CAIE IGCSE Biology (0610) Theory - Vocabulary Flashcards (Video Notes)

A set of vocabulary flashcards drawn from the lecture notes to help review key terms and definitions for CAIE IGCSE Biology (0610).

Movement

A movement or change of position of an organism or part of it.

Respiration (definition in notes)

Chemical reactions in cells that break down nutrients and release energy for metabolism.

Sensitivity

The ability to detect and respond to changes in the internal or external environment.

Growth (in biology)

A permanent increase in size and dry mass.

Reproduction (general)

The process which produces offspring genetically identical or different from the parent.

Excretion

The removal of waste products of metabolism and substances in excess of requirements.

Nutrition (biological)

The taking in of materials for energy, growth, and development.

MRS GREN

Mnemonic for Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.

Kingdom (classification)

A high-level group in the classification sequence used to classify organisms.

Phylum

A level in the classification sequence below Kingdom and above Class.

Class

A grouping in taxonomy; between Phylum and Order.

Order

A taxonomic rank below Class and above Family.

Family

A taxonomic rank below Order and above Genus.

Genus

A group of related species; the first part of a binomial name.

Species

A group of organisms capable of reproducing to produce fertile offspring.

Binomial nomenclature

Two-part internationally agreed naming system: Genus + species; genus capitalized, species lowercase.

Genus (in binomial name)

The first word in the scientific name; capitalized.

Species (in binomial name)

The second word in the scientific name; not capitalized.

DNA

Deoxyribonucleic acid; long molecule in chromosomes that carries genetic information.

Adenine (A)–Thymine (T) pairing

DNA base pairing rule: A pairs with T.

Cytosine (C)–Guanine (G) pairing

DNA base pairing rule: C pairs with G.

Dichotomous keys

A classification method that uses two contrasting choices to identify an organism.

Eukaryote

Organisms with cells that have a defined nucleus.

Prokaryote

Single-celled organisms without a true nucleus; often with plasmids.

Five Kingdoms (as described)

Animals, Plants, Fungi, Protists/Protoctists, Prokaryotes (Monera).

Protoctist/Protist

Single-celled organism with a nucleus; eukaryote; some are multicellular.

Five Vertebrate groups

Mammals, Reptiles, Fish, Amphibians, Birds.

Vertebrate

Animals with a backbone.

Invertebrate

Animals without a backbone.

Arthropod

Invertebrates with an exoskeleton, jointed legs, and segmented bodies.

Crustacean

Arthropod with 5 pairs of legs (one pair modified as claws) and a carapace.

Insect

Arthropod with 3 pairs of legs; typically 2 pairs of wings; body in head, thorax, abdomen.

Arachnid

Arthropod with 4 pairs of legs; cephalothorax and abdomen.

Myriapod

Many-legged arthropod.

Fern (plant type)

Non-flowering plant that reproduces by spores; fronds leaflets.

Monocotyledon

Flowering plant with one seed leaf; parallel veins; scattered vascular bundles; petals in multiples of 3.

Dicotyledon

Flowering plant with two seed leaves; branched veins; petals in multiples of 4 or 5.

Virus

Not living by itself; uses host cells to reproduce; contains genetic material in a protein coat.

Cell membrane

Selective boundary of a cell that controls movement of substances in/out.

Cytoplasm

Jelly-like internal substance where metabolic reactions occur.

Nucleus

Organelle containing DNA and controlling cell activities.

Mitochondria

Organelle where aerobic respiration occurs and energy is released.

Ribosome

Organelle where protein synthesis occurs.

Endoplasmic reticulum

Membrane network with ribosomes (rough) or without (smooth).

Vacuole (plant cells)

Cell organelle containing cell sap to keep the cell turgid.

Cell wall

Rigid layer in plant cells that provides support and shape (not in animal cells).

Chloroplast

Organelle containing chlorophyll; site of photosynthesis.

Xylem

Plant tissue that transports water/mineral ions; thick lignified walls; dead cells.

Phloem

Plant tissue that transports sugars and amino acids; living cells.

Transpiration

Loss of water vapour from leaves via stomata; driven by a transpiration pull.

Translocation

Movement of sucrose and amino acids in the phloem from sources to sinks.

Root hair cell

Specialised plant cell with a large surface area for water/mineral uptake.

Stomata

Pores on leaf surface; open/close to regulate gas exchange and water loss.

Guard cells

Cells that control the opening and closing of stomata.

Photosynthesis

Process by which plants make carbohydrates from CO2 and water using light.

Chlorophyll

Green pigment that traps light energy for photosynthesis.

Starch

Storage carbohydrate produced in Photosynthesis; energy reserve.

Enzyme

Biological catalyst; speeds up reactions and is unchanged at the end.

Active site

Part of an enzyme where the substrate binds.

Lock and Key model

Hypothesis that substrates fit precisely into enzyme active sites.

Optimum temperature

Temperature at which an enzyme works best; about 37°C in humans.

Denaturation

When an enzyme loses its shape and function due to heat or pH changes.

pH on enzymes

Enzymes have optimum pH; changing pH can denature them.

Pepsin

Digestive enzyme working best in acidic conditions.

Amylase

Digestive enzyme that breaks down starch; works in neutral conditions.

Trypsin

Digestive protease that works best in alkaline conditions.

Bile

Alkaline digestive juice that emulsifies fats and neutralizes stomach acid.

Hydrochloric acid (in stomach)

Creates acidic conditions; denatures microbes and provides optimum pH for pepsin.

Villi and microvilli

Folded structures in the small intestine that increase absorption area.

Lacteal

A lymphatic vessel in a villus that absorbs fats (lipids).

Capillary

Small blood vessel where nutrient exchange occurs; site of diffusion into blood.

Osmosis

Net movement of water molecules from high to low water potential across a partially permeable membrane.

Diffusion

Net movement of particles from a region of high concentration to low concentration.

Passive transport

Movement of substances across membranes without energy (diffusion/osmosis).

Active transport

Movement of particles against the concentration gradient using energy (ATP).

Glucose oxidation (respiration)

Process by which glucose is broken down to release energy (aerobic/anaerobic).

Aerobic respiration

Cellular respiration that uses oxygen to fully break down glucose, releasing more energy.

Anaerobic respiration

Respiration without oxygen; less energy and produces lactic acid in animals or ethanol/CO2 in yeast.

Urea

Toxic waste produced from amino acid deamination in the liver.

Kidney nephron

Functional unit of the kidney where ultrafiltration and reabsorption occur.

Ultrafiltration

Blood in glomerulus is filtered; filtrate passes into Bowman's capsule while cells/large proteins stay in blood.

Selective reabsorption

Tubule reclaims most salts, water, and glucose back into blood.

Loop of Henle

Part of nephron that is permeable to water; concentrates urine via osmosis.

Collecting duct

Region where final urine composition is adjusted before excretion.

Homeostasis

Maintenance of a constant internal environment; uses negative feedback.

Negative feedback

A control mechanism where a response reduces the initial stimulus to restore balance.

Hormones

Chemical messengers released by glands; travel in blood to target organs.

Insulin

Hormone that lowers blood glucose by promoting storage as glycogen in the liver.

Glucagon

Hormone that raises blood glucose by converting glycogen to glucose.

Oestrogen

Female sex hormone involved in sexual development and regulation of the menstrual cycle.

Progesterone

Hormone that maintains the lining of the uterus in the middle of the cycle and during pregnancy.

FSH

Follicle-stimulating hormone; stimulates egg maturation and oestrogen release.

LH

Luteinising hormone; triggers ovulation and formation of the corpus luteum.

Menstrual cycle

Regular natural changes in the female reproductive system involving hormones, ovulation, and menstruation.

Fertilisation

Fusion of sperm and egg nuclei to form a zygote.

Zygote

Product of fertilisation; a fertilized egg that develops into an embryo.

Gamete

Sex cell (sperm or ovum) containing half the number of chromosomes.

Punnett square

Genetic diagram used to predict offspring genotypes in a cross.

Codominance

When two alleles are equally expressed in the phenotype (e.g., ABO blood groups).

Sex-linked inheritance

Genetic traits carried on sex chromosomes; often more common in one sex.