Summer work

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Summer work

• Chapters 1, 6 and 25

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History of Life on Earth
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Fig 25-UN8
1.2 bya First multicellular eukaryotes
535525 mya Cambrian explosion (great
increase in diversity of animal forms)
500 mya Colonization of land by fungi,
plants and animals
2.1 bya First eukaryotes (single-celled)
3.5 billion years ago (bya) First prokaryotes
(single-celled)
500
1,000
1,500
2,000
3,000
2,500
3,500
4,000
Present
Millions of years ago (mya)
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Early Earth

• Miller/Urey experiment
• Created early earth atmosphere
• Produced aa

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Early Earth

• Protobionts
• Collections abiotic materials
• Membrane-like structures
• Ribozymes
• RNA catalysts

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Fig. 25-9-4
Cytoplasm
Plasma membrane
DNA
Ancestral prokaryote
Endoplasmic reticulum
Nucleus
Nuclear envelope
Aerobic heterotrophic prokaryote
Photosynthetic prokaryote
Mitochondrion
Mitochondrion
Ancestral heterotrophic eukaryote
Plastid
Ancestral photosynthetic eukaryote
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Prokaryotes

• Stromatolites
• Layers of rock
• Prokaryotes
• 3.5 billion years ago

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Oxygen

• Photosynthetic bacteria
• Cynobacteria
• 2.7 billion years ago

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Change in dominant groups

• 1. land movement
• 2. mass extinctions
• 3. adaptive radiation

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Fig. 25-13
Present
Cenozoic
Eurasia
North America
Africa
65.5
India
South America
Australia
Madagascar
Antarctica
Laurasia
135
Mesozoic
Gondwana
Millions of years ago
Pangaea
251
Paleozoic
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Mass extinctions

• 5 over past 500 mya
• Permian (251 mya)
• Eliminated 75 marine life
• Massive volcano eruptions
• Cretaceous (65.5 mya)
• Dinosaurs
• ?? asteroid

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Mass extinction

• Decrease diversity
• Change ecological communities
• Allows some species to thrive
• Humans evolved

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Macroevolution

• Evolutionary change above a species
• Evolution on a grand scale
• Species in a new habitat
• Mass extinctions

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Adaptive radiation

• Organisms form new species
• Evolve to fill new communities
• Occurred after extinctions
• Now vacant niches
• Mammals
• Hawaii

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Biology science of life
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Properties of living things

• Order
• Sensitivity
• Regulation
• Growth, development,and reproduction
• Energy utilization
• Evolutionary adaptation

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Themes Unite Biology

• The cell theory
• Continuity of Life
• Diversity of Life
• Unity of Life

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Cell theory

• All living things consist of cells
• All cells come from cells
• Prokaryotic
• Eukaryotic

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Continuity of life

• Inheritance of information
• DNA

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Evolution

• Core theme
• Organisms have changed over time
• Diversity of new forms
• Natural selection

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Diversity of Life

• Domains
• Bacteria
• Archaea
• Eukarya
• Kingdom Protista
• Kingdom Plantae
• Kingdom Fungi
• Kingdom Animalia

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Unity of Life

• Unifying themes among all living things
• DNA
• Flagella

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The cell
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Membrane

• Separates living cell from its surroundings
• Two layers
• Phospholipids proteins

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Nucleus

• DNA, chromosomes
• Nucleolus synthesis of rRNA
• Nuclear envelope double membrane
• Nuclear pores surface of the nucleus function
  like channels.

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Endoplasmic Reticulum

• Endomembrane system
• Protein lipid synthesis
• Rough ER
• Ribosomes site of protein synthesis
• Smooth ER
• Synthesis of carbohydrates and lipids

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Golgi bodies

• Flattened stack of membranes
• Collection, packaging distribution of molecules
• Proteins lipids enter the apparatus
• Modified
• Distributed to new location

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Lysosomes

• Digestive vesicles
• Breakdown proteins, carbohydrates, nucleic acids
  and lipids
• Break down old organelles
• Ex mitochondria are replaced in some tissues
  every 10 days

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Mitochondria

• Tubular or sausage shaped organelles
• Power house of the cell
• DNA to make proteins needed for metabolism

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Chloroplasts

• Light energy to manufacture organic molecules
• Chlorophyll give plants green color
• Contain DNA

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Centrioles

• Barrel shaped organelles
• Right angles near the nucleus
• Help assemble the cells microtubules

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Cytoskeleton

• Supports the shape of the cell
• Contain 3 types of fibers
• Microfilaments (actin fibers)
• Microtubules
• Intermediate filaments