Biological Sciences BIO102 Flashcards

Flashcards covering the characteristics, identification, classification, and biological organization of viruses, bacteria, fungi, plants, and animals based on the departmental notes.

Viruses

Simplest and smallest infectious agents ($20-200\,nm$) that are non-cellular, consisting of genetic material enclosed in a protein coat.

Capsid

The protein coat that encloses the genetic material (RNA or DNA) of a virus.

Obligate Intracellular Parasites

Organisms that require a host cell to reproduce, such as viruses.

Virions

New virus particles produced when a virus takes over a host cell’s metabolic machinery.

Latent Infections

Infections where the virus persists in a quiet state and becomes periodically active in acute episodes, such as the Herpes simplex virus.

Interferon

A secretion produced by an animal as a response to a viral infection.

Bacteria

Single-celled prokaryotic organisms ($0.5-5\,\mu m$) that have a cell wall made of peptidoglycan and reproduce by binary fission.

Gram Stain

A technique used to identify and classify bacteria based on their cell wall structure as Gram-positive or Gram-negative.

Glycocalyx

A thick and tough cell envelope in bacteria composed of mucopolysaccharides; it is also referred to as a capsule.

Pilli

Thin, filamentous, and tubular structures made of pilin protein that assist bacteria in sexual reproduction.

Fimbriae

Bristle-shaped structures extending from the bacterial cell surface involved in the attachment process to the substratum.

Mesosomes

Inward foldings of the bacterial plasma membrane that play essential roles in cellular respiration and cell division.

70s Ribosomes

The specific type of ribosomes responsible for protein synthesis found in bacterial cells.

Nucleoid

A specialized region within bacterial cells housing the genetic material, typically a single circular chromosome.

Plasmids

Small, circular DNA molecules separate from the main chromosome that carry accessory genes yielding advantageous traits.

Fungi

Eukaryotic heterotrophs with cell walls made of chitin that absorb nutrients from their environment.

Hyphae

Thread-like filaments that make up the body of a fungus; they can be septate (with pores) or aseptate (no walls).

Coenocytic Hyphae

Also known as nonseptate hyphae, these lack septa and run as a continuous, multinucleated cytoplasmic mass.

Mycelium

The mass of hyphae that forms the vegetative part of the fungus, acting like a root system to absorb nutrients.

Protoplasmic Level of Organization

The level of organization in unicellular organisms where organelles are specialized to perform life processes.

Thallus

The haploid body portion of algae that lacks tissue differentiation.

Bryophytes

Non-vascular green plants, such as mosses and liverworts, where the gametophyte is the dominant generation.

Alternation of Generation

A life cycle where a diploid sporophyte (spore plant) alternates with a haploid gametophyte (gamete plant).

Pteridophytes

Heterosporous plants where the sporophyte is the dominant generation and vascular tissues are present in roots, stems, and leaves.

Gymnosperms

Ancient seed plants that are heterosporous and bear seeds on scales arranged in cones rather than enclosed in a carpel.

Angiosperms

Flowering plants characterized by seeds enclosed in carpels, which protects the ovules from predators and environmental influences.

Protozoa

Unicellular animal-like protists classified by locomotory organelles such as pseudopodia, flagella, and cilia.

Spongocoele

The body cavity of a sponge, which is lined by collar cells known as choanocytes.

Nematocyst

A stinging organelle produced by members of the Phylum Cnidaria for defense and food capture.

Triploblastic

Animals possessing three germ layers (ectoderm, mesoderm, and endoderm), such as Platyhelminthes, Nematodes, and Annelids.

Metamerism

The condition of being divided into segments, a key innovation found in Phylum Annelida and Arthropoda.

Haemocoel

The main body cavity in Phylum Arthropoda and Phylum Mollusca where the coelom is reduced.

Metamorphosis

The process of changes in form or structure that an animal undergoes during its life cycle.

Notochord

A rod of highly packed vacuolated cells held together with a firm sheath, a characteristic feature of Phylum Chordata.