Important Terms/Concepts BIO

Question 1

Mechanical and Chemical Digestion

Answer 1

Definition: Mechanical digestion involves the physical breakdown of food into smaller particles, while chemical digestion involves the breakdown of complex molecules into simpler ones by enzymes.

Understanding: Both processes are crucial for nutrient absorption. Mechanical digestion increases the surface area for chemical digestion.

Applications: Chewing (mechanical) and enzyme action in the stomach and small intestine (chemical). Chemical digestion also occurs in the mouth with an enzyme called amylase beginning to break down carbohydrates.

Question 2

Fast and Slow Twitch Muscle Fibres

Answer 2

Definition: Muscle fibres with different contraction speeds. Slow twitch fibres contract slowly and are fatigue-resistant, while fast twitch fibres contract quickly and fatigue faster.

Understanding: Adaptations for endurance (slow twitch) and strength/power (fast twitch).

Applications: Marathon running (slow twitch fibres that work longer) and weightlifting (fast twitch fibres that are explosive).

Question 3

Leukocyte

Answer 3

Definition: White blood cells are involved in the immune system, defending against pathogens.

Understanding: Different types like neutrophils and lymphocytes have specific roles in immunity. It makes up <1% of the blood.

Applications: Fighting infections, immune response.

Question 4

Erythrocyte

Answer 4

Definition: Red blood cells responsible for oxygen transport, containing the protein haemoglobin (containing iron and giving blood its red colour).

Understanding: Lack of a nucleus for increased oxygen-carrying capacity. It makes up 45% of the blood.

Applications: Oxygen transport in the bloodstream.

Question 5

Platelet

Answer 5

Definition: Small cell fragments involved in blood clotting.

Understanding: Released from megakaryocytes, initiates clotting by forming a plug. It makes up <1% of the blood.

Applications: Preventing excessive bleeding through clot formation.

Question 6

Diffusion

Answer 6

Definition: Passive movement of particles from an area of high concentration to a low concentration.

Understanding: Driven by concentration gradients, essential for nutrient exchange.

Applications: Oxygen and carbon dioxide exchange in the lungs.

Question 7

Osmosis

Answer 7

Definition: Movement of water across a selectively permeable membrane from an area of low solute concentration to high solute concentration.

Understanding: Critical for maintaining water balance in cells.

Applications: Regulating water content in plants.

Question 8

Cuticle

Answer 8

Definition: Waxy, protective layer covering the epidermis of leaves and stems in plants.

Understanding: Reduces water loss, and protects against pathogens.

Applications: Adaptation to arid environments, preventing dehydration for plants like cacti.

Question 9

Chromatin

Answer 9

Definition: Complex of DNA and proteins in the nucleus of eukaryotic cells.

Understanding: Condenses into chromosomes during cell division.

Applications: Gene expression and regulation.

Question 10

Chromatid

Answer 10

Definition: One of the two identical halves of a replicated chromosome.

Understanding: Separates during cell division.

Applications: Ensures genetic continuity in daughter cells.

Question 11

Chromosome

Answer 11

Definition: Thread-like structure composed of DNA and proteins, carrying genetic information.

Understanding: Contains genes, the units of heredity.

Applications: Inheritance of traits from parent to offspring.

Question 12

Centromere

Answer 12

Definition: Region of a chromosome where sister chromatids are joined.

Understanding: Essential for proper chromosome segregation during cell division.

Applications: Ensures accurate distribution of genetic material.

Question 13

Haemoglobin

Answer 13

Definition: Protein in red blood cells that binds and transports oxygen.

Understanding: Iron-containing, gives blood its red colour.

Applications: Oxygen transport in the bloodstream.

Question 14

Tendon

Answer 14

Definition: Fibrous connective tissue that attaches muscle to bone.

Understanding: Transmits force from muscle to bone for movement.

Applications: Muscle contraction and movement.

Question 15

Benign Tumour

Answer 15

Definition: Non-cancerous mass of cells that does not invade nearby tissues.

Understanding: Typically slow-growing and encapsulated.

Applications: Often not harmful but may cause issues if pressing on nearby structures.

Question 16

Malignant Tumour

Answer 16

Definition: Cancerous mass of cells capable of invading surrounding tissues.

Understanding: Can spread to other parts of the body (metastasis).

Applications: Cancer development and progression.

Question 17

Mutation

Answer 17

Definition: Permanent change in the DNA sequence of a gene.

Understanding: Source of genetic diversity and can lead to diseases or beneficial traits.

Applications: Evolution and adaptation.

Question 18

Metastasis

Answer 18

Definition: Spread of cancer cells from the primary site to other parts of the body.

Understanding: Occurs through the bloodstream or lymphatic system.

Applications: Cancer progression and treatment planning.

Question 19

Ligament

Answer 19

Definition: Fibrous connective tissue that connects bone to bone.

Understanding: Provides joint stability and limits excessive movement.

Applications: Joint support and flexibility.

Question 20

Cartilage

Answer 20

Definition: Flexible connective tissue found in joints and other body structures.

Understanding: Acts as a cushion and reduces friction between bones.

Applications: Joint flexibility and support.

Question 21

Myelin

Answer 21

Definition: Fatty substance that wraps around nerve fibres, insulating and speeding up nerve impulse transmission.

Understanding: Produced by glial cells.

Applications: Enhances electrical conductivity in the nervous system.

Question 22

Stem Cell

Answer 22

Definition: Undifferentiated cells with the potential to become various cell types.

Understanding: Can divide into identical stem cells (self-renewal) or differentiate into specialised cells.

Applications: Regenerative medicine, tissue repair.

Question 23

Phloem

Answer 23

Definition: Vascular tissue in plants responsible for the transport of sugars and other organic nutrients.

Understanding: Moves materials from sources (leaves) to sinks (roots, fruits).

Applications: Nutrient distribution in plants.

Question 24

Xylem

Answer 24

Definition: Vascular tissue in plants responsible for the transport of water and minerals.

Understanding: Transports water from roots to other parts of the plant.

Applications: Water uptake and support in plants. It ensures that the cells are receiving the water and minerals they need to survive.

Question 25

Stomata

Answer 25

Definition: Small pores on the surface of leaves and stems in plants that regulate gas exchange and water loss.

Understanding: Guard cells control opening and closing.

Applications: Gas exchange and water regulation in plants.

Question 26

Palisade/Spongy Mesophyll

Answer 26

Definition: Tissues in plant leaves involved in photosynthesis. Palisade mesophyll is tightly packed with chloroplasts, while spongy mesophyll allows for gas exchange.

Understanding: Key for capturing sunlight and exchanging gases.

Applications: Photosynthesis and nutrient assimilation in plants.

Question 27

Shoot/Root System

Answer 27

Definition: The shoot system includes stems, leaves, and flowers, while the root system comprises roots.

Understanding: Shoots are involved in photosynthesis, roots in water and nutrient absorption.

Applications: Plant structure and function.

Question 28

Photosynthesis

Answer 28

Definition: Process by which plants and some bacteria convert light energy into chemical energy (glucose).

Understanding: Occurs in chloroplasts, and involves light-dependent and light-independent reactions.

Applications: Basis of energy flow in ecosystems.

Question 29

Peristalsis

Answer 29

Definition: Wave-like muscle contractions that propel food through the digestive tract.

Understanding: Facilitates the movement of food from the mouth to the stomach.

Applications: Digestive system function.

Question 30

Cilia

Answer 30

Definition: Hair-like structures on the surface of some cells, involved in movement or the transport of substances.

Understanding: Beat in coordinated patterns for movement or move substances along the cell surface.

Applications: Respiratory system (moving mucus), reproductive system (egg transport).

Question 31

Mucous

Answer 31

Definition: Slimy substance produced by mucous membranes, providing protection and lubrication.

Understanding: Traps and removes particles, and protects against pathogens.

Applications: Respiratory and digestive system protection.