Summer work Chapters 1, 6 and 25

Biology: science of life

Properties of living things  Order  Sensitivity  Regulation  Growth, development,and reproduction  Energy utilization  Evolutionary adaptation

Themes Unite Biology  The cell theory  Continuity of Life  Diversity of Life  Unity of Life

Cell theory  All living things consist of cells  All cells come from cells  Prokaryotic  Eukaryotic

Continuity of life  Inheritance of information  DNA

Evolution  Big Idea #1  Organisms change over time  Diversity of new forms  Natural selection

Macroevolution  Evolutionary change above a species  Evolution over a large time

Unity of Life  Unifying themes among all living things  DNA  Flagella

Diversity of Life  Domains Bacteria Archaea Eukarya  Kingdom Protista  Kingdom Plantae  Kingdom Fungi  Kingdom Animalia

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 increase in diversity of animal forms) 500 mya: Colonization of land by fungi, plants and animals Present 500 2,000 1,500 1,000 3,000 2,500 3,500 4,000

Early Earth  Miller/Urey experiment:  Created early earth atmosphere  Produced aa  Protobionts:  Collections of abiotic materials  Ribozymes:  RNA enzymes

Prokaryotes  Stromatolites:  Layers of rock  Prokaryotes  3.5 billion years ago

Oxygen  Photosynthetic bacteria  Cynobacteria  2.7 billion years ago

Fig Ancestral photosynthetic eukaryote Photosynthetic prokaryote Mitochondrion Plastid Nucleus Cytoplasm DNA Plasma membrane Endoplasmic reticulum Nuclear envelope Ancestral prokaryote Aerobic heterotrophic prokaryote Mitochondrion Ancestral heterotrophic eukaryote

Change in dominant groups  1. land movement  2. mass extinctions  3. adaptive radiation

Fig South America Pangaea Millions of years ago Mesozoic 251 Paleozoic Gondwana Laurasia Eurasia India Africa Antarctica Australia North America Madagascar Cenozoic 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

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  Rough ER:  Ribosomes  Site of protein synthesis  Smooth ER:  Synthesis of carbohydrates &lipids

Golgi bodies  Flattened stack of membranes  Collection, packaging & distribution of molecules  Proteins & lipids enter apparatus  Modified  Distributed to new location

Lysosomes  Digestive vesicles  Breakdown proteins, carbohydrates, nucleic acids & 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  Own DNA  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