Bio I

Biology:

Biolife

Logy Gr. “Logos” = study of

Characteristics of life

1. Cellular - Made up of cells

2. Able to Reproduce - The ability to perpetuate

3. Genetic code

DNA :Adenine, Guanine, Cytosine, Thymine

RNA: Adenine, Guanine, Cytosine, Uracil

deoxyribonucleic acidribonucleic acid

DNA – carrier

RNA – messenger

DNA is self-replicating which is efficient for survival

Nucleic acids ~ nucleotides

1. 5C simple sugar2. N -bases3. Phosphate PO4

DNA and RNA

Central / Molecular Dogma

4.Grow and Develop

Grow – increase size and/or number of cells

Develop –changes from early stages to the mature stages

5. Metabolism – sum total of all chemical reactions

6. Exhibit to Irritability – respond to environment

7. Undergo homeostasis – can maintain internal balance

8. Adapt and evolve – suited to live in its particular environment

Themes that unify Biology

1. Cell

Every organism’s basic units of structure and function

Two main types:

Prokaryotic ( bacteria, archea)

Eukaryotic (Protists, plants, fungi, animals)

2. Heritable information

The continuity of life depends on the inheritance of biological information in the form of DNA molecules

Genetic information is encoded in the nucleotide sequences of DNA

3. Emergent properties

The world has a hierarchical organization

Emergent properties – the result of interactions among components at the lower level.

4. Regulation

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Feed back mechanisms regulate biological systems.

Unity and diversity

Biologists divided life into 3 domains:

› Bacteria , Archea , Eukarya

Unity universal genetic code

The more related, the more characteristics they share

Evolution

Darwinian theory of natural selection

Adaptation of populations are through differential reproductive success of varying individuals

Scientific inquiry

The process of science includes observation-based discovery and the testing of explanations through hypothesis based inquiry.

Levels of organization

1. Atom

2. Molecule

3. Tissue

4. Organ

5. Organ system

6. Organism

7. Population

8. Community

9. Ecosystems

10. Biome

11. Biosphere

Ecology - Study of interaction among organisms in their environment

Relationships

Biotic – biotic

Abiotic – abiotic

Abiotic - biotic

Biosphere

Portions of the planet in which life exists

Atmosphere Hydrosphere Lithosphere

Self-contained Patchy

Biomes

Group of ecosystems that have the same climate and similar dominant communities

Habitat – area where organisms live

Niche – role in the area

Ecological Niche

Each organism has a specific role that contributes to the ecosystem

Ecological succession

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the observed process of change in the species structure of an ecological community over time.

The most efficient and most adapted organisms become the most adundant species

Occurs when there are drastic and sudden changes in the environment

Pioneer community- the organisms present that are most suited for this environment

Pioneer species

Climax community – organisms that are most suited for the present environment after the change

Dominant species

Competitive exclusion principle

Fundamental rule in ecology stating that no two organisms can occupy the exact niche for an indefinite time

Perinial – long life

Annual – yearly

Biannual – every two years

Flow of energy

This the factor that controls what kind of organisms live in an ecosystem

Determines the max number of organisms in an ecosystem

Producers – produces energy storing molecules

Consumers – consumes plants and obtains their energy

Decomposers – returns organic molecules to the ground

Scavengers – consumes carcasses

Primary energy source

Photosynthetic organisms: plants, algae, bacteria

Primary productivity – the rate at which organic material is produced.

Primary productivity determines the amount of energy available in the ecosystem

Trophic levels

Feeding positions in a food chain

These are represented in: food chains, food webs, and ecological pyramids.

Food chains – sequence of food and energy transfer.

Producer consumer decomposer

Food webs – food chains that intersect and link to each other

Ecological pyramids:

Number pyramid

Biomass pyramid

Energy pyramid

Population dynamics

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Referred to as how a number of individuals change over time

Important for the conservation of endangered species and management of life

Exponential growth is unrealistic Everything has a limit

Carrying capacity- population size that the environment can sustain for a long period of time.

Important characteristics of a population

1. Geographic distribution / range

2. Population density

3. Population dispersion

4. Uniformity

5. Random clustering

Factors that limit population size

1. Natality

2. Mortality

3. Number of individuals entering or leaving an ecosystem

Limiting factors

Density-dependent

› Competition

› Predation

› Parasitism

› Disease

Density-independent

› Unusual weather

› Natural disasters

› Season cycles

› Human activities

Abiotic and biotic factors that limit aquatic biomes

Water chemistry Temperature Depth of water

o Light penetrationo Turbidityo O2 contento Wind action, water current,

microbial action Water pressure Salinity of aquatic biomes Biological Oxygen Demand Eutrophication Turnover / upwelling Early theories on Evolution

Historical development

Carolus Linnaeus – Nested Hierarchies, Order of Nature. Classified humans among primates

Plato – idealism / essentialism. Its attributes are essentially determined and made.

Aristotle – Scala Naturae: Organisms arrange in increasing complexity

Judeo Christian culture – Creationism

“ad majorem dei gloriam”natural theology

Systema Naturae - KPCOFGS

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Binomial system of Nomenclature

Genus species

Thomas Malthus – ecology of human popuations

Jean Baptiste Lamarck – Naturalist

Philosophie Zoologique:Desire to change, use and disuse, passing of acquired traits

Georges Cuvier – catastrophism, extinctions

Charles Lyell – uniformitarianism

James hutton – Graudualism

Profound change is the cumulative product of slow but continuous process

George Mendell – father of modern genetics

discrete genes are inherited

Charles Darwin – naturalist

Theory of natural selection

Alfred Russel Wallace – theory of natural selection

Modern Theories

Francis Crick & James Watson – DNA

Understood mutations arrive to evolution

Rosalind Frank – x-ray crytallography

Structure is correlated with function

Further explanation

Malthusian Dilemma

Thomas Malthus believed that the human population would eventually grow larger than the ability of the environment to sustain it.

Natural vs. Artificial Selection

Natural – longer and random

Artificial – faster and has goals

Types of biomes

Desert - Little water, Extreme temperature changes, Hot and Dry, Difficult to adapt

Includes: Hot and Dry, Semiarid, Coastal, and Cold deserts

Forests - Dominated by trees and plants, Diverse in terms of kinds of species

Includes: Tropical, Decidiuous, and Taiga

Freshwater - Has water that has a salt level < 1%, A lot of plants and animals, Source of drinking waterIncludes: Ponds, lakes, Streams, Rivers and Wetlands

Grassland - Filled with grasses, Length of grasses depend on amount of rainfallMarine-  covers more of the Earth’s surface than any other – about 70%, provides most of the rainwater

Tundra - Cold climate, Remains wet because of the cold temp that delays evaporation

Finnish: Tunturi- treeless hill

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