Key Vocabulary from Introduction to Protists, Viruses, Cryptogams & Spermatophytes

Vocabulary flashcards summarizing essential terms and definitions from the lecture covering protists, viruses, bacteria, fungi, cryptogams, pteridophytes, gymnosperms and angiosperms.

Protist

A eukaryotic organism with simple body organization, lacking specialized tissues and often unicellular or colonial.

Sarcodina

A major protist group whose members move and feed by pseudopodia; includes Amoeba and Foraminifera.

Pseudopodium

Temporary cytoplasmic extension used for locomotion and feeding in amoeboid cells.

Rhizopoda

A phylum of Sarcodina containing Amoeba species that move by lobed pseudopodia.

Foraminifera

Sarcodines with rigid shells that move via protoplasmic streaming; important marine plankton.

Radiolarians

Actinopoda protists with glassy skeletons and needle-like pseudopods.

Algae

Photosynthetic protists; may be unicellular, colonial, or multicellular and include green, red and brown forms.

Rhodophyta

Red algae containing chlorophyll a and red pigment phycoerythrin; e.g., coralline algae.

Phaeophyta

Brown algae with chlorophyll a & c and the pigment fucoxanthin; includes kelp.

Chlorophyta

Green algae possessing chlorophyll a & b; e.g., Volvox.

Diatom

Unicellular photosynthetic protist with a double silica shell; belongs to Chrysophyta.

Chrysophyta

Yellow-green algae and diatoms that store carbohydrate chrysolaminarin.

Dinoflagellate

Unicellular, often photosynthetic flagellate protists (Phylum Pyrrhophyta) with two flagella; can cause red tides.

Euglenophyta

Phylum of flagellated protists (e.g., Euglena) that may be photosynthetic or heterotrophic.

Zoomastigophora

Heterotrophic, unicellular flagellates; includes parasitic Trypanosomes.

Sporozoan

Non-motile, spore-forming unicellular parasites; phylum Apicomplexa.

Apical Complex

Organelle group at apicomplexan parasite apex aiding host penetration.

Ciliophora

Phylum of heterotrophic protists with cilia and two nuclei (macro- and micronucleus); e.g., Paramecium.

Slime mould

Fungus-like protist forming spores; includes cellular (Acrasiomycota) and acellular (Myxomycota) types.

Oomycota

Water moulds with cellulose walls; many are plant pathogens.

Virus

A strand of DNA or RNA within a protein coat (capsid) lacking cellular structure and replicating only in host cells.

Capsid

Protein shell that encloses viral nucleic acid.

Nucleocapsid

Viral nucleic acid plus its surrounding capsid.

Lytic Cycle

Phage reproductive cycle culminating in host lysis and release of progeny virions.

Lysogenic Cycle

Phage life cycle in which viral genome integrates into host DNA as a prophage without immediate lysis.

Bacteriophage

Virus that infects bacteria; often abbreviated phage.

HIV

Human Immunodeficiency Virus; retrovirus that destroys CD4 T-cells leading to AIDS.

AIDS

Acquired Immunodeficiency Syndrome; immune failure disease caused by HIV.

Protozoa

Animal-like unicellular protists capable of locomotion and lacking cell walls.

Cyst

Resistant dormant stage formed by protozoa to survive adverse conditions.

Symbiosis

Close association between different organisms; includes mutualism and commensalism.

Commensalism

Symbiotic relationship where one organism benefits without affecting the other.

Mutualism

Symbiosis in which both partners benefit, e.g., flagellates in termite gut.

Parasitism

Relationship where one organism (parasite) lives at the expense of another (host).

Binary Fission

Asexual reproduction in which a parent cell divides into two equal daughter cells.

Multiple Fission

Asexual division producing many daughter cells simultaneously; seen in Plasmodium.

Budding (protozoa)

Asexual process where a mother cell releases motile daughter swarmers.

Syngamy

Fusion of two gametes to form a zygote.

Conjugation (ciliates)

Sexual process where two ciliates exchange micronuclei and separate.

Endospore

Thick-walled dormant spore formed inside certain bacteria, e.g., Bacillus.

Flagellum

Long whip-like locomotor organelle found in many protists and bacteria.

Cilium

Short hair-like projection for locomotion or feeding in ciliates.

Pellicle

Flexible protein layer beneath cell membrane of some protozoa providing protection and shape.

Virus Core

Internal nucleic-acid-protein layer between capsid and nucleic acid in some viruses.

Micronucleus

Small reproductive nucleus in ciliates.

Macronucleus

Large nucleus controlling metabolism in ciliates.

Prophage

Dormant phage DNA integrated into bacterial chromosome during lysogeny.

Mycorrhiza

Symbiotic association between fungal hyphae and plant roots enhancing nutrient uptake.

Lichen

Symbiotic association of fungus (mycobiont) with alga or cyanobacterium (phycobiont).

Bryophyte

Non-vascular land plant (mosses, liverworts, hornworts) with dominant gametophyte generation.

Gametophyte

Haploid plant generation producing gametes.

Sporophyte

Diploid plant generation producing spores via meiosis.

Prothallus

Heart-shaped gametophyte of ferns bearing antheridia and archegonia.

Archegonium

Multicellular, flask-shaped female sex organ of bryophytes and ferns housing the egg.

Antheridium

Male sex organ of bryophytes, ferns and some algae producing sperm.

Fern Frond

Large divided leaf of a fern, often bearing sporangia on underside.

Sorus

Cluster of fern sporangia on underside of frond.

Gymnosperm

Seed plant whose ovules are not enclosed in an ovary; seeds are ‘naked’ on cone scales.

Ovule

Megasporangium plus integuments that develops into a seed after fertilization.

Pollen Tube

Tubular extension of pollen grain delivering sperm to egg in seed plants.

Micropyle

Opening in ovule integuments through which pollen tube enters.

Endosperm (gymnosperm)

Haploid nutritive tissue derived from female gametophyte inside gymnosperm seed.

Cycad

Palm-like gymnosperm with large cones; produces flagellated sperm.

Conifer

Cone-bearing gymnosperm such as pine, spruce or fir.

Angiosperm

Flowering plant producing seeds enclosed within a fruit.

Monocot

Angiosperm with one cotyledon, parallel-veined leaves and floral parts in threes.

Dicot

Angiosperm with two cotyledons, net-veined leaves and floral parts in fours or fives.

Perianth

Collective term for calyx (sepals) and corolla (petals) of a flower.

Stamen

Male reproductive organ of a flower, consisting of anther and filament.

Carpel (Pistil)

Female reproductive part of a flower composed of stigma, style and ovary.

Double Fertilization

Angiosperm process where one sperm fertilizes egg (zygote) and another fuses with polar nuclei (endosperm).

Endosperm (angiosperm)

Triploid nutritive tissue formed after double fertilization in flowering plants.

Hermaphrodite Flower

Flower containing both stamens and carpels; also called perfect flower.

Seed Coat (Testa)

Protective outer covering of a seed derived from integuments.

Annual Plant

Plant completing its life cycle in one growing season.

Perennial Plant

Plant living for more than two years, often flowering annually after maturity.

Cambium

Meristematic tissue layer in stems/roots producing secondary xylem and phloem (secondary growth).

Xylem

Vascular tissue that conducts water and minerals upward in plants; comprises vessels and tracheids.

Phloem

Vascular tissue transporting sugars and organic solutes throughout plant; contains sieve tubes.

Cuticle

Waxy protective layer on epidermis reducing water loss.

Endospore (Bacteria)

Dormant resistant structure produced inside some bacteria for survival under harsh conditions.