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Chapter 1 : Introduction

Terms in this set (44)

evolution
the process of change that has transformed life on Earth ,

change in a kind of organism over time; process by which modern organisms have descended from ancient organisms
biology
scientific study of life
emergent properties
new properties emerge at each level in the biological hierarchy

arrangement and interactions of parts as complexity increases
i.e. photosynthesis requires specific organization of chlorophyl & chloroplast molecules
i.e. human thoughts/memories are emergent properties of a complex network of neurons, and if blow to head disrupts intricate set up
i.e. ecosystem level : the recycling of chem elements essential to life depends on a network of diverse organisms interacting wsith each other and with the soil, water and air

atoms => molecules => organelles => cells => tissues => organs & organ systems => organisms => populations => communities => ecosystems => the biosphere
reductionism
the approach of reducing complex systems to simpler components, easier to study, useful in biology

dilemmas : disrupting a living system interferes with its functioning
i.e. watson and crick studying extracted dna
dna better understood when studied with other molecules however

scientists must balance approach with holistic objective of understanding emergent properties, how parts/cells/ work together
system
a combination of components that function together
systems biology
i.e. a leaf, frog, ant colony, desert ecosystem

looking at change in one or more variables and how that will affect other components and the whole system
bio themes
- emergent properties

- organisms interact with other organisms and physical environment

- structure and function are correlated at all levels of biological organization "form fits function"

- life requires energy transfer and transformation

- the cell is an organisms basic unit of structure and function
cell
- an organism's basic unit of structure and function
- lowest level of organization that can perform all activities required for life
- all have membrane, regulating materials in and out, and have DNA as genetic info
eukaryotic cell
- membrane enclosed organelles
- in most, largest organelle is the nucleus, others in the cytoplasm
- plants and animals
prokaryotic cells
- simpler and usually smaller than eukaryotic
- DNA is not separated from the rest of a cell by membrane,
- lack other membrane enclosed organelles
microorganisms : bacteria & archaea
DNA
(biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix

transmits heritable info from parents to offspring,
program protein production of cell by being transcribed into mRNA then RNA
genes
the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein
gene expression
DNA transcribed into RNA and then translated into specific proteins

also results in RNAs that are not translated into proteins but still have important functions
negative feedback
A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.,

a mechanism of response in which a stimulus initiates reactions that reduce the stimulus
positive feedback
mechanism of homeostasis feedback that tends to magnify a process or increase its output
levels of bio organization
1. The Biosphere
2. Ecosystems
3. Communities
4. Populations
5. Organisms
6. Organ and Organ Systems
7. Tissues
8. Cells
9. Organelles
10. Molecules
biosphere
the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist
ecosystems
a specific biological community and its physical environment interacting in an exchange of matter and energy.
communities
Populations of different kinds of organisms that live in the same place at the same time
populations
groups of individuals that belong to the same species and live in the same area
organisms
individual living things
organs and organ systems
___________ are body parts consisting of two or more tissues; create teams that cooperate in a specific function (organ system)
tissues
groups of similar cells that perform a specific function in an organism
cells
The basic unit of all living things
organelles
tiny structures that carry out functions necessary for the cell to stay alive
molecules
groups of two or more atoms held together by chemical bonds
emergent properties
Due to increasing complexity, new properties emerge with each step upward in the hierarchy of biological order
ways to examine life
Discovery

Hypothesis
Discovery
What is it?
Where is it?
What does it do?
Hypothesis
If...then
hypothesis solving
Observations -> Questions ->
(use inductive reasoning to draw relative conclusion) Hypothesis ->
(use deductive reasoning) Predictions
-> Testing Predictions
-> Re-evaluation of Hypothesis
hypothesis
It must be testable

It must be falsifiable
genomics
large-scale analysis of the DNA sequences within a species as well as the comparison of sequences between species
Prokaryotic Cell
lack membrane-enclosed organelles (lack nucleus)

i.e. Bacteria, Archaea
Prokaryotes vs Eukaryotes
prokaryotes: "pre-nucleus"
eukaryote: "true nucleus",

prokaryotes lack a nucleus and membrane-bound organelles and have a region called nucleoid where there genetic material mainly is, prokaryotes also lack an internal membrane system
Eukaryotic Cell
cell with a nucleus (surrounded by its own membrane) and other internal organelles

in most - the largest organelle is the nucleus
negative feedback
one way that cells and multicellular organisms turn off casade of rxns

i.e. metabolizing food
theory
broad in scope, generates new hypotheses, and is supported by a large body of evidence
controlled experiments
empirical tests of theories in a controlled setting in which particular effects can be isolated (control groups)
natural selection
all life connected thru its long evolutionary history,

- a natural process resulting in the evolution of organisms best adapted to the environment

populations of organisms (hereditary variations)
environmental factors
organisms interact with other organisms and physical environment
plants take up nutrients from soil, and chemicals from air
life requires energy transfer and transformation
energy flows through ecosystem
all organisms must perform work, which requires energy
energy from sunlight converted to chemical energy by producers
structure and function are correlated at all levels of biological organization "form fits function"
the form of a biological structure suits its function and vice versa
the cell is an organisms basic unit of structure and function
lowest level of organization that can perform all activities required for life
either Euk or Prok
THIS SET IS OFTEN IN FOLDERS WITH...