chapters 1 & 2 Flashcards
levels of biological organization
molecules, organelles, cells, tissues, organs, organ system, organisms, populations, communities, ecosystems, biosphere
structure and function
structure gives us clues about what it does and how it works
function provides insight into its structure and organization
(shape determines its function)
cell theory
all living organisms are made from cells
eukaryotic and prokaryotic cells
cells of bacteria and archaea are prokaryotic
all other forms of life are composed of eukaryotic cells
eukaryotic cells
has membrane enclosed organelles
prokaryotes
simple, smaller, does not contain a nucleus or other membrane enclosed organelles
DNA
consists of chromosomes
genes
-units of inheritance
-encode information for building the molecules synthesized within the cell
-genetic information encoded by DNA directs the development of an organism
structure of DNA
-accounts for its ability to store information
-made up of two long chains arranged in a double helix
-each chain is made up of four chemical building blocks called nucleotides
(AGCT)
gene expression
process of converting information from gene to cellular product
Protein encoding
DNA is transcribed into RNA which is translated into protein
chemical cycling
-when organisms use energy to preform work, some energy is lost to the surroundings as heat
-energy flows through the ecosystem and enters light
feedback regulation
output or product of process
(reduces the initial stimulus)
negative feedback
response reduces initial stimulus
positive feedback
end product speeds up its own production
example of negative feedback
body temperature regulation
-if temp is too high, the body will start several processes to lower it
example of positive feedback
blood clotting after an injury to stop the bleeding
homeostasis
state of balance among the body to survive and function properly
maintaining internal stability while undergoing external changes
(stability & equilibrium)
three domains of life
bacteria, archaea, eukarya
