Bio 117 Lecture Exam 3 Study Guide

A comprehensive collection of vocabulary flashcards covering Genetics, Human Anatomy and Physiology Fundamentals, the Integumentary System, the Cardiovascular System, and the Skeletal System for Bio 117 Exam 3.

Genotype

The genetic makeup of an organism, consisting of the specific alleles an individual carries for a particular trait (e.g., BB, Bb, or bb).

Phenotype

The observable physical, physiological, or biochemical traits of an organism determined by its genotype and environment.

Gene

A unit of heredity comprising a specific sequence of DNA nucleotides that codes for a functional product or trait.

Allele

An alternative or variant form of a gene located at a specific locus on a chromosome.

Locus (loci)

The specific, fixed physical position or location of a gene on a chromosome.

Punnett square

A diagrammatic grid used to calculate and predict the allele combinations and phenotypic frequencies resulting from a genetic cross.

Homozygous dominant

A genotype consisting of two identical dominant alleles for a particular gene.

Heterozygous

A genotype consisting of two different alleles for a specific gene.

Homozygous recessive

A genotype consisting of two identical recessive alleles for a particular gene.

Hemizygous

Possessing only a single copy of a gene or chromosome instead of two, such as genes located on the X chromosome in human males.

True-breeding

Organisms that consistently produce offspring with identical traits over multiple generations when self-fertilized or bred with their own kind.

Sex-linked

A pattern of inheritance for traits or disorders determined by genes located on sex chromosomes, most commonly the X chromosome.

Monohybrid cross

A genetic mating experiment between individuals that tracks the inheritance of a single specific character or trait.

Dihybrid cross

A genetic mating experiment between individuals that tracks the simultaneous inheritance of two distinct traits.

Cross-fertilization

The fusion of male and female gametes derived from two distinct individual organisms.

F1

The first filial generation; the direct hybrid offspring resulting from a parental (P) cross.

F2

The second filial generation; offspring produced through the self-fertilization or interbreeding of individuals from the $F_1$ generation.

Autosome

Any chromosome that is not a sex chromosome, representing chromosomes $1$ through $22$ in humans.

Somatic cell

Any biological cell forming the body of an organism other than reproductive cells (gametes) or germ cells.

Gamete

A haploid reproductive sex cell, such as an egg or sperm, capable of uniting with another in fertilization.

Karyotype

An organized visual display or micrograph of a complete set of metaphase chromosomes arranged in homologous pairs by size, shape, and banding pattern.

Homologous

A pair of matching chromosomes possessing the same length, centromere position, and sequence of gene loci, with one member inherited from each parent.

Incomplete Dominance

A variation in inheritance where neither allele is fully dominant, resulting in a heterozygous phenotype that appears as an intermediate blend between the two homozygous phenotypes.

Co-dominance

A variation in inheritance where both distinct alleles are fully and simultaneously expressed in the heterozygote, such as with human blood antigen alleles.

Autosomal Dominant Disorder

A genetic disorder resulting from inheriting a single copy of a dominant mutated allele located on an autosome.

Autosomal Recessive Disorder

A genetic disorder that is expressed only when an individual inherits two copies of a mutated recessive allele on an autosome.

Zygote

The single diploid cell formed immediately by the union and fusion of male and female gametic nuclei during fertilization.

Non-disjunction

The failure of homologous chromosomes or sister chromatids to separate normally during cell division, leading to an abnormal number of chromosomes in a gamete and potentially in a zygote.

Down's syndrome

A chromosomal genetic disorder usually caused by trisomy $21$ due to non-disjunction, with maternal risk increasing significantly over the age of $35$.

Anatomy

The scientific branch of biology focused on the physical structure, morphology, and spatial organization of bodily parts and organs.

Physiology

The scientific study of the biological functions, mechanisms, and physical and chemical processes that occur within living organisms.

Homeostasis

The coordinated maintenance of dynamic, stable internal conditions within an organism despite changes in the external environment.

Hormones

Chemical regulatory messengers secreted by endocrine glands directly into bodily fluids to modulate metabolic and cellular functions of distant target tissues.

Dorsal cavity

One of the two primary body cavities, situated along the posterior aspect of the body and housing the cranial and spinal subcavities.

Ventral cavity

One of the two primary body cavities, located on the anterior aspect of the trunk, enclosing the thoracic and abdominopelvic subcavities.

Fibrous connective tissue

A category of connective tissue predominantly composed of extracellular protein fibers, subdivided into loose, dense, elastic, and reticular tissues.

Loose connective tissue

A type of fibrous connective tissue with an open, airy arrangement of fibers and ground substance that cushions organs and binds epithelia to underlying tissues.

Dense connective tissue

A category of fibrous connective tissue characterized by tightly packed collagen fibers providing exceptional tensile strength in structures like tendons and ligaments.

Elastic connective tissue

A fibrous connective tissue containing abundant elastin fibers, conferring resilience and the capacity to stretch and recoil.

Reticular connective tissue

A fibrous connective tissue consisting of a delicate, mesh-like network of reticular fibers that supports lymphoid organs such as the spleen and lymph nodes.

Specialized connective tissue

Connective tissue types with distinctive structural specializations, including adipose tissue, cartilage, bone, and blood.

Adipose tissue

A specialized connective tissue composed of lipid-storing adipocytes that functions in energy storage, thermal insulation, and mechanical cushioning.

Muscle tissue

One of the four primary tissue types, composed of excitable, contractile cells specialized for producing force and bodily movement.

Nervous tissue

One of the four primary tissue types, composed of neurons and glial cells specialized for generating, processing, and propagating electrical impulses.

Epithelial tissue

One of the four primary tissue types, consisting of closely packed sheets of cells that cover body surfaces, line internal cavities, and form glands.

Endocrine gland

A ductless gland derived from epithelial tissue that secretes chemical messengers (hormones) directly into interstitial fluid and the bloodstream.

Exocrine gland

A gland derived from epithelial tissue that secretes its products through ducts onto an epithelial surface or into a body cavity.

Negative feedback

A primary homeostatic mechanism wherein a deviation from a set point triggers responses that counteract or reverse the initial stimulus.

Epidermis

The superficial, outermost layer of the skin, composed of stratified epithelial tissue that provides a protective waterproof barrier.

Dermis

The thick layer of skin positioned directly beneath the epidermis, mainly composed of connective tissue and containing vessels, nerves, follicles, and glands.

Hypodermis

The subcutaneous layer underlying the dermis, primarily composed of adipose and loose connective tissue that anchors the skin to deeper structures.

Sebaceous glands

Exocrine glands located in the skin that secrete an oily, lipid-rich substance (sebum) to lubricate and water-proof hair and skin.

Sweat glands

Exocrine glands found throughout the skin that produce and secrete sweat to assist with thermoregulation and waste excretion.

Keratin

A tough, insoluble, waterproof fibrous protein found in hair, skin, and nails that provides structural protection.

Melanocytes

Specialized pigment-producing cells residing in the epidermis that synthesize melanin to shield cells from ultraviolet radiation.

Nonmelanoma

A common group of skin cancers originating from epidermal cells other than melanocytes (such as basal cell or squamous cell carcinoma), typically less aggressive.

Melanoma

A serious, highly malignant form of skin cancer that develops from melanocytes and carries a high propensity to metastasize.

ABCDs

A diagnostic mnemonic for evaluating suspicious skin lesions for melanoma: Asymmetry, Border irregularity, Color variation, and Diameter.

Heart

The muscular organ whose coordinated rhythmic contractions pump blood through the vessels of the cardiovascular system.

Arteries

Thick-walled, elastic blood vessels that transport blood under high pressure away from the heart chambers to systemic and pulmonary tissues.

Veins

Thin-walled blood vessels containing internal one-way valves that return deoxygenated or oxygenated blood back toward the heart under low pressure.

Capillaries

Microscopic, single-endothelial-cell-thick vessels that facilitate the exchange of gases, nutrients, and waste products between the blood and tissues.

Bone marrow

The soft vascular tissue filling the interior cavities of bones, responsible for blood cell production (red marrow) or fat storage (yellow marrow).

Erthyrocytes

Red blood cells packed with iron-containing hemoglobin, primarily responsible for transporting oxygen from the lungs to bodily tissues.

Leukocytes

White blood cells of the immune system that defend the body against infectious microorganisms, foreign materials, and pathogens.

Plasma

The liquid, non-cellular extracellular matrix of blood, predominantly composed of water, dissolved proteins, electrolytes, and nutrients.

Formed elements

The cellular components of whole blood suspended within plasma, consisting of erythrocytes, leukocytes, and platelets.

Heart attack

A myocardial infarction caused by the occlusion of a coronary artery, leading to localized ischemia and necrotic damage to cardiac muscle tissue.

Hematocrit

The fractional percentage of total blood volume occupied by erythrocytes after centrifugation.

HDLs

High-density lipoproteins, commonly referred to as good cholesterol, which scavenge excess cholesterol from tissues and transport it to the liver.

LDLs

Low-density lipoproteins, commonly referred to as bad cholesterol, which deliver cholesterol to systemic cells and promote arterial plaque formation.

Aneurysm

An abnormal, localized dilation, sac, or ballooning in the weakened wall of a blood vessel.

AAA

Abdominal Aortic Aneurysm; a life-threatening, abnormal ballooning or weakness occurring in the abdominal section of the aorta.

Systole

The phase of the cardiac cycle during which ventricular muscle actively contracts to eject blood into the pulmonary trunk and aorta.

Diastole

The phase of the cardiac cycle during which ventricular muscle relaxes and ventricles expand to fill with incoming blood.

Pulse

The palpable, rhythmic mechanical expansion and recoil of an arterial wall corresponding to the ventricular contraction of the heart.

Hemostasis

The multi-step physiological sequence of vascular spasms, platelet plug formation, and blood coagulation that arrests bleeding from a damaged vessel.

SA node

The sinoatrial node; the intrinsic physiological pacemaker located in the right atrium that initiates cardiac electrical impulses.

AV node

The atrioventricular node; specialized cardiac conduction tissue that delays electrical impulses to ensure complete atrial emptying before ventricular contraction.

Purkinje fibers

Specialized conductive myocardial fibers that rapidly propagate electrical impulses through the ventricular myocardium to produce coordinated contraction.

Axial skeleton

The skeletal division aligned along the longitudinal central axis of the human body, encompassing the skull, vertebral column, ribs, and sternum.

Appendicular skeleton

The skeletal division consisting of the pectoral and pelvic girdles together with the attached bones of the upper and lower limbs.

Vertebral disc

A fibrocartilaginous pad positioned between adjacent vertebrae that absorbs shock and permits slight flexibility of the spine.

Compact bone

Dense, solid osseous tissue organized into osteons that forms the outer protective shell and shaft (diaphysis) of bones.

Spongy bone

Porous, honeycomb-like osseous tissue composed of a network of trabeculae that lightens bone and often contains red bone marrow.

Red marrow

Vascular bone marrow found within spongy bone trabeculae responsible for active blood cell formation (hematopoiesis).

Yellow marrow

Bone marrow primarily composed of adipocytes, found inside the central medullary cavity of adult long bones, serving as an energy reserve.

Osteoblasts

Bone-building cells that synthesize, secrete, and mineralize the organic extracellular matrix during bone formation and healing.

Osteocytes

Mature, non-dividing bone cells embedded within lacunae that maintain daily mineral homeostasis and sense mechanical strain.

Osteoclasts

Large, multinucleated bone-resorbing cells that secrete acids and enzymes to dissolve mineralized bone matrix during remodeling and repair.

Epiphysis

The expanded, bulbous end of a long bone, largely constructed of spongy bone capped by articular cartilage.

Diaphysis

The central elongated, tubular shaft of a long bone, comprised mainly of compact bone surrounding a medullary cavity.

Osteoporosis

A skeletal pathology marked by progressive loss of bone density and deterioration of bone tissue, which can be mitigated through weight-bearing exercise.

Joint

An articulation or functional junction formed where two or more bones, cartilage and bone, or teeth and bone meet.

Tendon

A cord of tough, dense regular fibrous connective tissue that securely anchors skeletal muscle to bone.

Ligament

A tough band of dense regular fibrous connective tissue that binds bone to bone across an articulation.

Fibrous joint

A joint category where adjacent bones are joined by dense fibrous connective tissue without a joint cavity, permitting little to no movement.

Cartilaginous joint

A joint category where bones are connected together exclusively by cartilage without a synovial cavity, permitting slight movement.

Synovial joint

A freely movable joint characterized by an enclosed, fluid-filled articular cavity lined by a synovial membrane.

Intercostals muscles

Muscle groups located within the spaces between adjacent ribs that contract to elevate and depress the ribcage during breathing.