CHAPTER 1 Flashcards
(40 cards)
Biology? What does biology help with and understand?
the scientific study of organisms, living and fossil
the goal -> is discovering and understanding the diversity and complex processes that make up life
common features shared among all life forms?
-exist in populations that evolve over time
-made of a common set of chemical compounds
-made up of cells
-use molecules from the environment to synthesize
-extract energy from the environment and use it to do work
-regulate their internal environment
-contain genetic information that enables them to develop, function, and reproduce
-use a universal genetic code to build proteins
what do our striking similarities in chemical compounds say about life?
it leads us to the conclusion that all life has a common ancestry
how long ago did earth form? how long did it take for life to evolve?
-earth formed 4.6 to 4.5 billion years ago
-life took about 600 million years to first form
what are the several elements essential for life to evolve?
-nucleic acids : that reproduce themselves and serve as templates for protein synthesis
-enclosure of biological molecules : by membranes (keep things in and out) made of fatty acids (non-soluble), sillier to liposomes
define liposome.
a spherical structure contained by a membrane of phospholipids
-can be used to deliver drugs to cells
define prokaryotes. what are the two main groups?
-unicellular organisms that do not have nucleic or other membrane-enclosed organelles
-two groups are bacteria and archaea (found in extreme environments)
define eukaryotes. define nucleus
-eukaryotes: organisms whose cells contain their genetic material inside a nucleus, and have membrane-enclosed organelles
-nucleus: contains genetic information
what is photosynthesis? when was it introduced in the earth? what were the first photo synthesizers? what does this mean for earth?
-photosynthesis-> metabolic processes carried out by plants and some microorganisms where sunlight is transformed to chemical energy; providing food for other organisms
-intoruced to earth 2.5 billion years ago
-photosynthetic cells similar to cyanobacteria(prokaryotic cells capable of photosynthesis) were the first photo synthesizers
-this means oxygen is introduced to the earths atmosphere
what evolved from the abundance of oxygen?
-organisms had an anaerobic metabolism which is occurring without the use of oxygen
-once oxygen was more abundant; organisms involved to have an aerobic metabolism which is occurring in the presence of oxygen
what did accumulating oxygen lead to?
-this lead to the formation of the ozone (O3) layer –> absorbs damaging UV radiation
-once there was enough ozone (500 million years ago) organisms were able to leave the protection of the water and move onto land
define cell specialization. what did it allow?
-cell specialization: is a division of labor such that different cell types become responsible for different functions
-which allowed multicellular organism to get larger, more efficient, and adapt to environments
define tissues
a group of similar cells organized into a functional unit
define organs
organs are composed of different tissues integrated to perform a distinct function
EX: heart, liver, brain, etc
define organ systems
an interrelated and integrated group of tissues and organs that work together in a physiological function
where do organisms acquire nutrients? what does the break down of nutrient molecules do? what types of work?
-organisms get nutrients from their environment
-the break down of nutrient molecules supplies raw material (to build organism’s structures) and energy to do work
-work: movement; biochemical work; electrical work in the nervous system
how do organisms regulate their internal environment?
-self-regulation to maintain a constant internal environment (self-regulation through homeostasis)
define homeostasis
the maintenance of a steady state, such as a constant temperature, by means of physiological or behavioral feedback responses
define sensory mechanisms? what is it used for?
-Regulation requires information about the internal and external environments, so organisms have sensory mechanisms.
define effector mechanisms? what is it used for?
-Effector mechanisms alter conditions.
define signaling mechanisms? what is it used for?
-Signaling mechanisms integrate information and enable communication between sensors and effectors.
what is the external hierarchy of the biological world?
Biosphere -> global ecosystem; entire portion of earth inhabited by life
Ecosystem -> a biological communist & its physical environment
Communities -> all organisms inhabiting & interacting in a particular area
Populations -> same species living & interacting with each other same place and time
Organisms -> individuals
Organ & Organ System -> structure of two or more tissues with specific functions; group of organs working together
Tissues -> group of similar cells with specific functions
Cells -> smallest unit of “life”
Organelles -> membrane-enclosed structure with a specialized function
Molecules -> group of two or more atoms held together by covalent bonds
Atoms -> smallest unit of matter
define biomes
the major ecosystems that cover board geographic areas with distinctive physical features and communities are known as biomes
define biosphere
all of the biomes on our plant make up the biosphere
