis” actually mean in Respiration in Plants, and why does it matter for NEET?
the splitting of glucose into two pyruvate molecules in the cytoplasm, giving a net of 2 ATP.
What does “Digestive enzymes” actually mean in Digestion & Absorption, and why does it matter for NEET?
amylase breaks starch, pepsin and trypsin break proteins, and lipase breaks fats — each in its own region.
What does “Gas exchange” actually mean in Breathing & Exchange of Gases, and why does it matter for NEET?
oxygen and carbon dioxide swap by diffusion across the thin, moist walls of the alveoli.
What does “Double circulation” actually mean in Body Fluids & Circulation, and why does it matter for NEET?
blood passes through the heart twice in one complete circuit — once to the lungs, once to the body.
What does “Nephron” actually mean in Excretory Products & Elimination, and why does it matter for NEET?
the microscopic filtering unit of the kidney where urine formation begins.
What does “Neuron” actually mean in Neural Control & Coordination, and why does it matter for NEET?
the nerve cell that carries impulses, with dendrites (receive), an axon (transmit) and synapses (connect).
What does “Hormones” actually mean in Chemical Coordination (Endocrine System), and why does it matter for NEET?
chemical messengers released by ductless (endocrine) glands into the blood to act on target organs.
What does “Mendel's laws” actually mean in Principles of Inheritance & Variation, and why does it matter for NEET?
the laws of dominance, segregation, and independent assortment govern how traits pass to offspring.
What does “DNA structure” actually mean in Molecular Basis of Inheritance, and why does it matter for NEET?
a double helix held by complementary base pairing: adenine with thymine, guanine with cytosine.
What does “Natural selection” actually mean in Evolution, and why does it matter for NEET?
individuals best adapted to their environment survive and reproduce more, so their traits spread.
What does “Innate vs acquired immunity” actually mean in Human Health & Disease, and why does it matter for NEET?
innate immunity is the non-specific defence we're born with; acquired immunity is specific and develops after exposure.
What does “Gametogenesis” actually mean in Human Reproduction & Reproductive Health, and why does it matter for NEET?
the formation of gametes — spermatogenesis makes four sperm per cell, oogenesis makes one ovum plus polar bodies.
What does “Recombinant DNA technology” actually mean in Biotechnology & its Applications, and why does it matter for NEET?
inserting a desired gene into a vector and then a host cell to mass-produce a useful product.
What does “Energy flow” actually mean in Ecosystem & Ecology, and why does it matter for NEET?
energy moves one-way through an ecosystem — from the sun to producers to consumers — and is lost as heat at each step.
Why aren't viruses placed in any of the five kingdoms of life?
The five-kingdom system classifies cellular organisms, but a virus isn't a cell at all — it's just nucleic acid (DNA or RNA) wrapped in protein.
Is a potato a root or a stem — and how can you actually tell?
A potato is a modified underground STEM (a stem tuber), not a root.
How can you tell a tree's age (and past climate) from the rings in its trunk?
A dicot tree thickens each year as the vascular cambium adds a new layer of wood.
How does water reach the leaves at the top of a 100-metre-tall tree with no pump?
As leaves transpire, water evaporates from their surfaces and creates a suction (negative pressure) in the xylem.
Why does pinching off the top shoot of a plant make it grow bushier?
The growing tip produces auxin, which travels down and suppresses the side (lateral) buds — this is apical dominance.
What actually happens inside a muscle when it contracts to lift something?
A nerve signal releases calcium ions inside the muscle fibre, which expose binding sites on the thin actin filaments.