AP Biology Chapter 1

A View of Life

Biology - the study of life

Constantly changing Increasing quality of life Drastically changing health care New discoveries daily Technology

Themes of Biology

Evolution of life Diverse life forms are related

Transmission of information DNA, Chemical signaling

Flow of energy through living systems Energy constantly required to

maintain complex processes

Characteristics of Organisms

Cells – organisms are made of one or more cells Cell Theory:

All living organisms are composed of cells New cells arise from existing cells Cells are basic unit of structure and

function of living things Schleiden, Schwann, and Virchow

**Cell Theory Video

Characteristics of Organisms

Organisms grow and develop Biological growth - increase in the

size of cells or the number of cells Growth may be uniform or greater in

some parts than others Development - all the changes that

take place during an organism's life

Characteristics of Organisms

Metabolism - the sum of all the chemical activities of the organism Processes occur continuously in every living

organism Must be carefully regulated to maintain

homeostasis Homeostatic mechanisms are control

systems that maintain constant levels of cellular products in the organism

Example - regulation of glucose in the blood of complex animals

Heterotrophs – organism that obtains food by consuming other living organisms

Autotrophs – organism that makes its own food Photosynthesis Chemosynthesis

**Metabolism Video Clip

Characteristics of Organisms

Movement - basic property of cells Many varieties of movement

Extensions such as cilia (hairlike) and flagella (longer structures)

Animals move obviously (swim, crawl, run, fly) - have complex tissues for movement = muscles!

Even plants move toward the sun or trap insects

Characteristics of Organisms

Organisms respond to stimuli Stimuli that evoke a response in

organisms: Changes in light intensity, direction, or

color Changes in temperature, pressure, or

sound Changes in the chemical composition of

the surrounding soil, air, or water Plants respond to stimuli too!

Characteristics of Organisms

Reproduction Asexual - exact copy

of parent, ex. bacteria

Sexual - egg and sperm cells combine to form a fertilized egg, provides genetic variation

Can be internal or external fertilization

Characteristics of Organisms

Adaptations Adaptations are traits that enhance

an organism's ability to survive Every organism is a complex

collection of coordinated adaptations produced through evolutionary processes

Transmission of Information

Instructions are needed to carry out life processes

DNA - genetic material Watson and Crick, 1953 Makes up genes - the

hereditary units Used to specify

instructions for making every living organism

Transmission of Information

DNA contains the information to make all the proteins needed by an organism

Proteins determine the structure and function of cells and tissues

Cells also use proteins to communicate with one another Cell signaling *Learning to manipulate cell signaling may lead

to new discoveries in the medicine.

Chemical Transmission of Information

Hormones - molecules that function as chemical messengers that transmit information from one part of an organism to another Can signal cells to produce a protein

or other substance

Electrical Transmission of Information

Nervous Systems Electrical Impulses Neurotransmitters -

chemical compounds Ex. Transmit

message from eyes and ears to the brain

Biological Organization

Hierarchical At every level,

structure and function are coordinated

Solomon p.9

Chemical – atomsMolecule – atoms combineCell – atoms and molecules form cells (basic structure of living things)Tissue – cells working togetherOrgan – tissues organizedOrgan System – group of tissues and organsOrganism – organ systems working together

Smallest

Largest

Ecological Organization

Population – all the members of one species that live in the same geographic area at the same time

Community – the populations of organisms that inhabit a particular area and interact with one another Can be hundreds of different

organisms

Ecological Organization Ecosystem – a community together

with its nonliving environment Can vary greatly in size

Biosphere – all of Earth’s ecosystems together

Ecology – the study of how organisms relate to one another and to their environment

Evolutionary Relationships Systematics – studies evolutionary

relationships Taxonomy – the science of naming

and classifying organisms Binomial nomenclature – each

species is assigned a two-part name 1st part of name = genus 2nd part of name = specific epithet

Taxonomic Classification Remember: King Phillip Came Over For

Good Spaghetti Kingdom, Phylum, Class, Order, Family,

Genus, Specific epithet See page 11 (table 1-1)

3 domains: Archaea, Eubacteria, and Eukarya

6 kingdoms: Plant, Animal, Fungi, Protista Archaebacteria, Eubacteria

Evolution is the primary unifying concept of biology

Theory of evolution explains how populations change over time

Natural Selection – mechanism by which evolution proceeds Organisms that possess favorable

adaptations to their environment survive and pass on genes to next generation

Biology is Studied using the Scientific Method Involves a series of ordered steps and is

the framework used by scientists Scientists make careful observations,

ask critical questions, and develop hypotheses

Then, scientists make predictions, test their predictions, interpret results, and draw conclusions

See page 17 (figure 1-16)

Scientific Method

A properly designed experiment includes: a control group and experimental group Only differ with respect to the

variable being studied Must be free of bias!

Scientific Method

When a number of related hypotheses have been supported many times, scientists develop a theory A theory is a well researched and

supported scientific statement. A well established and tested theory

may be referred to as a scientific principle