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
Proterobacteria
a large and diverse group that includes photoautotrophs, chemoautotrophs, and heterotrophs.
Prokaryotes
Spirochetes
Move by a spiraling corkscrew motion.
Free living and parasitic.
Syphilis and lyme disease
Prokaryotes
Archaea
Group includes many extremophiles (thermophiles, halophiles, methanogens)
Many look a lot like fossils that have been dates at more than 2 billion years old
Prokaryotes
Eukaryotes
Nuclei
usually posses membrane bound organelles
between 11 and 20 eukaryote kingdoms
Where is it most likely the first Eukaryotes came from?
an amalgam of prokaryote species, and possibly a viral component as well.
Protists
Eukaryotes that are single celled for most of their lives
some have acquired photosynthesis and became algae.
Fungi
includes decomposers, parasites, and mutualisms.
4 major groups of fungi
Chrytridomycots
Zygomycots
Ascomycots
Basidiomycots
Viridiplantae
- includes the green plants and the basal “bush” from which they originated. They have chlorophyls a and b, as well as certain other distinguishing characteristics.
- Green Algae-Chlorophytes
- Charophytes
- Plants
True Plants
multiterrestrial, photosynthesizers, terrestrial. Includes *gynosperms *angiosperms *ferns *mosses
Animals
Animals are a true lineage of multicellular organisms evolved from one line of protists
How many present day phylums are there?
About 30
biological population
Many individuals of a single species
biological communities
Populations of organisms tend to assemble into these
biodiversity
Genetic diversity within populations
Diversity of species or lineages (taxonomic diversity)
communities and ecosystems
Genetic diversity
example-variation of cultivated plants such as tomatoes.
Taxonomic diversity
Number of different species a habitat contains.
How many species of snakes are in California?
73 in various families
Major areas of unexplored biodiversity
Tropical rainforest (cover 6% of the land are, but 4/5 of all plant species and 1/2 the animals are found there), ocean floor (70% of the world’s surface, estimated to be 95% unexplored) microbial world
the first pollinators were probably
herbivores attracted to pollen as a source of food.
talk about hawkmoths and long corollas
A flower evolves a long corolla to ensure that hawkmoth visitors must reach deeply into a flower in order to reach the nectar “reward” provided by the flower, thus placing their faces in the appropriate location to receive pollen.
The hawkmoths respond by evolving longer tongues, to enable them to more easily reach the nectaries of the flowers.
This, in turn, places selective pressure on the flowers, and intensifies the relationship.
The longer nectary, in turn, makes it nearly impossible for long-tongued bees to visit the flowers, and drives the system toward an obligate mutualism, rather than a looser, facultative mutualism
The most common pollintation “syndromes”
Most flies and generalists (most beetles)-open flowers, easy to reach pollen, accessible nectaries. Large amounts of pollen because most of the visitors are after pollen. Usually early spring.
Long-tongued bees-moderately long corollas, flowers are white, blue, yellow, infrared, sucrose-concentrated nectar, sometimes a “landing pad” for bees, and sometimes petals that must be pushed apart for the bee to reach the nectar. Scented flowers, open in daytime. Sticky pollen that bees can easily collect and transport, nectar guides.
Short-tongued bees-white, yellow, infrared flowers, short corollas with easily available pollen, no special tricks with petals, but usually asymmetric. Scented flowers open in daytime. Sticky pollen. Sucrose-dominated nectar.
Bumblebees, Amigillia bees-as with long-tongued bee flowers, but bee must hang upside and buzz to release pollen.
Polination syndrome of butterflies
flowers run more to the pink or lavender and have a landing platform.
polination syndrome of hummingbirds
-red flowers (only vertebrates see that color well) with very long corollas and large amounts of dilute nectar, flowers open in daytime, and bird is forced to push face into stamens in order to feed. No scent.
polination syndrome of bats
large amounts of dusty pollen that will stick to mammal hairs, very big flowers that bats can reach into with their faces, open at night,
pollination syndrome of carrion beatles and flies
flowers smell like carrion and offer large amounts of pollen
Ecology
the scientific study of the distribution and abundance of organisms, and their interactions with the environment.
hypothesis
constructed based on all the pertinent observations.
scientific paradigms
Scientific paradigms are explanations for how the world works, they inspire future research, but also limit its direction to certain avenues.
Individuals
single, discrete organisms. ex-a mouse, a person. can be difficult with trees or fungus.
organismal ecology.
ex- How a cave cricket gets in and out of the cave safely.
populations
groups of organisms of the same species living in the same place.
ex-a herd of wildebeast, all the catfish in a pond, E. Coli in a person’s gut.
population ecology
Very frequently, these questions concern abundance, density, population growth, and limits to growth. For instance, a population ecologist might study the extent to which the number of available nest sites affects the maximum number of tropicbirds an island can sustain.
Communities
assemblages of populations of different species living in the same place.
community ecology
might ask questions about the extent to which parasitic wasps control outbreaks of pine sawflies, and whether the presence of parasitoids is necessary for the presence of pine trees.
Ecosystems
interacting assemblages of living things living in a particular area, accounting also for the nonliving components, such as light, water, nutrients, soil, and seasonality, that are important to life.
ecosystems ecology
studying caves might ask questions about the role of bat guano entering the caves, and the extent to which nutrients and energy brought in by the bats from outside, via their guano, support the nonphotosynthetic ecosystem in the cave.
Biological Species Concept
“A species is a group of actually or potentially interbreeding organisms that can mate and produce fertile offspring” –Ernst Mayer
This definition is very interesting from an evolutionary perspective. It defines species as “real”, objective entities, defined by the limits of gene exchange
Morphological Species
More subjective than the biological species concept.
“Species are Groups of Organisms that Share Certain Morphological or Biochemical Traits”
Some species do not reproduce sexually, some are known only from fossils. This definition is the working definition used by biologists that cannot, or should not, use the “Biological Species Concept”
Phylogenetic Species Concept
A species is a discrete lineage, propagated, ancestor to descendent through time, which is recognizably different from other such lineages and shares a distinct evolutionary history.
It defines a species by its relationship to other species.
