Bio Quiz 1

Bacteria and archaea, protists, fungi, animal diversity, invertebrates

positive phototaxis

the directed movement of a cell or organism towards a source of light

negative phototaxis

the directed movement of a cell or organism away from a source of light

endospores

useful for surviving long term harsh environments

binary fission

when an organism splits into two identical individual organisms without sex taking place; most preferred method of reproduction for prokaryotes

phototroph

energy from light only

chemotroph

energy from chemicals

autotroph

energy from CO2

heterotroph

energy from at least one organic compound

obligate aerobe

An organism that requires oxygen for its survival and growth

facultative anaerobe

Organism capable of surviving and growing with or without oxygen

obligate anaerobe

A microorganism that can only survive and grow in the absence of oxygen

bio remediation

using organisms to remove pollutants from water, air, and soil

What are the two main branches of prokaryotic evolution

bacteria and archaea

what are the components of a prokaryotic cell wall?

peptidoglycan, a polymer made of alternating sugar molecules cross-linked by peptide chains.

difference between gram-pos and gram-neg gram stains

gram pos shows up as blue or purple (contains peptidoglycan); gram neg shows up as red or pink (lacks peptidoglycan)

prokaryote cell wall function

maintains the cells shape, protects interior, and prevents cell from bursting when absorbing water

why are gram neg pathogens more threatening than gram pos?

the outer membrane protects against host defenses causing it to be antibiotic resistant

how does penicillin inhibit prokaryote growth?

inhibits cross-link information, which interferes with cell wall function

capsule

polysaccharide layer outside of the cell envelope; protects bacteria from toxic compounds and allows them to adhere to surfaces to avoid the immune system

fimbriae

chains of proteins on the outside of cells that allow them to adhere to other bacteria and surfaces

what are the major differences between prokaryotes and eukaryotes?

prokaryotes lack compartmentalization, have simpler structures, and may contain plasmids. eukaryotes also contain differing ribosomes than prokaryotes

plasmid

A small, circular DNA molecule that can replicate independently of the chromosomal DNA. It is commonly found in bacteria and can be used as a vector in genetic engineering to transfer genes between organisms

how do the antibiotics erythromycin and tetracycline inhibit bacterial growth?

by interfering in protein synthesis or destroying the cell wall

horizontal gene transfer

Process in which genetic material is transferred between different organisms that are not parent and offspring

three types of horizontal gene transfer

transduction, transformation, and conjugation

photoautotrophs

Organisms that can produce their own food using sunlight as an energy source. They convert light energy into chemical energy through photosynthesis.

chemoautotrophs

Organisms that can produce their own energy through chemical reactions instead of relying on sunlight or organic matter. They obtain energy by oxidizing inorganic compounds such as hydrogen sulfide or ammonia.

photoheterotrophs

Organisms that obtain energy from organic compounds but cannot convert light energy into chemical energy. They rely on consuming organic matter produced by other organisms for their energy needs.

chemoheterotrophs

Organisms that obtain energy by breaking down organic molecules through cellular respiration. They cannot produce their own food and rely on consuming other organisms or organic matter for energy.

what advantage does metabolic cooperation confer?

enables the sharing of metabolites as well as metabolic specialization of single cells

biofilm

A complex community of microorganisms that adhere to surfaces and form a protective matrix. They can be found in various environments, such as on teeth, medical devices, and pipes. They are known for their resistance to antibiotics and disinfectants, making them difficult to eradicate.

extreme thermophile

microorganisms adapted to temperatures normally found only in hot springs, hydrothermal vents, and similar sites of geothermal activity

extreme halophile

microorganisms that prefer saltier enviroments

methanogen

produce methane to reduce the biological demand for oxygen

symbiosis

an ecological relationship between organisms of different species that are in direct contact

three types of symbiosis

mutualism, commensalism, parasitism

opportunistic pathogen

organisms that can become pathogenic following a perturbation to their host

endotoxin

toxin that is released when a cell degenerates; sometimes responsible for disease

exotoxin

toxin that causes damage to the host by destroying cells or disrupting normal cell metabolism

why are antibiotic resistant bacteria on the rise?

the mis-use or overuse of antibiotics, as well as poor infection prevention and control

protists

a group of mostly multicellular eukaryotes

eukaryote

an organism whose cell contains a complex structure, nucleus, and a membrane

definitive host

organism in which a parasite reproduces sexually

intermediate host

organism in which a parasite does not reproduce sexually

how were protists first discovered and by whom?

antoni van leeuwenhoek; viewed a drop of pond water under a light microscope- he saw unicellular protists and prokaryotes

how do prokaryotes differ from protists?

protists are eukaryotes, meaning they have a nucleus and other membrane-bound organelles

why are protists now organized into four supergroups rather than a single kingdom?

our understanding of the evolutionary history of protists is in a constant state of flux

excavates

diplomonada and parabasalida; euglenozoans (kinetoplastids and euglenids)

SAR clade

stramenopiles (diatoms, golden algae, and brown algae), alveolates (dinoflagellates, apicomplexans, and ciliates), rhizarians (radiolarians, forams, and cercozoans)

archaeplastida

red algae, green algae, and land plants

unikonta

amoebozoans (slime molds, tubulinids, entamoebas), opisthokonts

kinetoplastid

free-living species that are consumers of prokaryotes in freshwater, marine, and moist terrestrial ecosystems

kinetoplast

contains multiple copies of mitochondrial DNA

what are three human diseases that involve kinetoplastids

african sleeping sickness, chagas disease, and leishmaniasis

what is the vector for african sleeping sickness

tsetse fly

what is chagas disease? what is the vector and how is the disease transmitted?

an inflammatory, infectious disease caused by a parasite found in the feces of the triatomine (reduviid) bug

what is the vector for leishmaniasis?

phlebotomine sandfly; protozoan parasite

what is a “red tide”? what organism is responsible for producing it and what are its effects?

harmful algae blooms caused by dinoflagellate blooms. aerosols from this algae can produce respiratory ailments including coughing, sneezing, or tearing

mixotroph

an organism that can combine photosynthesis and heterotrophic methods for nutrition

what is an apicomplexan? from what structure does it get its name?

a large phylum of parasitic alveolates. the name comes from the apicoplast, a unique form of organelle

what is the life cycle of the malaria parasite?

starts inside the mosquito- fertilization>zygote>meiosis>sporozoites

mosquito>>inside human- liver>liver cell> memrozoite> red blood cells> gametocytes>gametes

what is a ciliate? what is a distinctive feature of this group?

large varied group of protists named for their use of cilia to move and feed. have two distinct types of nuclei (micronuclei and macronuclei)

what are some characteristics of diatoms?

unicellular algae with a unique two-part, glass-like wall of silicon dioxide, major component of phytoplankton, highly diverse

what role do diatoms play in the biological carbon pump?

the fertilization of the ocean promotes diatom blooms. this moves CO2 from the atmosphere to the ocean floor. this causes all dead organisms to fall to the ocean floor. this removes CO2 from the atmosphere and “pumps” it into the ocean floor

golden algae

most are unicellular, but some are colonial

brown algae

all are multicellular; largest and most complex algae

red algae

usually multicellular; seaweeds

green algae

named for their green chloroplasts

what is a slime mold?

mycetozoans (fungi)

what is the primary difference between a plasmodial slime mold and a cellular slime mold?

plasmodial slime molds are a diploid organism while a cellular slime mold is a haploid organism

hyphae

tubular walls that surround plasma membranes and cytoplasm

septa

a wall, dividing a cavity or structure into smaller ones

haustoria

highly modified stem of a parasitic plant that originates from the hypha of a fungus

haploid

the presence of a single set of chromosomes within an organism’s cells

diploid

the presence of two complete sets of chromosomes within an organism’s cells

heterokaryon

a multinucleate cell that contains genetically different nuclei

zygosporangium

a thick-walled structure that is capable of surviving environmental extremes

asci

a saclike structure produced by fungi of the phylum in which sexually produced spores are formed

ascocarp

the fruiting body of a sac fungus (asomycete)

conidia

specialized hyphae spores in which the asexual reproduction of ascocarps happens

basidiocarp

elaborate fruiting bodies produced when mycelium reproduce. an example would be mushrooms

how does a fungus differ from a plant?

fungi are closer to animals than plants on a molecular level

how does a fungus differ from an animal?

fungi digest food outside the body by secreting powerful hydrolytic enzymes (exoenzymes) while animals digest on the inside of the body. plants are autotrophs (can make their own food) while animals are heterotrophs (cannot make their own food)

how does the nutritional mode of most fungi differ from that observed in animals

animals must hunt for their food while fungi must feed on wherever they grow

what is the mycelium and how is it constructed?

interwoven mat made by hyphae; mainly large to maximize surface area

what is the main carbohydrate found in the cell walls of fungi?

chitin

what is a coenocytic fungus?

a fungus that lacks septa and hence whose body is made up of a continuous cytoplasmic mass that may contain hundreds or thousands of nuclei

what are the two major stages in the sexual life cycle of fungi?

1) plasmogamy = fusion of 2 parents cytoplasm

2) karyogamy = fusion of haploid nuclei

what is the process that restores the haploid condition before spores are produced?

meiosis

cephalization

the concentration of nerve tissue and sensory organs at the anterior end of an organism

trochophore

free-swimming larval stage of an aquatic mollusk

lophophorate

sessile animal that lacks a distinct head and possesses a feeding device called a lophophore

ecdysozoa

animal molts (undergoes ecdysis), sheds its old exoskeleton as it grows

what are the characteristics that distinguish the kingdom Animalia from others?

multicellular heterotrophic eukaryotes, store carbohydrate reserves as glycogen, lack cell wall, structural protein collagen most abundant, contain nervous muscle tissue, most produce sexually, and diploid stage usually dominates life cycle

what protists are considered the ancestors of fungi and animals?

choanoflagelates

what are some possible causes for the rapid diversification of animal body plans that arose during the cambrian explosion?

ecological causes: emergence of predator-prey relationships

geologic causes: changing O2 levels in the atmosphere

genetic causes: variations in the spatial and temporal exxpression of Hox genes

list the four key evolutionary branch points in the phylogenetic tree of animals

presence or absence of tissues, body symmetry, evolution of body cavities, and protosome-deuterostome dichotomy

what is the distinction between the parazoa and the eumetazoa?

parazoa lack true tissues and are sponges, eumetazoa have tissues and are all other animals

radial symmetry

body plan in which body parts repeat around the center of the body

bilateral symmetry

arrangement of body parts so their are distinct left and right halves that mirror each other; associated with cephalization