Question | Answer |
what are the 3 levels of biodiversity? | Genetic diversity, species diversity, and ecosystem diversity. |
Biophilia | Innate bond between humans and other living systems. |
what is the gradient hypothesis | Time hypothesis: community diversity with age.
Area hypothesis: larger areas contain more species.
Productivity hypothesis: greater production by plants increase animal number. |
what is loss of biodiversity? | Introduced species: competition, predation, disease.
Direct exploitation: over harvesting
Habitat destruction: deforestation |
Areas rich in Endemic species | Hot spots. |
indicator species | spp whose status provided into an overall health of ecosystem. (lichens) |
Umbrella species | protecting these species would protect many other spp |
flagship species | single large or instantly recognizable species |
keystone species | spp within a community that have a role out of proportion to their abundance. |
Chapter 23 | COMING UP |
Biological evolution | a heritable change that in one or more characteristics of a population or species across many generations. |
Population | members of the same species that are likely to encounter each other, and so have the opportunity to interbreed. |
Molecular evolution | the molecular changes in genetic material that underlie the phenotypic changes associated with evolution. |
Empirical thought | relies on observation to form and idea or hypothesis. |
Biogeography | the study of the geographical distribution of extinct and modern species. |
Endemic | naturally found in only one particular location. |
Convergent evolution | when two different species from different lineages show similar characteristics because they occupy similar environments. |
Analogous structures | when species have similar characteristics even though they are not closely related |
alleles | different forms of a particular gene, that determine the trait. |
Homology | a fundamental similarity that occurs due to descent from a common ancestor. |
Homologous structures | bodily parts considered to be derived from a common ancestor. |
Vestigial structures | natomical features that have no apparent function but resemble structures of their presumed ancestors. |
Anatomical Homologies | the theory of evolution provides a sensible framework for understanding the diversity of life. |
Developmental homologies | the way that animals undergo embryonic development. |
Molecular homologies | similarities found which indicate that living species evolved from a common ancestor or interrelated group of common ancestors. |
Homologous genes | when two genes are derived from the same ancestral gene. |
Orthologs | genes that are homologous yet from different species. |
Paralogs | two or more homologous genes found within a single species. |
Gene family | consists of two or more copies of paralogous genes within the genome of a single organism. |
Myoglobin | stores oxygen in muscle cells. |
Hemoglobin | found in red blood cells and carries oxygen throughout the body. |
Exon shuffle | mutation. An exon and the flanking introns are inserted into a gene, thereby producing a new gene that encodes a protein with an additional domain. |
Vertical evolution | species evolve from pre-existing species by the accumulation of gene mutations, gene duplications, and exon shuffling. |
Horizontal gene transfer | genetic changes involving the exchange of genetic material among different species. |
Bacterial species may carry out three natural mechanisms of gene transfer known as: | conjugation, transformation, and transduction. |
chapter 25 | NEXT |
Speciation | the mechanisms that promote the formation of new species. |
Macroevolution | evolutionary changes that create new species and groups of species. |
Microevolutionary changes | those that occur in a single gene. |
Subspecies | when two or more groups within the same species display one or more traits that are somewhat different but not enough to warrant their placement into different species. |
the characteristics used by biologists to identify a species. | Physical or morphological traits, the ability to interbreed, common evolutionary lineages, and ecological factors |
Phylogenetic species concept | the members of a single species are identified by having a unique combination of characteristics. |
Biological species concept | a species is a group of individuals whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring but cannot interbreed with members of the other species. |
Evolutionary species concept | a species is derived from a single lineage that is distinct from other lineages and has its own evolutionary tendencies and historical fate. (based on ancestry) |
lineage | the genetic relationship between an individual or group of individuals and its ancestors. |
Ecological species concept | a viewpoint that considers a species within its native environment. |
ecological niche | he unique set of habitat resources that a species requires, as well as its influence on the environment and other species. Within their own nice, members will compete for survival. |
prezygotic mechanisms | prevent the formation of a zygote. habitat, temporal, behavioral, mechanical, and gametic isolation. |
postzygotic mechanisms | block the development of a viable and fertile individual after fertilization has taken place.
Hybrid inviability, hybrid sterility, and hybrid breakdown. |
hybrid inviability | when the fertilized egg cannot develop past the embryonic stages. |
hybrid sterility | when an interspecies hybrid may be viable but sterile. |
hybrid breakdown | changes in the chromosome structure. |
Interspecies hybrid | the offspring of two species. |
Anagenesis | a single species is transformed into a different species over the course of many generations. |
Cladogenesis | involves the division of a species into two or more species. |
Allopatric speciation | when gene flow becomes limited between two or more populations. Geographic isolation can promote allopatric speciation. |
Adaptive radiation | a single ancestral species has evolved into a wide array of descendant species that differ in their habitat, form, or behavior.
(form of allopatric speciation) |
Hybrid zones | where two populations can interbreed. |
Sympatric speciation | occurs when members of a species that initially occupy the same habitat within the same range diverge into two or more different species. |
Gradualism | each new species evolves continuously over long spans of time. |
Punctuated equilibrium | the tempo of evolution is more sporadic. Species exist relatively unchanged for many generations. |
Evolutionary-developmental biology | a field of biology that compares the development of different organisms in attempt to understand ancestral relationships between organisms and the developmental mechanisms that bring about evolutionary change. |
Allometric growth | the pattern whereby different parts of the body grow at different rates with respect to each other. |
Paedomorphosis | the retention of juvenile traits in an adult organism. |
Pax6 | a master control gene. Controls the expression of many other genes and thereby influences eye development in both rodents and humans. |
Chapter 26 and 27 notes | now |
Taxonomy | The field of biology that is concerned with the theory, practice, and rules of classifying living and extinct organisms and viruses. |
Systematics | the study of biological diversity and the evolutionary relationships among organisms, both extinct and modern. |
Hierarchy | a system of organization that involves successive levels. |
Taxon | smaller hierarchical groups. |
Kingdom | highest and most inclusive taxonomic group. |
five kingdom system. | Monera, Protista, Fungi, Plantae, and animalia. |
Binomial Nomenclature | the standard method for naming species. |
all forms of life are within three domains: | Bacteria, Archea, and Eukarya. |
Eukarya- four eukaryotic kingdoms: | Protista, Fungi, Plantae, and Animalia. |
Phyla | classes, orders, families, genera. |
Chordata Phylum | Fishes, reptiles, and mammals. |
Extremophiles | organisms that occur primarily in extreme habitats. |
hyperthermophiles | archaea that will not grow when temp is less than 84*C |
Extreme Halophiles | occupy evaporation ponds used to produce salt from seawater. |
Hyperthermophilic | An archaeal species that can only grow at extremely high temperatures |
Crenarchaeota | Organisms that grow in extremely hot or cold habitats. |
Euryarchaeota | methane producers and extreme halophiles. |
Korarchaeota | primarily know from DNA sequences found in samples from hot springs. |
Nanoarchaeota | the hyperthermophile nanoarchaem equitans, which appears to be a parasite of the thermal vent crenarchaeote ignicoccus. |
Thylakoids | intracellular tubules produced from light energy from cyanobacteria and other photosynthetic bacteria. |
Magnetosomes | produced from mutant bacteria lacking a functional form of an actin-like protein. Scatter around mutant cells, disrupting their ability to detect a magnetic field. |
microbial cells occurs in five major shapes | spheres(cocci), rods(bacilli), comma-shaped cells(vibrios), and spiral shaped cells that are either flexible(spirochaetes) or rigid(spirilli). |
Biofilms | Aggregations of microorganism that secrete adhesive mucilage, thereby gluing themselves to surfaces. |
Gram stain | procedure to detect and distinguish bacteria more easily. |
Pili | hreadlike cell surface structures that allow some prokaryotes to twitch or glide across surfaces. |
Gas vesicles | cyanobacteria and other bacteria that live in aquatic habitats use cytoplasmic structures to adjust their buoyancy. |
Binary fission | the cells of bacteria and archaea divide by splitting in two. |
Akinetes | aquatic filamentous cyanobacteria often produce large, food filled akinetes when winter approaches. |
Endospores | cells having tough protein coats that are produced inside bacterial cells and then released when the enclosing cell dies and breaks down. |
Transduction | a process when DNA may enter cells by means of viral vectors. |
Transformation | a process in which microbes are able to take up DNA directly from their environments. |
Conjugation | a mating process in which some bacteria transmit DNA. |
Photoautotrophs | able to use light as a source of energy for synthesis of organic compounds from CO2 and H2O, or H2S. |
Chemoautotrophs | able to use energy obtained by chemical modifications of inorganic compounds to synthesize organic compounds. |
Photoheterotrophs | able to use light energy to generate ATP, but they must take in organic compounds from their env. |
Chemoheterotrophs | must obtain organic molecules for both energy and as a carbon source. |
Diazotrophs | dinitrogen consumers |
Nitrogen fixation | specialized metabolic process. The removal of nitrogen from the gaseous phase is called fixation. Provide ammonia to the plant partner. |
Heterocysts | specialized cells in which many cyanobacteria accomplish nitrogen fixation. |
Producers | synthesize the organic compounds used by other organisms for food. |
Decomposers | break down dead organisms and organic matter, releasing minerals for uptake by living things. |
Methanotrophs | aerobic bacteria that maintains the balance of methane in earths atmosphere. |
Symbiosis | symbiotic associations with eukaryotic organisms. |
Pathogens | hosts that have disease symptoms due to parasitic microbes. |
Chapter 28 | NOW |
3 major ecological groups of protists | algae, protozoa, fungus |
Plankton | swimming or floating protists. Also includes bacteria, viruses, and small animals. |
Phytoplankton | the photosynthetic protists in plankton |
Protozoan plankton | heterotrophic plankton. |
Periphyton | communities of microorganisms that are attached by mucilage to underwater surfaces. |
Flagellates | protists that use flagella to move under water. |
Ciliates | protists that move by means of cilia.(tiny hairlike extensions on the outside of cells) |
Amoebae | protists that move by pseudopodia.(involves extending protist cytoplasm) |
phagotrophy | heterotrophic protists that specialize in phagotrophy.(particle eating) |
osmotrophs | Protists that rely on osmotrophy.(uptake of small organic molecules) |
autotrophs | photosynthetic protists. (organisms that can make their own organic nutrients) |
mixotrophs | protists that are able to use autotrophy, phagotrophy, or osmotrophy to obtain organic nutrients. |
saprobes | heterotrophic protists that feed on nonliving organic material that function as decomposers. |
zygotic life style | unicellular protists reproduce sexually this way. |
sporic life cycles | multicellular protists reproduce sexually this way. |
gametic life cycles | diatoms display this. All cells except the games are diploid, and gametes are produced by meiosis. |
climate sexual reproduction | ciliates reproduce this way. Conjugation. |