Biologie: Selstruktuur en Funksie

Cell Structure and Function

• Cell Theory: All living organisms are composed of cells; the cell is the basic unit of life; all cells arise from pre-existing cells.
• Types of Cells:
  • Prokaryotic Cells: No nucleus or membrane-bound organelles (e.g., bacteria).
  • Eukaryotic Cells: Have a nucleus and organelles (e.g., plant and animal cells).

Genetics

• DNA: Carries genetic information, composed of nucleotides (A, T, C, G).
• Gene: A segment of DNA coding for a protein.
• Chromosomes: Structures made of DNA and proteins, humans have 46 (23 pairs).
• Mendelian Genetics: Study of inheritance patterns (e.g., dominant and recessive traits).

Evolution

• Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.
• Speciation: Formation of new species through evolution.
• Common Descent: All living organisms share a common ancestor.

Ecology

• Ecosystem: A community of living organisms interacting with their environment.
• Biodiversity: Variety of life in an ecosystem; crucial for resilience and stability.
• Food Chains and Webs: Energy flow from producers (plants) to various levels of consumers (herbivores, carnivores).

Human Biology

• Organ Systems: Groups of organs working together (e.g., respiratory, circulatory, nervous systems).
• Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).
• Immune System: Body's defense against pathogens; includes white blood cells and antibodies.

Biochemistry

• Macromolecules: Four main types - carbohydrates (energy storage), lipids (fats and oils), proteins (structural and functional roles), nucleic acids (DNA and RNA).
• Enzymes: Biological catalysts that speed up chemical reactions; affected by temperature and pH.

Plant Biology

• Photosynthesis: Process by which plants convert light energy into chemical energy (glucose) using chlorophyll.
• Tropisms: Growth responses to environmental stimuli (e.g., phototropism - light, gravitropism - gravity).

Microbiology

• Bacteria: Single-celled organisms; can be beneficial (gut bacteria) or harmful (pathogens).
• Viruses: Non-living entities that require a host to replicate; can cause diseases.

Biotechnology

• Genetic Modification: Alteration of an organism's DNA to achieve desired traits.
• CRISPR: A genome editing tool that allows for precise changes in DNA.

Selstruktuur en Funksie

• Al lewende organismes is opgebou uit selle.
• Die sel is die basiese eenheid van lewe.
• Alle selle ontstaan uit bestaande selle.
• Prokariotiese selle: Het geen kern of membraan-gebonde organelle nie, soos bakterieë.
• Eukariotiese selle: Het 'n kern en organelle, soos plant- en diers selle.

Genetika

• DNA dra genetiese inligting en bestaan uit nukleotiede (A, T, C, G).
• 'n Gen is 'n segment van DNA wat vir 'n proteïen kodeer.
• Chromosome is strukture gemaak van DNA en proteïene, mense het 46 (23 pare).
• Mendeliese Genetika bestudeer oorerflike patroon (bv. dominante en resessiewe eienskappe).

Evolusie

• Natuurlike seleksie is 'n meganisme van evolusie waar organismes beter aangepas by hul omgewing geneig is om te oorleef en voort te plant.
• Spesiasie is die vorming van nuwe spesies deur evolusie.
• Gemeenskaplike afkoms beteken dat alle lewende organismes 'n gemeenskaplike voorouer deel.

Ekologie

• 'n Ekosisteem is 'n gemeenskap van lewende organismes wat met hul omgewing wisselwerk.
• Biodiversiteit is die verskeidenheid van lewe in 'n ekosisteem, wat noodsaaklik is vir weerbaarheid en stabiliteit.
• Voedselkettings en -webbe verteenwoordig die energievloei van produsente (plante) na verskillende vlakke van verbruikers (herbivore, karnivore).

Menslike Biologie

• Organstelsels is groepe organe wat saamwerk (bv. respiratoriese, sirkulasiestelsel, senuweestelsel).
• Homeostase is die handhawing van stabiele interne toestande (bv. temperatuur, pH).
• Die immuunstelsel is die liggaam se verdediging teen patogene, dit sluit witbloedselle en antiliggame in.

Biochemie

• Makromolekule: Vier hooftipes - koolhidrate (energiebergings), lipides (vette en olies), proteïene (strukturele en funksionele rolle), nukleïensure (DNA en RNA).
• Ensieme is biologiese katalisators wat chemiese reaksies versnel. Hulle word beïnvloed deur temperatuur en pH.

Plantkunde

• Fotosintese is die proses waardeur plante ligenergie omskakel in chemiese energie (glukose) met behulp van chlorofil.
• Tropismes is groeirespons op omgewingstimuli (bv. fototropisme - lig, gravitropisme - swaartekrag).

Mikrobiologie

• Bakterieë is enkelsellige organismes wat voordelig (dermbakterieë) of skadelik (patogene) kan wees.
• Virus is nie-lewende entiteite wat 'n gasheer benodig om te repliseer, dit kan siektes veroorsaak.

Biotechnologie

• Genetiese Modifikasie is die verandering van 'n organismes 'n DNA om gewenste eienskappe te bereik.
• CRISPR is 'n genoomredaksie instrument wat presiese veranderinge in DNA moontlik maak.