BSCI 160 exam 2 New

Protists

Diverse group of mostly unicellular eukaryotes that are not plants

Monophyletic group

A group consisting of a common ancestor and all of its descendants

Contractile vacuole

Organelle in some protists that regulates water balance by expelling excess water

Cilia

Short hair-like structures made of microtubules used for locomotion and feeding in some protists

Flagella

Long whip-like structures with a 9+2 microtubule arrangement used for cell movement

Pseudopodia

Temporary cytoplasmic extensions used for movement and feeding

Fungi

Eukaryotic organisms that are heterotrophic

Chitin

A polysaccharide that makes up fungal cell walls and arthropod exoskeletons

Dikaryotic cell

A fungal cell containing two genetically distinct nuclei

Spores

Reproductive cells capable of developing into a new organism

Archaea

Domain of life distinct from Bacteria and Eukarya with unique membrane lipids and genetics

Branched phospholipids

Membrane lipids characteristic of archaea that enhance stability in extreme environments

Synapomorphy

A shared derived trait used to identify a clade

Chordates

Animals that possess a notochord

Notochord

Flexible rod that provides support in chordate embryos

Dorsal nerve cord

Hollow nerve cord located on the dorsal side of chordates

Arthropods

Invertebrate animals with segmented bodies

Ecdysozoans

Animals that grow by molting their exoskeleton

Molting (ecdysis)

Periodic shedding of the exoskeleton to allow growth

Stomata

Pores in plant tissues that regulate gas exchange and water loss

Bryophytes (mosses)

Nonvascular land plants that were among the first to evolve stomata

Basal metabolic rate

The rate of energy use by an organism at rest

Homeotherm

An organism that maintains a constant internal body temperature

Ribosomal RNA (rRNA)

RNA component of ribosomes used to infer evolutionary relationships due to slow evolutionary change

Lateral gene transfer

Movement of genetic material between organisms other than by vertical inheritance

RNA world hypothesis

Idea that early life used RNA as both genetic material and catalyst

Phospholipid bilayer

Double layer of lipids that forms cell membranes

Milankovitch cycles

Periodic changes in Earth’s orbit and tilt that affect climate

Obligate aerobe

An organism that requires oxygen for survival

Amphibians

Ectothermic vertebrates that typically undergo metamorphosis and rely on water for reproduction

Metamorphosis

Developmental transition from larval to adult form

Water vascular system

Hydraulic system in echinoderms used for locomotion

Endosymbiosis

Theory that mitochondria and chloroplasts originated from free-living bacteria

Cytoskeleton

Network of protein filaments that provides structure and enables movement in eukaryotic cells

Hominids

Group including modern humans and their extinct relatives

Savanna hypothesis

Idea that early human evolution occurred in African grasslands

Angiosperms

Flowering plants with seeds enclosed in fruits

Endosperm (3N)

Triploid nutritive tissue formed during double fertilization in angiosperms

Double fertilization

Process in angiosperms producing a zygote and endosperm

Bacteriophages

Viruses that infect bacteria

Phage therapy

Use of bacteriophages to treat bacterial infections

Cuticle

Waxy layer on plant surfaces that reduces water loss

Vascular tissue (xylem)

Plant tissue that transports water and minerals

Deuterostomes

Animals in which the blastopore becomes the anus during development

Protostomes

Animals in which the blastopore becomes the mouth

Spiral cleavage

Pattern of embryonic cell division used to infer evolutionary relationships

Lophotrochozoans

Protostome clade that often exhibits spiral cleavage

Lichens

Symbiotic association between a fungus and an alga or cyanobacterium

Soredia

Asexual reproductive structures of lichens

Sporangium

Structure in plants where spores are produced

Meiosis

Cell division that produces haploid gametes or spores

Bilaterians

Animals with bilateral symmetry and three tissue layers

Cnidarians

Diploblastic animals considered the sister group to bilaterians

Basidiomycetes

Fungi that produce spores on basidia and form dikaryotic fruiting bodies

Megaphylls

Leaves with complex vein systems that evolved from branched stems

Gill arches

Structures in early vertebrates that evolved into jaws and other features

Jaws

Key vertebrate innovation derived from gill arches

Microgametophyte

Male gametophyte in seed plants

Mycorrhizae

Mutualistic association between plant roots and fungi

Mollusks

Invertebrates with a mantle

Radula

Rasping feeding structure found in most mollusks

Platyhelminthes

Flatworms that are acoelomate and often parasitic

Cephalization

Concentration of sensory organs at the anterior end

Glaucophytes

Algae with chloroplasts retaining cyanobacterial traits

Primary endosymbiosis

Origin of plastids from engulfed cyanobacteria

Segmentation

Repetition of body units seen in multiple animal lineages

Heterospory

Production of two types of spores

Alveolates

Protist clade characterized by alveoli beneath the cell membrane

Alveoli

Flattened sacs that provide structural support in alveolates

Charophytes

Green algae most closely related to land plants

Holometabolous insects

Insects with complete metamorphosis including larval