Biology Unit 1 Study Guide: Organisation, Organic Biomolecules and Human Tissues

A set of 45 vocabulary flashcards covering the levels of biological organisation, organic biomolecules, cell differentiation, and the structural and functional classification of human tissues.

Atom

The smallest unit of matter; examples include carbon, hydrogen, and oxygen.

Molecule

Two or more atoms joined by chemical bonds; examples include water, glucose, and proteins.

Cell

The basic unit of life that carries out vital functions; examples include neurons and red blood cells.

Tissue

A group of cells with similar structure and function, such as muscle tissue.

Organ

Different tissues working together in a single structure, such as the heart, lungs, or liver.

Organ system

A group of organs working together, such as the digestive or nervous system.

Organism

A complete living individual, such as a human being.

Organic biomolecules

Molecules found in living beings that are characterised by a high level of carbon atoms and formed by associations of atoms joined by chemical bonds.

Carbohydrates

Biomolecules that serve as a source of energy, which can be simple (such as glucose) or complex (such as cellulose).

Glucose

A simple carbohydrate used directly by cells as an energy source.

Starch

A carbohydrate found in bread, rice, pasta, and potatoes that is broken down through digestion into smaller sugars to provide energy.

Lipids

A varied group of biomolecules that act as energy sources, structural components of membranes, and protective materials.

Phospholipids

Lipids that function as important structural components of cell membranes.

Proteins

The second most abundant component in living beings; they act as enzymes managing metabolic reactions, structural proteins providing support, and transport proteins moving substances.

Enzymes

Proteins that manage metabolic reactions, such as digestive enzymes that help break down food.

Haemoglobin

A transport protein that transports oxygen in the blood.

Nucleic acids

Biomolecules (DNA and RNA) that record and help use genetic information across generations and for cell functions.

DNA

A nucleic acid in cells that carries inherited genetic information from biological parents.

RNA

A nucleic acid that helps cells use inherited genetic information to make proteins.

Cell differentiation

The process in which cells become specialised, involving changes in cell shape and functionality.

Gametes

Specialised reproductive cells (ova and sperm cells) that unite during fertilisation.

Zygote

The single cell formed after sexual reproduction when two gametes fuse, which subsequently divides to produce stem cells.

Stem cells

Cells produced by the division of the zygote that subsequently undergo differentiation to become specialised cells.

Adipocytes

Specialised fat cells that store energy as fat.

Epithelial tissue

A primary tissue group responsible for protection, covering, lining, and secretion, characterized by tightly packed cells forming continuous sheets or layers with very little space between them.

Covering and lining epithelium

Epithelial tissue that covers the exterior body and lines internal organs and spaces, separating internal structures from the external environment.

Glandular epithelium

Epithelial tissue specialised in secreting substances, which may appear as scattered cells, clusters, or rounded secretory structures.

Connective tissue

A major tissue group that supports and connects organs and tissues, defined by cells surrounded by fibres and an intercellular matrix.

Reticular tissue

A type of connective tissue featuring fine network-like supporting material that forms a supporting network between organs.

Adipose tissue

A connective tissue containing large, rounded, or empty-looking adipocytes with nuclei often pushed to the edge, specialized for storing fat as an energy reserve.

Supportive connective tissue

Connective tissue that connects and supports other tissues (such as tendons and ligaments), identified by fibres arranged in bundles with relatively few visible cells.

Cartilaginous tissue

A connective tissue providing firm but flexible support and covering joints to prevent wearing, recognizable by rounded chondrocytes sitting in spaces within a smooth matrix.

Chondrocytes

Rounded cells that reside in distinct spaces (lacunae) within the smooth matrix of cartilaginous tissue.

Osseous tissue

Hard connective tissue containing abundant calcium salts that supports and protects, featuring a dense matrix that often displays circular or concentric patterns.

Blood tissue

A connective tissue consisting of a liquid matrix (plasma) with numerous small cells (red and white blood cells) and platelets floating in it.

Plasma

The liquid intercellular matrix of blood tissue in which blood cells and platelets are suspended.

Immune / lymphoid tissue

A tissue involved in defence against pathogens, identified under microscopy by dense groups of many small, dark-staining lymphocytes packed closely together.

Lymphocytes

Small, dark-staining cells that are densely packed together in immune / lymphoid tissue to defend against pathogens.

Muscle tissue

A primary tissue group composed of elongated cells gathered into fibres that contract and relax to produce movement.

Skeletal striated muscle

Voluntary muscle tissue characterised by long parallel fibres with visible stripes (striations) and several nuclei located near the edges.

Cardiac striated muscle

Involuntary striated muscle tissue of the heart, featuring branching fibres with striations and usually one centrally located nucleus.

Smooth muscle

Involuntary muscle tissue found in internal organs like the gut and stomach, composed of spindle-shaped elongated cells without visible striations.

Nervous tissue

A primary tissue group that receives, integrates, and transmits information to produce a coordinated response to the environment.

Neurons

Specialised cells of nervous tissue that receive and transmit information, consisting of a cell body with branching dendrites and a long axon.

Glial cells

Smaller supporting cells in nervous tissue that surround neurons and provide them with nutrients, oxygen, and defence.