anatomy 1.4-1.6

theory of natural selection

explanation of how species originate and change through time; help understand the human body

Charles Darwin

influential biologist who presented first well supported theory of how evolution works

evolution

change in genetic composition of population of organisms

selection pressures

forces that promote reproductive success of some individuals more than others (ex: predators)

adaptations

inherited features of anatomy and physiology that evolved in response to pressures and that enable organism to succeed (example: better camouflage)

what are molecules composed of?

atoms

what are organelles composed of?

molecules

what are cells composed of?

partly of organelles

what are tissues composed of?

cells

what are organs composed of?

tissues

what are organ systems composed of?

organs

what is an organism composed of?

organ systems

what are the 2 complementary approaches to studying and understanding human life?

reductionism and holism

reductionism

theory that large, complex systems can be understood by studying their simpler components

holism

“emergent properties” occur as we ascend the levels of organization; these cannot be produced from the properties of individual parts alone

t or f: physiology is more variable than anatomy

true

what are the characteristics of life? (1/2)

organization, cellular composition, metabolism, responsiveness (excitability), and movement

organization

living things exhibit a higher level of organization than non living things

cellular composition

living matter is always compartmentalized into one or more cells

metabolism

the sum of internal chemical change

responsiveness (excitability)

ability to sense and react to changes in environment (stimuli)

movement

movement of entire organism or of substances within the organism

what are the characteristics of life? (2/2)

homeostasis, development, differentiation, reproduction, and evolution

homeostasis

the ability to detect change, activate mechanisms that oppose it, and maintainin relatively stable internal conditions

development

change in form or function over time

differentiation

transformation of unspecialized cells into cells with a committed task

growth

increase in size; occurs through chemical change

reproduction

organisms produce copies of themselves; pass genes to offspring

evolution

genetic change from generation to generation; occurs due to mutations (change in DNA structure)