Week 1 and 2 Flashcards
Processes that define a living thing
- Organization and information
- Need for an energy source
- Reproduction and evolution
What happens when an organism breaks down and no longer maintains a certain level of organization
It dies
How do living things impose organization on non-living matter?
By growth, development, and reproduction
Homeostasis
A critical aspect of life’s organization is a constant internal environment, called homeostasis, which makes the complex biochemical machinery of life possible.
Living things use a template to impose order on nonliving things and to maintain order within their own bodies.
In present day living things this template is called
DNA
This template makes proteins, which are responsible for our structure, function, and metabolism-it is copied every time living things reproduce.
As close to the basis of life as we can get
DNA
All living things require a constant input of _________ to survive.
energy
dynamic equilibrium
an organized system that requires a constant input of energy to maintain itself.
What happens to an organism without an input of energy?
Organization breaks down and death is imminent.
heterotroph
Process energy that was originally captured by other living things.
autotroph
fix energy from the sunlight
chemoautotroph
fix energy by reducing hydrogen sulfide
When does the ambiguous nature of a virus become apparent?
Reproduction and evolution.
A virus alone is inert. It does not use energy and cannot reproduce. In the presence of the right living cells, however, viruses can direct the production of million copies of themselves.
species
1-can interbreed with eachother
2-share a set of common traits
3-an evolutionary lineage that persists, ancestor to dependent over time.
Approximately how many species are on earth
2 million described. Estimated to be 8.7 million, but may be much higher.
(1 million of these are insects)
What are some problems with the naming of species?
- It is complicated process to name a sepcies. (time consuming and demands special skills)
- difficultly with the concept of the species (cryptic species, species named more than once, etc.)
- Some species have been named several times
What is the problem with the naming of Allosaurus?
- There is a great deal of variation among specimens attributed to that species-and in reality, the fossils we have may have represented several species.
- Also the largest specimens are often placed in the genus Epanterias, or Saurophagnax-but we do not really know whether they were simply big individuals of A. fragilis.
Some of the taxa that are better known
birds, mammals, flowering plants, and butterflies are well known.
Some of the taxa that are not as well known
microorganisms, beetles, insects
The Tree of Life
- All organisms on Earth descend from a single, common ancestor.
- This ancestor may have been a single species, or a cluster of organisms freely exchanging genetic material.
- In scientific terms, the tree of life is a diagram representing the actual diversification of organisms from a common ancestor.
How do we know that there was only one common ancestor? Or that other unrelated forms have gone extinct?
- Except for a few virus, all forms of life on earth use DNA as genetic material
- All forms of life contain a very similar, almost identical genetic code
- All forms of life rely on the same biomolecules. (Amino acids, sugars, etc.)
The 5 Kingdoms
Plantae, protista, monera (includes all prokaryotes), fungi, animalia
Are prokaryotes closer to Eukaryotes or bacteria?
Eukaryotes
The major “domains” of living things
Prokaryote, Eukaryote, Bacteria
What is the chart that shows the 3 “domains of living things” based on
Ribosomal RNA
Prokaryotes
Most ancient, abundant and metabolically diverse organisms.
Describes a state of organization (no nucleus) rather than a taxonomic group
Includes bacteria and archaea