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BiologyUnit 1Fall 2015

Ms. TaylorPVMHS

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Biological Theory Concept

Cell All organisms are composed of cells and new cells only come from preexisting cells

Gene Organisms contain coded information that dictates their form, function, and behavior

Evolution All living things have a common ancestor, but each is adapted to a particular way of life

Homeostasis The internal environment of an organism stays relatively constant within a range protective of life

Ecosystem Organisms are members of populations that interact with each other and with the physical environment within a particular locale

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Levels of biological organizationAtoms – smallest portions of

an element

Combine themselves with other Atoms to form Molecules

Consists of a nucleus, neutrons and protons and one or more electrons bound to the nucleus by electrical attraction

calcuttahams.com

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Levels of biological organization

Molecules – atoms combine

A molecule is formed when two or more atoms are joined together chemically harvardindependent.com

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Characteristics of Living Things

Cellular Organization:- Unicellular- Single celled organism - Multi Cellular- Organism composed of many

cells

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Characteristics of Living Things

Contain similar chemicals: 1. Water 2. Carbohydrate 3. Proteins 4. Lipids 5. Nucleic Acids

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Characteristics of Living Things

Use Energy:

ALL organisms need source of energy Heterotrophs- Can not make their own food,

need to eat Autotrophs- Produce their own food

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Characteristics of Living Things

Grow and Develop:

Organisms become larger when they grow and change to produce a more complex organism when they develop

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Characteristics of Living Things

Respond to their surroundings:

A change in an organisms surroundings causes it to react, this is called stimulus

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Characteristics of Living Things

Reproduce:

To produce offspring that are similar to the parents

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BiosphereRegions of the Earth’s crust,waters, and atmosphere inhabitedby living things

EcosystemA community plus the physical environment

CommunityInteracting populations in a particular area

PopulationOrganisms of the same speciesin a particular area

OrganismAn individual; complex individualscontain organ systems

Levels of biological organization

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THE THEORY OF

HOMEOSTASISOrganisms Are Homeostatic

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Organisms regulate their internal environment

Theory of homeostasisCells and organisms have an internal environment and that cells regulate this environment so that it stays fairly constant

Response to stimuliAbility to respond to stimuli assists the homeostatic ability of organisms

All together, daily activities are termed the behavior of the organismBehavior of an organism often assists

homeostasis

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THE THEORY OF ECOSYSTEMS

Organisms Live in Ecosystems

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The biosphere is divided into ecosystems

Theory of ecosystemsOrganisms form units in which they interact with the biotic (living) and abiotic (nonliving) components of the environment

Ecosystems are characterized by chemical cycling and energy flowBegin when plants take in solar energy and inorganic nutrients to produce food by photosynthesis

Climate largely determines where different ecosystems are found in the biosphere

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THE THEORY OF EVOLUTIONOrganisms Are Related and Adapted to

Their Environment

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The ancestry of species can be determined

Theory of evolutionOrganisms have shared characteristics because of common descent

Evolutionary treeTraces the ancestry of a group to a common ancestorTraced using molecular data, fossils record, anatomy

and physiology, and embryologyNatural selection is the mechanism that results in

adaptation to the environmentOnly species (types of organisms) evolve and not individual organisms

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bird characteristicsreptile characteristics

claws

teeth

feathers

tail with vertebrae

Archeopteryx

An evolutionary tree shows how the ancestry of Archaeopteryx can be traced to a common ancestor with crocodiles and dinosaurs.

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Crocodilians

PastTime

Present

Dinosaurs

Dinosaurs

Archaeopteryxcommon ancestor

commonancestor(reptilian)

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Prokaryotes vs. Eukaryotes Prokaryotes: molecules

surrounded by a membrane and cell wall

Eukaryotes: Organisms whose cells contain a true nucleus

ebi.ac.uk

library.thinkquest.org

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Evolutionary relationships help biologists group organisms

DomainsBacteria

ProkaryotesArchaea

ProkaryotesEukarya

Eukaryotes Protists, Plants, Fungi, and Animals

Domain Eukarya

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Protists

Paramecium, a unicellular protozoan

• Algae, protozoans,slime molds, andwater molds

• Complex single cell(sometimes filaments,colonies, or evenmulticellular)

• Absorb, photosynthesize,or ingest food

1 µm

KINGDOM: Plants

• Certain algae, mosses, ferns,conifers, and flowering plants

• Multicellular, usually withspecialized tissues,containing complex cells

• Photosynthesize food

Passiflora, passion flower, a flowering plant

KINGDOM: Fungi

Coprinus, a shaggy mane mushroom

• Molds, mushrooms, yeasts,and ringworms

• Mostly multicellular filaments withspecialized, complex cells

• Absorb food

Vulpes, a red fox

• Sponges, worms, insects,fishes, frogs, turtles,birds, and mammals

• Multicellular withspecialized tissuescontaining complex cells

• Ingest food

KINGDOM: Animals

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The Theory of Evolution

The idea that there is a “Common descent with modification”

mhhe.com

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Charles Darwin The Father of evolution

Concluded that “Natural Selection” brings about adaptations to the environment

Adaptation to various environments accounts for the diversity of life on Earth

crystalinks.com

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Natural Selection

Mutations introduce variations

Some aspect of environment (abiotic or biotic) selects which traits are more apt to be passed on to the next generation

Living things having advantageous traits and can produce more offspring than those lacking them

Rockhopper penguins have become adapted toliving in the waters of Antarctic

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Evolution from a common ancestor accounts for the characteristics of life

1. Life is organized2. Life uses materials and energy3. Life reproduces4. Life is homeostatic5. Life responds to stimuli6. Life forms ecosystems7. Life evolves

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Concepts

Scientific method helps scientists come to conclusions

5 theories (cell, gene, homeostasis, ecosystems, evolution)

All theories of biology are related

Characteristics of life

All life-forms share similar characteristics because they can trace their ancestry to a common source

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Thank you for your attention