210 likes | 403 Views
Chapter 1. The Science of Life. The Study of Life. Biology: the study of living things Some Fields of Biology: entomology (insects) parasitology (parasites) microbiology (bacteria)
E N D
Chapter 1 The Science of Life
The Study of Life • Biology: the study of living things • Some Fields of Biology: entomology (insects) parasitology (parasites) microbiology (bacteria) ornithology (birds) herpetology (reptiles)
Six Major Themes of Biology • Cell structure and function • Stability and homeostasis • Reproduction and inheritance • Evolution • Interdependence of organisms • Matter, energy, and organization
Cells are the basic unit of life All organisms are made of and develop from cells Cell Structure and Function
Organisms composed of only one cell Examples: bacteria and protists Unicellular Organisms
Organisms composed of more than one cell May be highly complex Examples: plants and animals Multicellular organisms
Facts about cells: • Cells are highly organized • Contain specialized structures • There are many different kinds of cells • Contain genetic material
Differentiation • In multicellular organisms, cells become different as they grow and develop • After fertilization, cells divide and will eventually become specialized
Living things maintain stable internal conditions Examples: body temperature, water content, electrolytes Stability and Homeostasis
Reproduction and Inheritance • Organisms transmit hereditary information to their offspring • DNA (deoxyribonucleic acid) • Gene: a short segment of DNA that contains instructions for a single trait
Production of offspring from the combination of genetic material from two parent organisms Example: sperm + egg = zygote Sexual Reproduction
Doesn’t require two different organisms One cell gives rise to two cells Example: binary fission in bacteria and protists Asexual Reproduction
Evolution • Evolution= a genetic change in a population over a long period of time • Natural selection: organisms that have favorable traits will survive better and pass those traits on to their offspring
Driven by competition among individuals for resources Individuals that can survive will be able to mate Traits are inherited by offspring Evolution by Natural Selection
Ecology: the study of the interactions of organisms and their environment Ecosystems= environmental communities Interdependence of Organisms
All life is interconnected When one aspect of the environment is harmed, it will have a negative impact on the whole ecosystem Fragile Environments
Matter, Energy, and Organization • Almost all energy on Earth comes from the sun • Photosynthesis- plants capture energy from the sun use it to manufacture glucose
Organisms that make their own food “self-feeders” Example: plants Autotrophs
Organisms that must take in food to meet their energy needs “other-feeders” Examples: rabbits, coyotes, bears Heterotrophs
Biology is the study of life, ranging from the study of unicellular organisms to the study of global interactions among millions of organisms Conclusion