Biology Exam Vocabulary Review

Vocabulary-style flashcards covering key biology concepts, parasites, embryology structures, genetic mechanisms, and immunological components extracted from lecture review notes.

Pronucleus

The haploid nucleus of a sperm or egg cell during fertilization, prior to fusion to form a diploid zygote.

Nerve net

The simplest and oldest type of nervous system found in animals, characteristic of Cnidarians such as jellyfish.

Primary lymphoid tissues

Organs such as the bone marrow and thymus where lymphocytes are formed and undergo maturation.

Secondary lymphoid tissues

Organs such as the spleen, lymph nodes, and MALT where mature lymphocytes encounter antigens and initiate immune responses.

Protein modification

Covalent and enzymatic alterations of proteins following protein biosynthesis, including phosphorylation, glycosylation, and ubiquitination.

Spliceosome

A complex of small nuclear RNA (snRNA) and protein subunits that removes introns from transcribed pre-mRNA.

Mandibular arch

The first pharyngeal arch involved in embryonic facial development.

Hyoid arch

The second pharyngeal arch involved in embryonic facial structure.

Sarcoptes scabiei

The Latin name for the parasitic mite that causes scabies in humans.

Cyclin-dependent kinase (CDK)

A key protein kinase that regulates progression through the cell cycle by phosphorylating target proteins.

Frameshift mutation

A genetic mutation caused by insertions or deletions of nucleotides not in multiples of three, altering the reading frame of mRNA.

Cavitation

The process during preimplantation development where fluid accumulates to form the blastocoel within the blastocyst.

Platyhelminthes

Flatworms; recognized as the oldest animal group possessing three germ layers and the oldest excretory system.

Wuchereria bancrofti

A parasitic nematode transmitted to humans via blood-sucking mosquito vectors.

Chaperones

Proteins that assist in the proper folding, assembly, and prevention of misfolding of macromolecular protein structures.

Caspases

Proteases that execute the cellular breakdown process during programmed cell death (apoptosis).

Chromosomal territory

A distinct, non-overlapping spatial region within the nucleus occupied by a specific chromosome.

Thyroid gland

An endocrine gland present across all Chordata.

Cnidarians

The oldest animal group displaying radial symmetry and possessing a nerve net.

Compaction

The stage of early embryonic development where blastomeres tightly align and adhere to form a compact morula.

Embryonic induction

The process by which one tissue or cell group influences the developmental fate of another through chemical signals.

Cytotoxic T cells

CD8+ T lymphocytes that recognize antigens presented on MHC class I molecules and kill infected cells.

Entamoeba histolytica

The Latin name of a protozoan parasite characterized by cyst and trophozoite stages.

Trichinella spiralis

A parasitic nematode acquired by humans through the ingestion of raw or undercooked meat.

p53

A crucial tumor suppressor protein that induces cell cycle arrest or apoptosis in response to DNA damage.

Ixodes ricinus

The Latin name of the tick vector responsible for transmitting Lyme disease.

Agglutination

The clumping of insoluble cells or particles caused by cross-linking antibodies binding to surface antigens.

Precipitation

The formation of an insoluble protein-antibody complex when antibodies bind to soluble antigens in solution.

Morphogen

A signaling substance that dictates tissue development patterns and spatial positioning of specialized cells based on its concentration gradient.

Cortical reaction

A secretory process altering the zona pellucida to prevent polyspermy following egg fertilization.

Heterodonty

The condition of possessing teeth of different shapes and functional types (e.g., incisors, canines, molars), characteristic of mammals.

Homodonty

The structural condition of having teeth that are all identical in shape and size.

IgG

The major class of human immunoglobulin capable of crossing the placental barrier.

IgA

The predominant class of secretory antibodies that protects mucosal membrane surfaces.

IgM

A pentameric antibody structure highly effective at initiating the classical complement activation pathway.

Chordata

A phylum characterized by a notochord, dorsal hollow nerve cord, pharyngeal slits, endostyle, and post-anal tail.

Leishmania spp.

Parasitic protozoa transmitted to mammalian hosts via blood-sucking female sandflies.

Schistosoma spp.

Trematodes (blood flukes) that reside in human mesenteric or bladder blood vessels and infect hosts by penetrating skin.

Somites

Segmented blocks of mesoderm that give rise to the vertebrae, skeletal muscle, and dermis.

Opsonization

The process of coating pathogens with molecules such as IgG or C3b to enhance phagocytic recognition and destruction.

Cohesin

A protein complex responsible for holding sister chromatids together and maintaining chromosome architecture.

Notochord

The first axial skeletal structure formed from embryonic mesoderm.

Cyclosome

Also termed the anaphase-promoting complex (APC/C); a protein complex regulating mitosis by targeting specific proteins for ubiquitin-mediated proteasomal degradation.

Protamines

Arginine-rich proteins that replace histones during spermatogenesis to achieve dense sperm DNA condensation.

Diphyllobothrium latum

A tapeworm species using crustaceans and fish as intermediate hosts before infecting humans who consume raw fish.

Ubiquitin

A small regulatory protein attached to target proteins to signal their destruction by the proteasome.

CD3

A protein complex serving as a universal co-receptor found on all T-lymphocytes.

Toxoplasma gondii

An apicomplexan parasite capable of utilizing humans as intermediate hosts, featuring tachyzoite and bradyzoite tissue stages.

Strongyloides stercoralis

A soil-transmitted parasite that infects humans through skin contact or ingestion.

NETosome

A multiprotein assembly involved in NETosis, generating extracellular DNA traps released by neutrophils.

Hardy-Weinberg Formula

An equation written as $p^2 + 2pq + q^2 = 1$, where $p$ and $q$ are allele frequencies, $p^2$ and $q^2$ represent homozygous genotype frequencies, and $2pq$ represents heterozygous genotype frequency.

Ascaris lumbricoides

A human parasitic nematode transmitted via ingestion of embryonated eggs in contaminated soil.

Ectoderm

The outermost germ layer of an embryo that gives rise to the nervous system and epidermis.

Xenograft

A tissue graft or organ transplant derived from a donor of a different species than the recipient.

Allograft

A tissue graft or organ transplant between genetically distinct individuals of the same species.

Transposon

A discrete segment of DNA that can move to different positions within a host genome.

Pseudogene

A non-functional genomic sequence that closely resembles a functional gene but contains disabling mutations.

Sperm capacitation

The physiological maturation process of spermatozoa in the female reproductive tract that enables motility and fertilization.

Robertsonian translocation

A chromosomal rearrangement caused by the fusion of the long arms of two acrocentric chromosomes.

Negative-sense RNA

Viral genomic RNA complementary to mRNA that must be transcribed into a positive-sense strand before protein translation.

Positive-sense RNA

Single-stranded viral RNA that can be directly translated into viral proteins by host cell ribosomes.

Operon

A genetic regulatory unit in prokaryotes comprising a cluster of genes transcribed under the control of a single promoter.

Wolffian duct

An embryonic ductal structure that develops into male internal reproductive organs.

Müllerian duct

An embryonic ductal structure that gives rise to the female reproductive tract.

Jacobson's organ

Also known as the vomeronasal organ; a specialized olfactory organ that detects pheromones.

Holliday junction

A four-way branched DNA structure formed during homologous genetic recombination.

Xenopsylla cheopis

The Latin name for the oriental rat flea, which serves as the principal vector for transmitting bubonic plague.

Organoid

A three-dimensional in vitro tissue culture model that replicates key structural and functional aspects of an organ.

Dermatome

A specific segment of skin supplied by cutaneous sensory nerve fibers originating from a single spinal nerve.

Incomplete penetrance

The failure of a proportion of individuals carrying a disease-causing genotype to express the associated clinical phenotype.

Enhancer

A regulatory DNA element that binds transcription factors to increase the transcription level of an associated gene.

Acrosome reaction

The release of hydrolytic enzymes from the sperm head enabling penetration through the zona pellucida.