Date:22 March 2024

Topic/section: Diversity of life

Colour Coding:

Important

Confused/unclear

3 domains of life

-Plants

-animals

-Neither: fungi, protest, bacteria

The cell

Eukaryotic: Multicellular organisms (plant and animal)

Prokaryotic: unicellular (bacteria and amoeba)

Animal vs Plant Cell

-Shapes are different

-Plant has chloroplast

Classification of animals

Vertebrates: have a backbones

Invertbrates: no backbones

Classification regimes

-Linnaean Classification: human {Most popular}

-Evolutionary classification

Types of classifications:

-species

-familia

-animalia

Linnaean:

species grouped based on shared similarities of organisms

species= genus

Genera= family

families= order

order= class

phyla= kingdom

kingdom= domain

Humans

-Genus: homo

-Hominidae family

-order: primates

-class: mammalia

-Species: sapiens

-Phylum: chordata

-domain: Eurkarya

Evolutionary classification

Groups based on their evolutionary relationships and places birds among reptiles

What is a clade

• a group of species that includes an ancestor and all its descendants

• Linnaean kingdom of animalia is a clade

• Not all linnaean groups are clades

• linnaean class reptilia are not clade

Animals

• are mutlicellular heterotrophic eukaryotes

• reproduce sexually and are diploid during most of their life cycles

3 domains of life

-Life is:

• Bacteria

• Archea

• Eukarya

Bacteria and Archea consist of prokaryotic organisms, organisms whose cells do not have a nucleus

Eukarya include all living things whose cells have a nucleus

The eukarya domain is further divided into:

-Protists

-plants

-fungi

-animals

Key characteristics:

Protists kingdom is problematic because because it includes all eukaryotes that arnt plants, animals or fungi- it is a mix of species that dont rep a clade.

Amoebas, kelp and diatoms are all protists, although they have little in common besides the fact that they are eukaryotes

until a more accurate classification emerges however we are stuck with the term protists

Bacteria

• live on human bodies and old fossils

• prokaryotes that are autotrophs ( they make their own food by photosynthesis)

• Chemoautotrophs: make food using chemical energy

• heterotrophs: obtain food from organic matter

• most are unicellular and come in various shapes: rod, spirals, spheres

• many move using flagella

• reproduce asexually

• need favourable conditions and can reproduce every 20min

why is bacteria important

-single celled bacteria:

• decomposing of organic matter

• fixation of nitrogen for it to be used by living organisms

• to make cheese and yogurt

• produce human insulin -medically

• build up of carbon dioxide

Archaea (our-kee-uh)

-Extremophiles: Able to adapt to environments

-Also found in digestive tracts

-produce methance as a waste product

Protists:

-reproduce asexually or sexually

-many are autotrophs

-Eukaryotes

-autotrops and or heterotrophs

single celled or multicelled

-great part of marine food chains

Diatoms

-Single celled protists

-shells made from silica

-photosynthesis

used in human made products e.g toothpaste

found floating in the ocean

Dinoflagellates

-single celled marine protists

-autotrophs or heterotrophes

-produce red tides

-some red tides are toxic

-shellfish eat dinoflagellates and become contaminated and poisonous

seaweed are protists

• kelp

• red algae

• green algae

diseases caused by protists

• malaria

• african sleeping sickness

• amoeba dysentery

What is ecology

• The scientific study of interactions between different organisms and between organisms and their environment

Ecosystem:

• structural and functional unit of ecology where the living organisms interact with each other

• characterised by the organisation of both biotic and abiotic

• Biotic factors are living things within an ecosystem; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere.

• includes climatic conditions

• distribution of energy

• an open system

Biotic components

• all living components in an ecosystems

  • autotrophs, heterotrophs and saprotrophs (decomposers)

    Producers

    • all autotrophs e.g plants

From Kai:

• Functions of an Ecosystem:

  1. Primary Production: Conversion of sunlight into energy by plants.

  2. Nutrient Cycling: Recycling of nutrients through biotic and abiotic components.

  3. Energy Flow: Transfer of energy through trophic levels.

  4. Habitat Provision: Providing living space for organisms.

  5. Climate Regulation: Influence on local and global climate.

  6. Pollution Control: Natural filtration and breakdown of pollutants.

  7. Biodiversity Support: Maintenance of diverse species interactions.

  8. Ecosystem Services: Benefits to humans like food, water, and air purification.