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🇵🇰 BDS Admission Test · flashcards
BDS Admission Test Biology Flashcards
60 question-and-answer cards covering Biology as it is examined in BDS Admission Test. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Biology deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
Describe the fluid mosaic model of the cell membrane.
A phospholipid bilayer (fluid) with proteins (mosaic) embedded in or attached to it, plus cholesterol and glycoproteins/glycolipids; components can move laterally.
What is diffusion?
The net movement of particles from a region of higher concentration to a region of lower concentration, down a concentration gradient, until equilibrium; passive (no ATP).
Define osmosis.
The net movement of water molecules from a region of higher water potential to lower water potential across a partially (selectively) permeable membrane; passive.
What is facilitated diffusion?
Passive transport of substances across a membrane through specific carrier or channel proteins, down the concentration gradient, without using ATP.
How does active transport differ from diffusion?
Active transport moves substances against their concentration gradient using carrier proteins and energy (ATP), whereas diffusion is passive and moves down the gradient.
Distinguish between endocytosis and exocytosis.
Endocytosis is bulk uptake of material into the cell by engulfing it in a vesicle; exocytosis is bulk release of material out of the cell via vesicles fusing with the membrane. Both require ATP.
What is the function of mitochondria, and what feature increases their efficiency?
Site of aerobic respiration (ATP production); the inner membrane is folded into cristae to increase surface area, and they contain their own DNA.
State the function of ribosomes and their two locations.
Ribosomes are the site of protein synthesis (translation); found free in the cytoplasm or attached to the rough endoplasmic reticulum.
Compare the functions of rough and smooth endoplasmic reticulum.
Rough ER (with ribosomes) synthesizes and transports proteins; smooth ER (no ribosomes) synthesizes lipids and steroids and helps detoxification.
What is the function of the Golgi apparatus?
Modifies, sorts, packages, and secretes proteins and lipids, and forms lysosomes; it produces secretory vesicles.
What are lysosomes and their function?
Membrane-bound vesicles containing hydrolytic (digestive) enzymes that break down worn-out organelles, waste, and engulfed material (autophagy and intracellular digestion).
What is the role of chloroplasts, and where is chlorophyll located?
Site of photosynthesis in plant cells; chlorophyll is found in the thylakoid membranes (stacked into grana), surrounded by the stroma.
What are the functions of the nucleus?
It controls cell activities, stores genetic material (DNA), and is the site of DNA replication and transcription; the nucleolus within it makes ribosomes.
What is a chromosome, and what is it made of?
A chromosome is a condensed structure of DNA wound around histone proteins (forming chromatin); it carries the genes and becomes visible during cell division.
What is the difference between chromatin and a condensed chromosome?
Chromatin is the loosely coiled, uncondensed DNA-protein complex seen during interphase; a chromosome is the highly condensed, visible form during cell division.
What is an enzyme, chemically?
A biological catalyst, mostly globular protein, that speeds up the rate of a biochemical reaction by lowering activation energy, without being used up or altering the equilibrium.
What is the active site of an enzyme?
A specific region (a cleft or groove) on the enzyme, with a shape complementary to the substrate, where the substrate binds and the reaction is catalyzed.
How do enzymes speed up reactions?
By lowering the activation energy required for the reaction to proceed, allowing it to occur faster at lower temperatures.
Explain the 'lock and key' model of enzyme action.
The substrate (key) has a shape exactly complementary to the rigid active site (lock); only a specific substrate fits, explaining enzyme specificity.
Explain the 'induced fit' model of enzyme action.
The active site is flexible and changes shape slightly to mould around the substrate when it binds, straining bonds and catalyzing the reaction; a refinement of the lock-and-key model.
What is an enzyme-substrate complex?
The temporary intermediate structure formed when the substrate binds to the enzyme's active site, before products are formed and released.
How does temperature affect enzyme activity?
Rate increases with temperature up to an optimum (more kinetic energy/collisions); beyond the optimum, the enzyme denatures and activity falls sharply.
How does pH affect enzyme activity?
Each enzyme has an optimum pH at which activity is maximal; deviations alter charges and bonds in the active site, reducing activity, and extreme pH causes denaturation.
Distinguish between competitive and non-competitive enzyme inhibitors.
Competitive inhibitors resemble the substrate and bind the active site (effect reduced by more substrate); non-competitive inhibitors bind elsewhere (allosteric site), changing the active site's shape (not overcome by more substrate).
What this deck covers
The Biology deck follows the BDS Admission Test Biology syllabus — 10 chapters and 37 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 6.0 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 158 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Biology flashcards FAQ
How many Biology flashcards are in this BDS Admission Test deck?
60 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these BDS Admission Test flashcards free?
Yes. The preview here is free to read with no signup, and the full 60-card deck is free inside the Examius app.
What do the Biology cards cover?
They follow the BDS Admission Test Biology syllabus — 10 chapters and 37 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.