Lecture Exam #1 Study Guide - Human Organism, Cell Biology, Genetics, & Tissues

Vocabulary practice flashcards generated from the Lecture Exam #1 Study Guide covering Chapter 1 (The Human Organism), Chapter 3 (Cell Biology), Chapter 29 (Genetics), and Chapter 4 (Tissues).

Anatomy

The science of the structure of an organism.

Physiology

The science of the function of an organism.

Cell

The simplest body structure considered to be alive.

Hierarchy of Complexity

The structural levels of organization in the human body, progressing from chemical components up to the whole organism.

Homeostasis

The ability of an organism to maintain a stable internal environment.

Set-Point

The physiological target value or average state around which a controlled variable fluctuates in homeostasis.

Negative Feedback Loop

A primary homeostatic mechanism that reverses or opposes a change in a controlled condition to restore stability.

Positive Feedback Loop

A self-amplifying homeostatic mechanism in which a change leads to continuous amplification in the same direction; more likely to cause disease and death if unchecked.

Anatomical Position

The standard reference position where the body stands erect, facing forward, with arms at the sides and palms facing forward.

Anatomical Planes

Three imaginary flat surfaces (sagittal, frontal/coronal, and transverse/horizontal) used to cut and separate the body into sections.

Plasma Membrane

The outer boundary of the cell that regulates the movement of substances into and out of the cytoplasm.

Nucleus

The primary cellular organelle containing genetic material (DNA) that directs cellular functions.

Cytoplasm

The cellular contents located between the plasma membrane and the nucleus, containing cytosol and organelles.

Extracellular Fluid

The fluid environment located outside of the plasma membrane.

Intracellular Fluid

The fluid environment located inside the plasma membrane (cytosol).

Phospholipid Bilayer

The primary structural component of the plasma membrane, arranged with hydrophilic heads facing the exterior/interior aqueous environments and hydrophobic tails facing inward.

Diffusion Rate

The speed at which particles spread down their concentration gradient, influenced by factors such as molecular weight (smaller molecular weight yields a faster diffusion rate).

Passive Transport

The movement of substances across a biological membrane down a concentration gradient without requiring cellular energy (ATP).

Active Transport

The movement of substances across a biological membrane against a concentration gradient, requiring cellular energy (ATP).

Osmosis

The net movement or diffusion of water across a selectively permeable membrane.

Isotonic Environment

A solution with an equal solute concentration compared to the cell interior, resulting in no net movement of water or change in red blood cell volume.

Hypotonic Environment

A solution with a lower solute concentration than the cell interior, causing water to enter red blood cells, making them swell and potentially burst.

Hypertonic Environment

A solution with a higher solute concentration than the cell interior, causing water to leave red blood cells, leading to cellular shrinkage (crenation).

Transcription

The step during gene expression where a complementary mRNA sequence is synthesized from a DNA template in the nucleus.

Translation

The step during gene expression where mRNA code is read by ribosomes and tRNA to assemble amino acids into polypeptides (proteins).

Law of Complementary Base Pairs

The rule governing nitrogenous base pairing in nucleic acids (Adenine pairs with Thymine/Uracil, Cytosine pairs with Guanine).

Codon

A three-nucleotide sequence on an mRNA molecule that specifies a particular amino acid during translation.

Anticodon

A three-nucleotide sequence on a tRNA molecule that complements and binds to a specific mRNA codon.

Interphase

The period of the cell cycle between divisions, consisting of three phases (G1, S, and G2) involved in cell growth and DNA replication.

Mitosis

Nuclear cell division producing two genetically identical diploid daughter somatic cells.

Meiosis

Specialized cell division producing four genetically unique haploid gamete cells (sperm/egg).

Genotype

The specific genetic makeup or pair of alleles present for a trait in an organism.

Phenotype

The observable physical or functional traits resulting from genetic expression and environmental interaction.

Homozygous

An individual having two identical alleles for a given gene.

Heterozygous

An individual having two different alleles for a given gene.

Somatic Cell

Any body cell other than a reproductive cell, containing a complete diploid set of chromosomes ($2n$).

Gamete Cell

A reproductive sex cell (sperm or egg) containing a single haploid set of chromosomes ($n$).

Allele

An alternative or variant form of a specific gene located at a given chromosomal position.

Locus

The exact physical location of a gene on a chromosome.

Karyotyping

A laboratory method of displaying and examining the full chromosome set of an individual, performed during metaphase of mitosis.

Sex-Linked Recessive Disorder

A genetic disease carried on a sex chromosome (typically the X chromosome) requiring recessive allele inheritance to be expressed.

Complete Dominance

A pattern of gene expression where the dominant allele completely masks the phenotype of the recessive allele in heterozygous individuals.

Codominance

A pattern of gene inheritance where both alleles in a heterozygote are fully and simultaneously expressed without blending.

Incomplete Dominance

A pattern of gene inheritance where a heterozygous phenotype is an intermediate blend between the two homozygous phenotypes.

Biopsy

The removal and micro-examination of tissue from a living subject for medical diagnosis.

Autopsy

The postmortem dissection and examination of body tissues to establish the cause of death.

Apical Surface

The free, unattached upper surface of epithelial cells that faces an open body cavity, lumen, or external environment.

Basal Surface

The attached lower surface of epithelial cells anchored to the underlying basement membrane.

Simple Epithelium

Epithelial tissue composed of a single layer of cells, primarily function-specialized for absorption, secretion, and filtration.

Stratified Epithelium

Epithelial tissue composed of multiple layers of cells, primarily function-specialized for protection against physical wear and tear.

Endocrine Glands

Ductless glands that secrete hormones directly into surrounding blood vessels and systemic circulation.

Exocrine Glands

Ducted glands that release non-hormonal secretions onto an internal or external epithelial surface.

Merocrine Glands

Exocrine glands that release their secretions via exocytosis without losing cellular cytoplasm.

Apocrine Glands

Exocrine glands that release secretions by pinching off the apical portion of the secretory cell cytoplasm.

Holocrine Glands

Exocrine glands whose secretory cells disintegrate completely to release their product.

Fibroblasts

Abundant cells in connective tissue that synthesize and secrete protein fibers and ground substance into the extracellular matrix.

Macrophages

Phagocytic cells in connective tissue that engulf foreign pathogens, dead cells, and cellular debris.

Mast Cells

Connective tissue cells involved in inflammation and allergic response that secrete chemical signals like histamine and heparin.

Adipocytes

Fat-storing cells in connective tissue specialized for lipid storage, insulation, and protective cushioning.

Extracellular Matrix

The non-cellular material surrounding connective tissue cells, composed of protein fibers and ground substance.