Summer work

Chapters 1, 6 and 25

History of Life on Earth

Fig 25-UN8

Millions of years ago (mya)

1.2 bya:First multicellular eukaryotes

2.1 bya:First eukaryotes (single-celled)

3.5 billion years ago (bya):First prokaryotes (single-celled)

535–525 mya:Cambrian explosion(great increasein diversity ofanimal forms)

500 mya:Colonizationof land byfungi, plantsand animals

Pre

sen

t

500

2,00

0

1,50

0

1,00

0

3,00

0

2,50

0

3,50

0

4,00

0

Early Earth

Miller/Urey experiment: Created early earth atmosphere Produced aa

Early Earth

Protobionts: Collections abiotic materials Membrane-like structures

Ribozymes: RNA catalysts

Fig. 25-9-4

Ancestral photosyntheticeukaryote

Photosyntheticprokaryote

Mitochondrion

Plastid

Nucleus

Cytoplasm

DNAPlasma membrane

Endoplasmic reticulum

Nuclear envelope

Ancestralprokaryote

Aerobicheterotrophicprokaryote

Mitochondrion

Ancestralheterotrophiceukaryote

Prokaryotes

Stromatolites: Layers of rock Prokaryotes 3.5 billion years ago

Oxygen

Photosynthetic bacteria Cynobacteria 2.7 billion years ago

Macroevolution

Evolutionary change above a species

Evolution over a large time

Change in dominant groups

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

Fig. 25-13

SouthAmerica

Pangaea

Mil

lio

ns

of

year

s ag

o

65.5

135

Mes

ozo

ic

251

Pal

eozo

ic

Gondwana

Laurasia

Eurasia

IndiaAfrica

AntarcticaAustralia

North Americ

a

Madagascar

Cen

ozo

ic

Present

Mass extinctions

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

Mass extinction

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

Adaptive radiation

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

Biology: science of life

Properties of living things

OrderSensitivityRegulationGrowth, development,and

reproductionEnergy utilizationEvolutionary adaptation

Themes Unite Biology

The cell theoryContinuity of LifeDiversity of LifeUnity of Life

Cell theory

All living things consist of cells

All cells come from cellsProkaryoticEukaryotic

Continuity of life

Inheritance of information

DNA

Evolution

Big Idea #1 Organisms have changed over time Diversity of new forms Natural selection

Diversity of Life

DomainsBacteriaArchaeaEukarya

Kingdom ProtistaKingdom PlantaeKingdom FungiKingdom Animalia

Unity of Life

Unifying themes among all living things

DNAFlagella

The cell

Membrane

Separates living cell from its surroundings

Two layers Phospholipids & proteins

Nucleus

DNA, chromosomes Nucleolus: synthesis of rRNA Nuclear envelope: double

membrane Nuclear pores: surface of the

nucleus function like channels.

Endoplasmic Reticulum

Endomembrane system Protein & lipid synthesis Rough ER

Ribosomes: site of protein synthesis Smooth ER

Synthesis of carbohydrates and lipids

Golgi bodies

Flattened stack of membranes Collection, packaging & distribution

of molecules Proteins & lipids enter the

apparatus Modified Distributed to new location

Lysosomes

Digestive vesicles Breakdown proteins, carbohydrates,

nucleic acids and lipids Break down old organelles

Ex: mitochondria are replaced in some tissues every 10 days

Mitochondria

Tubular or sausage shaped organelles

Power house of the cell DNA to make proteins needed for

metabolism

Chloroplasts

Light energy to manufacture organic molecules

Chlorophyll give plants green color Contain DNA

Centrioles

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

microtubules

Cytoskeleton

Supports the shape of the cell Contain 3 types of fibers

Microfilaments (actin fibers) Microtubules Intermediate filaments