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Biology 2B Exam 1
Exam 1 Chapters 25-30
55
Biology
Undergraduate 3
09/18/2012

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Term
4 stages of chemical/physical processes that likely led to first living cells
Definition
1. Abiotic synthesis of small organic molecules (monomers)
2. Joining of these small molecules into polymers
3. Packaging of molecules into protocells
4. Origin of self-replicating molecules that made inheritance possible
Term
define fossil and examples of types
Definition
Preserved remnants or impressions left by organisms that lived in the past
ex- rock, tree, amber
-examine fossils to help establish relationships between living organisms
•Sedimentary rocks are the richest source of fossils
–deposited into layers called strata
•Based on the sequence in which fossils have accumulated in such strata
•Fossils reveal ancestral characteristics that may have been lost over time
•Biased and incomplete documentation
Term
How long ago the earth first formed
Definition
about 4.6 billion years ago
Term
How long ago prokaryotes most likely evolved
Definition
•The oldest known fossils are stromatolites, rocklike structures composed of many layers of bacteria and sediment
•Stromatolites date back 3.5 billion years ago
•Prokaryotes were Earth’s sole inhabitants from 3.5 to about 2 billion years ago
Term
How long ago eukaryotes most likely evolved-and most supported theory
Definition
Oldest fossils of eukaryotic cells date back 2.1 billion years
endosymbiosis: mitochondria and plastids were formerly small prokaryotes living within larger host cells, eventually became single cell
Term
How long ago multicellular eukaryotes evolved
Definition
•After the first eukaryotes evolved, a great range of unicellular forms evolved, then multicellular forms evolved
•Molecular clocks: common ancestor of multicellular eukaryotes lived 1.5 billion years ago
•Oldest known fossils: small algae that lived about 1.2 billion years ago
Term
How long ago major groups of larger eukaryotes colonized land
Definition
•Most of the major phyla of animals appear in the fossil record of the Cambrian period (535-525 million years ago)
–Cambrian explosion
–Prior animals were soft-bodied
Term
define phylogeny
Definition
the evolutionary history of a species or group of related species
Term
define homology and analogy; know examples of each
Definition
Homology: similarity due to shared ancestry
-ex: flipper and hands
Analogy: similarity due to convergent evolution
-ex: wings
Term
define taxonomy
Definition
ordered division of organisms into categories based on characteristics
Term
understand way to name organisms using binomial nomenclature
Definition
•Binomial: two-part scientific name of a species
•First part = genus
•Second part = specific epithet-unique for each species
•First letter of the genus is capitalized, and entire name is italicized
•Both parts together name the species (not the specific epithet alone)
Term
know names and order of levels in hierarchical classification
Definition
species, genus, family, order, class, phylum, kingdom, domain
Term
Classification systems: original 2 groups, 5 kingdoms, present 3 domains
Definition
2 groups : plants and animals
5 kingdoms: Monera, Protista, Plantae, Fungi, and Animalia
present 3 domains: Archaea, Bacteria, and Eukarya
Term
Basic structure and functions of cell wall
Definition
maintains cell shape, provides physical protection, and prevents the cell from bursting in a hypotonic environment
Term
Names of cell surface structures
Definition
Capsules and fimbriae often surround cell wall
–Help adhere to substrate or each other
Some have flagella for movement
Term
Components of internal cell structure
Definition
•Usually lack complex compartmentalization, but some do have specialized membranes that perform metabolic functions
•Typical genome: circular chromosome that lacks a membrane and located in a nucleoid region
•Usually also has smaller independent rings of DNA
Term
Know basic differences of 4 modes of nutrition
Definition
–photoautotrophy- light (CO2)
–chemoautotrophy- inorganic chemicals (CO2)
–photoheterotrophy- light (organic compounds)
–chemoheterotrophy- organic compounds (organic compounds)
Term
Define 3 types of metabolism in relation to oxygen
Definition
–Obligate aerobes: require oxygen
–Facultative anaerobes: can survive with or without oxygen
–Obligate anaerobes: poisoned by oxygen
Term
2 major groups of prokaryotes
Definition
Bacteria, Archea
Term
Names and major distinguishing traits (from lecture) of 5 groups of Bacteria
Definition
Proteobacteria
–clade of gram-negative members
–5 subgroups
Gram-positive bacteria
-very diverse group
-Streptomyces, Bacillus anthracis
Chlamydias
–Parasites of animals
–Gram-negative but lack petidoglycan
Spirochetes
–Move by spiraling through environment
–Free-living and parasitic
Cyanobacteria
–Conduct plant-like photosynthesis
–Major component of phytoplankton
Term
Types of Archaea
Definition
thermophiles- thrive in very hot environments
halophiles- live in high saline environments
methanogens- live in swamps and marshes and produce methane as a waste product
Term
Roles of prokaryotes in biosphere
Definition
•Play major role in the continual recycling of chemical elements between the living and nonliving components of ecosystems
•Chemoheterotrophic prokaryotes function as decomposers
•Nitrogen-fixing prokaryotes make atmospheric N into useable forms (ammonia)
•Many live with other organisms in symbiotic relationships
Term
Major types of symbiotic relationships
Definition
Mutualism-both species benefit
Commensalism-1 species benefits, other not harmed or helped
Parasitism-parasite feeds off of host
–Disease causing parasites= pathogen
Term
Examples of harmful imapcts of bacteria
Definition
Pathogenic prokaryotes: cause about half of all human diseases
Typically cause disease by releasing exotoxins or endotoxins
Exotoxins: proteins secreted cause disease
Endotoxins: released only when bacteria die and cell walls break down
Many are potential weapons of bioterrorism
Term
Examples of beneficial impacts of bacteria
Definition
Important advances in DNA technology
Principal agents in bioremediation: use of organisms to remove pollutants from the environment
Synthesis of vitamins
Production of antibiotics, hormones, and food products
Term
Nutritional methods
Definition
Photoautotrophs- which contain chloroplasts
Heterotrophs- which absorb organic molecules or ingest larger food particles
Mixotrophs- which combine photosynthesis and heterotrophic nutrition
Term
Describe endosymbiosis
Definition
process where unicellular organism engulfs other cell, which eventually becomes organelle
-Considerable evidence that much of protist diversity has its origins in endosymbiosis
Term
Names of 5 supergroups and defining characteristics
Definition
Excavata-
Chromalveolata-
Rhizaria-
Archaeplastida-includes plants-
Unikonta-includes fungi and animals-
Term
5 major terrestrial adaptations of land plants
Definition
•Apical meristems
•Alternation of generations
•Walled spores produced in sporangia
•Multicellular gametangia
•Multicellular, dependent embryos
Term
Details of general alternation of generations (very familiar with cycle, ploidy and processes)
Definition
Gametophyte:
–produce gametes (egg and sperm) which unite to form zygote
•Sporophyte:
–produce haploid reproductive cells (spores) through meiosis that develop into gametophyte without fusing with another cell
–produced from mitotic division of the diploid zygote
Term
Know shift in dominance of sporophyte/gametophyte in all major groups
Definition
In bryophytes, the gametophyte is the “dominant” generation, larger and more conspicuous than the sporophyte
In pteridophytes, gymnosperms, and angiosperms, the sporophyte is the dominant generation
Term
How long ago land plants evolved
Definition
Fossil evidence indicates that plants were on land at least 475 million years ago
Term
General characteristics of bryophytes, 3 major types,
Definition
Liverworts, phylum Hepatophyta
Hornworts, phylum Anthocerophyta
Mosses, phylum Bryophyta
Term
How long ago vascular plants evolved
Definition
Fossils ancient of vascular plants date back about 420 million years
Term
Names and function of 2 types of vascular tissue
Definition
•Xylem conducts most of the water and minerals and includes dead cells called tracheids
•Phloem consists of living cells and distributes sugars, amino acids, and other organic products
Term
Evolution of roots
Definition
Roots: organs that anchor vascular plants
•Enable vascular plants to absorb water and nutrients from the soil
•Roots may have evolved from subterranean stems
Term
Define homosporous and heterosporous
Definition
homosporous-produce one type of spore that develops into a bisexual gametophyte
heterosporous-have two types of spores that give rise to male and female gametophytes
Term
General characteristics and examples of Lycophyta (seedless vascular plants)
Definition
–Giant lycophytes thrived for millions of years in moist swamps
–Surviving species are small herbaceous plants
–Includes club mosses, spike mosses, and quillworts
Term
Ecological significance of bryophytes and seedless vascular plants
Definition
•Ancestors of modern lycophytes, horsetails, and ferns grew to great heights during the Carboniferous period, forming the first forests
•These forests may have helped produce the global cooling at the end of the Carboniferous period
•Decaying plants of these Carboniferous forests eventually became coal
Term
Bryophote characteristics of gametophyte
Definition
–Produce flagellated sperm in antheridia
–Produce egg in archegonia
–Generally form ground-hugging carpets and only a few cells thick
Term
Bryophte characteristics of sporophyte
Definition
–Grow out of archegonia
–Consist of a foot, a seta, and a sporangium
Term
Evolution of leaves
Definition
Leaves: organs that increase surface area of vascular plants-> capture more solar energy for photosynthesis
•Leaves are categorized into two types:
–microphylls (single vein) & megaphylls (highly branched vascular system)
•According to one model of evolution, microphylls evolved first, as outgrowths of stems
Term
General characteristics and examples of Pterophyta (seedless vascular plants)
Definition
Ferns are the most diverse seedless vascular plants, with more than 12,000 species
–Most diverse in the tropics but also thrive in temperate forests
–Some species are even adapted to arid climates
•Includes ferns, horsetails, and whisk ferns and their relatives
Term
Name and describe the 5 key features of seed plants
Definition
–Reduced gametophytes
–Heterospory
–Ovules
–Pollen
–Seeds
Term
Classification of gymnosperms-know members/common names from all 4 phyla
Definition
•Transition to drier climates favored gymnosperms
–Needle-shaped leaves
•“naked seeds” : not enclosed in ovaries
•Seeds are exposed on modified leaves (sporophylls) that typically develop into cones (strobili)
•Include four phyla:
–Cycadophyta (cycads)
–Gingkophyta (one living species: Ginkgo biloba)
–Gnetophyta (three genera: Gnetum, Ephedra, Welwitschia)
–Coniferophyta (conifers, such as pine, fir, and redwood)
Term
Key features of gymnosperm life cycle
Definition
–Dominance of the sporophyte generation
–Transfer of sperm to ovules by pollen
–Development of seeds from fertilized ovules
Term
General characteristics of angiosperms
Definition
•All angiosperms are classified in a single phylum, Anthophyta
•Have reproductive structures called flowers and fruits
•They are the most widespread and diverse of all plants
Term
Define flower & know major structures of typical flower
Definition
specialized shoot with up to four types of modified leaves:
–Sepals: enclose the flower
–Petals: brightly colored and attract pollinators
–Stamens: produce pollen
–Carpels: produce ovules
Term
Define fruit
Definition
•A fruit typically consists of a mature ovary but can also include other flower parts
•Develops from ovules after fertilization
•Protect seeds and aid in their dispersal
•Mature fruits can be either fleshy or dry
•Various adaptations help disperse seeds
•Seeds can be carried by wind, water, or animals to new locations
Term
Key features of angiosperm life cycle
Definition
•Flower of sporophyte produces microspores and megaspores
•Pollen grains (male gametophytes) develop within anthers
•Ovule (within ovary) contains female gametophyte which produces egg
•Anther releases pollen and it lands on stigma of carpel
•Double fertilization: pollen tube discharges two sperm into the female gametophyte within an ovule
–1 sperm fertilizes the egg forming zygote (2n)
–Other sperm combines with two nuclei in the central cell of the female gametophyte producing endosperm (3n)
•endosperm nourishes developing embryo
Term
How long ago angiosperms evolved
Definition
Angiosperms originated at least 140 million years ago
Term
Angiosperm diversity-4 major divisions
Definition
Term
Key characteristics of monocot
Definition
Term
Human uses/products derived from seed plants
Definition
•No group of plants is more important to human survival than seed plants
•Plants are key sources of food, fuel, wood products, and medicine
•Our reliance on seed plants makes preservation of plant diversity critical
Term
Key characteristics of eudicot
Definition
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