IGCSE Biology 0610 — Required Diagrams Study Lab

This is the complete list of biological diagrams you must be able to recognise and label for Cambridge IGCSE Biology (0610 / 0970), with the function of each structure. Use the interactive tool above to test yourself.

Cell Structure

Animal Cell (Figure 2.2)

• cell membrane — Partially permeable; controls what enters and leaves the cell.
• cytoplasm — Jelly-like fluid where most chemical reactions take place.
• nucleus — Contains DNA (genetic material); controls cell activities.
• mitochondria — Site of aerobic respiration that releases energy.
• ribosomes — Where proteins are made (protein synthesis).
• small vacuole / vesicle — Small temporary fluid-filled sac for storage or transport.

Plant Cell (Figure 2.3)

• cell wall — Made of cellulose; gives the cell shape and support.
• cell membrane — Partially permeable; controls movement in and out.
• nucleus — Contains DNA; controls the cell's activities.
• cytoplasm — Site of chemical reactions.
• vacuole — Large and permanent; full of cell sap; keeps the cell turgid.
• mitochondria — Site of aerobic respiration.
• chloroplast — Contains chlorophyll; site of photosynthesis.
• ribosomes — Site of protein synthesis.

Bacterial Cell (Figure 2.14)

• cell wall (peptidoglycan) — Supports and protects; made of peptidoglycan, NOT cellulose.
• cell membrane — Controls movement of substances in and out.
• cytoplasm — Contains enzymes; site of chemical reactions.
• ribosomes — Make proteins (protein synthesis).
• circular DNA — A single loop of DNA, not enclosed in a nucleus.
• plasmids — Small extra rings of DNA carrying additional genes.

Plant Structure & Transport

Transverse Section of a Leaf (Figure 6.11)

• cuticle — Waxy, waterproof layer that reduces water loss.
• upper epidermis — Transparent layer that lets light through; no chloroplasts.
• palisade mesophyll — Tall column cells packed with chloroplasts; main site of photosynthesis.
• spongy mesophyll — Loosely packed cells with air spaces for gas exchange.
• lower epidermis — Lower layer containing the stomata.
• guard cell — Pair of cells that open and close the stoma.
• stoma — Pore for gas exchange and water vapour loss.
• air space — Allows gases to diffuse to and from cells.
• xylem — Carries water and mineral ions up from the roots.
• phloem — Transports sucrose and amino acids (translocation).
• vascular bundle — Contains the xylem and phloem together.

Section Across a Plant Stem (Figure 8.4)

• epidermis — Outer protective layer of the stem.
• cortex — Packing tissue; can store substances and give support.
• vascular bundles (in a ring) — Contain xylem and phloem; arranged in a ring in stems.
• xylem — Carries water and mineral ions upward.
• phloem — Transports sucrose and amino acids.

Section Across a Plant Root (Figure 8.5)

• epidermis — Outer layer; some cells form root hairs.
• cortex — Stores starch and lets water pass to the centre.
• xylem (central) — In the centre of the root; carries water upward.
• phloem — Transports food substances around the plant.

Root Hair Cells (TS of root) (Figure 8.10)

• root hair — Long extension giving a large surface area for absorption.
• epidermis — Outer layer of root from which hairs grow.
• cortex — Tissue water passes through towards the xylem.

Human Nutrition

Human Digestive System (Figure 7.8)

• salivary glands — Secrete saliva containing amylase.
• oesophagus — Carries food to the stomach by peristalsis.
• stomach — Muscular bag; makes hydrochloric acid and pepsin; churns food.
• liver — Produces bile.
• gall bladder — Stores bile.
• bile duct — Carries bile to the duodenum.
• pancreas — Makes digestive enzymes and the hormone insulin.
• pancreatic duct — Carries pancreatic juice to the duodenum.
• duodenum — First part of the small intestine; digestion is completed.
• ileum — Lower small intestine; absorbs digested nutrients.
• colon — Part of the large intestine; absorbs water.
• rectum — Stores faeces before egestion.
• anus — Egestion (removal) of faeces.
• sphincter muscle — Ring of muscle controlling movement of material.

Structure of an Incisor Tooth (Figure 7.10)

• enamel — Hard, non-living outer layer that protects the tooth.
• dentine — Bone-like layer beneath enamel; contains living cytoplasm.
• pulp — Soft centre containing nerves and blood vessels.
• gum — Soft tissue surrounding the base of the tooth.
• cement — Holds the tooth in the jaw and anchors the fibres.
• fibres — Attach the tooth to the jawbone, allowing slight movement.
• jawbone — Bone that holds the tooth in its socket.
• blood supply — Brings oxygen and nutrients to the living tooth.

Four Types of Mammalian Teeth (Figure 7.11)

• incisors — Chisel-shaped; used for biting and cutting food.
• canines — Pointed teeth; in humans similar to incisors (tearing in carnivores).
• premolars — Have wide surfaces; used for grinding and chewing.
• molars — Large teeth used, like premolars, for grinding food.

Transport in Humans

The Human Heart (Heart diagram)

• right atrium — Receives deoxygenated blood from the vena cava.
• left atrium — Receives oxygenated blood from the pulmonary vein.
• right ventricle — Pumps deoxygenated blood to the lungs via the pulmonary artery.
• left ventricle — Pumps oxygenated blood to the body; has the thickest muscular wall.
• tricuspid valve — Right atrioventricular valve; stops backflow into the right atrium.
• bicuspid (mitral) valve — Left atrioventricular valve; stops backflow into the left atrium.
• semilunar valves — In the arteries; stop blood flowing back into the ventricles.
• tendons — Hold the valves so they do not turn inside out.
• septum — Wall separating the two sides of the heart.
• aorta — Carries oxygenated blood to the body.
• pulmonary artery — Carries deoxygenated blood to the lungs.
• pulmonary vein — Brings oxygenated blood back from the lungs.
• vena cava — Brings deoxygenated blood back from the body.

Plan of the Main Blood Vessels (Figure 9.16)

• aorta — Main artery carrying oxygenated blood from the heart to the body.
• vena cava — Main vein returning deoxygenated blood to the heart.
• pulmonary artery — Carries deoxygenated blood from heart to lungs.
• pulmonary vein — Carries oxygenated blood from lungs to heart.
• renal artery — Carries blood to the kidney.
• renal vein — Carries blood away from the kidney.
• artery to / vein from liver — Hepatic vessels supplying and draining the liver.

Components of Blood (Figure 9.18)

• red blood cell — Biconcave, no nucleus; full of haemoglobin to carry oxygen.
• white blood cell — Has a nucleus; defends against pathogens.
• platelets — Small cell fragments with no nucleus; help blood to clot.
• plasma — Pale yellow liquid that transports cells and dissolved substances.
• haemoglobin — Red pigment in red cells that binds oxygen.

Gas Exchange

Human Gas Exchange System (Figure 11.3)

• larynx — Voice box at the top of the trachea.
• trachea — Windpipe; carries air, held open by rings of cartilage.
• cartilage — Keeps the trachea open during breathing.
• bronchus — Branch of the trachea leading into a lung.
• bronchiole — Smaller airway branching from a bronchus.
• alveoli (air sacs) — Site of gas exchange between air and blood.
• pleural membranes — Surround the lungs and reduce friction.
• pleural fluid — Lubricates the pleural membranes.
• diaphragm — Muscle that flattens during inhalation.
• external intercostal muscle — Contracts to raise the ribs during inhalation.
• internal intercostal muscle — Contracts to lower the ribs during forced exhalation.

Coordination & Response

Sensory, Motor & Relay Neurones (Figure 12.6)

• sensory neurone — Carries impulses from receptors to the CNS.
• motor neurone — Carries impulses from the CNS to effectors (muscles/glands).
• relay neurone — Connects sensory and motor neurones within the CNS.
• cell body — Contains the nucleus.
• dendrites — Receive impulses from other neurones.
• axon — Carries the impulse along the neurone.
• myelin sheath — Insulates the axon and speeds up the impulse.

Section Through the Eye (Figure 12.10)

• conjunctiva — Thin layer protecting the front of the eye.
• cornea — Transparent front that refracts (bends) light.
• pupil — Hole that lets light into the eye.
• iris — Coloured ring that controls the size of the pupil.
• lens — Focuses light onto the retina; changes shape.
• ciliary muscle — Changes the shape of the lens (accommodation).
• suspensory ligament — Holds the lens in position.
• retina — Light-sensitive layer containing rods and cones.
• blind spot — Where the optic nerve leaves; has no receptors.
• optic nerve — Carries impulses from the retina to the brain.

Positions of Endocrine Glands (Figure 12.19)

• adrenal gland — Secretes adrenaline.
• pancreas — Secretes insulin and glucagon.
• testes — Secrete testosterone (in males).
• ovaries — Secrete oestrogen and progesterone (in females).

Section Through the Skin (Figure 14 (skin))

• hair erector muscle — Raises the hair to trap air for insulation.
• hair — Traps air for insulation.
• sweat pore — Opening through which sweat reaches the surface.
• temperature receptors — Detect changes in temperature.
• sensory neurone — Carries impulses from receptors.
• pressure receptor — Detects pressure on the skin.
• fat cells — Provide insulation and store energy.
• blood capillary — Vasodilation/constriction controls heat loss.
• shunt vessel — Diverts blood towards or away from the surface.
• sweat gland — Produces sweat to cool the body.
• venule / arteriole — Small vein / small artery supplying the skin.

Excretion

Human Excretory System (Figure 13.2)

• renal artery — Carries blood to the kidney to be filtered.
• renal vein — Carries filtered blood away from the kidney.
• kidney — Filters the blood and removes urea, making urine.
• ureter — Carries urine from the kidney to the bladder.
• bladder — Stores urine.
• urethra — Carries urine out of the body.
• sphincter muscle — Controls the release of urine from the bladder.

Longitudinal Section of a Kidney (Figure 13.4)

• cortex — Outer region of the kidney where filtration starts.
• medulla — Inner region of the kidney.
• nephron — Microscopic functional unit that filters blood and makes urine.
• ureter — Carries urine away to the bladder.

Reproduction

Structure of a Simple Flower (Figure 14.6)

• stigma — Sticky top of the carpel that receives pollen.
• style — Connects the stigma to the ovary.
• ovary — Contains the ovules.
• ovule — Contains the female gamete; becomes a seed.
• anther — Produces pollen grains (male gametes).
• filament — Stalk that holds up the anther.
• petal — Often coloured/scented to attract pollinators.
• sepal — Protects the flower while it is in bud.
• nectary — Produces nectar to attract insects.
• receptacle — Base of the flower to which parts attach.

Wind-Pollinated (Grass) Flower (Figure 14.12)

• anthers dangling outside — Expose pollen so wind can blow it away easily.
• large amounts of light pollen — Small and light so it is carried far by the wind.
• feathery stigma hanging outside — Large surface area to catch wind-blown pollen.

Female Reproductive Organs (Figure 15.3)

• ovary — Produces egg cells (ova) and female hormones.
• oviduct (Fallopian tube) — Carries the egg to the uterus; site of fertilisation.
• uterus wall — Muscular wall that contracts during birth.
• uterus lining (endometrium) — Thickens to receive a fertilised egg.
• cervix — Ring of muscle; the neck of the uterus.
• vagina — Receives sperm; also the birth canal.

Male Reproductive Organs (Figures 15.4 & 15.5)

• testis — Produces sperm and testosterone.
• scrotum — Holds the testes outside the body at a lower temperature.
• epididymis — Stores sperm after they are made.
• sperm duct — Carries sperm towards the urethra.
• prostate gland — Adds fluid to the sperm to make semen.
• urethra — Carries both sperm and urine (at different times).
• penis — Delivers sperm into the vagina.
• erectile tissue — Fills with blood to make the penis erect.
• bladder — Stores urine.

Fetus in the Uterus (Figure 15.15)

• placenta — Where substances are exchanged between mother and fetus.
• umbilical cord — Connects the fetus to the placenta; carries blood vessels.
• amniotic sac — Membrane enclosing the fetus.
• amniotic fluid — Cushions and protects the fetus from shock.
• muscular wall of uterus — Contracts to push the baby out during birth.
• plug of mucus in cervix — Seals the uterus and protects against infection.
• fetus — The developing baby.