IB Bio Review

Cell Theory

Cell Theory

States that all living organisms are composed of cells, the basic unit of life.

Characteristics of Life

Include growth, reproduction, response to stimuli, metabolism, and organization.

Prokaryotic Cells

Lack a nucleus and membrane-bound organelles.

Eukaryotic Cells

Have a nucleus and membrane-bound organelles.

Endosymbiotic Theory

Suggests mitochondria and chloroplasts were once free-living prokaryotes engulfed by larger cells.

Membrane Structure

Composed of phospholipids, integral proteins, peripheral proteins, and glycoproteins.

Transport Mechanisms

Include diffusion, osmosis, and active transport.

Endocytosis and Exocytosis

Processes for transporting large molecules into and out of cells.

Tonicity

Maintained through hypotonic, hypertonic, and isotonic solutions.

Macromolecules

Monomers are single units, while polymers are chains of monomers.

Hydrolysis

Breaks polymers into monomers; condensation forms polymers from monomers.

Enzymes

Biological catalysts with specific active sites for substrates.

Enzyme Inhibition

Can be competitive or non-competitive, affecting enzyme function.

Carbohydrates

Include monosaccharides, disaccharides, and polysaccharides.

Lipids

Consist of fatty acids, triglycerides, phospholipids, and steroids.

Proteins

Made up of amino acids and have diverse functions.

Nucleic Acids

Crucial for genetic information, including DNA and RNA.

Genes

Units of heredity on chromosomes, composed of nucleotides.

DNA Replication

Semi-conservative process involving DNA polymerases and enzymes.

Cell Cycle

Consists of interphase, mitosis, and cytokinesis, regulated by cyclins.

Meiosis

Leads to genetic variation through processes like crossing over and independent assortment.

Inheritance Patterns

Include incomplete dominance and sex-linked traits affecting phenotypes.

Natural Selection

Drives evolution, leading to adaptations like antibiotic resistance.

Autotrophs

Produce their own food; heterotrophs rely on others.

Evolution

Involves natural selection, adaptations, and speciation.

Cladistics

Classifies organisms based on evolutionary relationships.

Speciation

Can occur through sympatric or allopatric mechanisms.