Chapter 4: From Cells to Organ Systems & Chapter 17.1-17.3: Cell Reproduction

Flashcards covering key vocabulary, definitions, and concepts from the lecture notes on Cell to Organ Systems and Cell Reproduction.

Unicellular organisms

Consist of just one cell and depend on their immediate external environment.

Multicellular organisms

Consist of many cells, are larger in size, able to seek out or maintain a favorable external environment, and have specialized cells that contribute to the well-being of other cells.

Tissues

Groups of specialized cells that are similar in structure and perform a common function.

Primary tissues

The four main types of tissues: Epithelial, Connective, Muscle, and Nervous tissues.

Epithelial tissue

Organized as sheets of cells, one or more layers, attached to a basement membrane, avascular, covers exterior body surfaces, and lines internal cavities and organs.

Function of Epithelium

Physical protection, maintains integrity, regulates nutrient absorption and ion transport, provides sensation, and produces specialized secretions.

Glands

Epithelial tissues specialized to synthesize and secrete a product.

Simple epithelial tissue

A single-layer of epithelial cells adapted for diffusion across cell barriers, lining glands, and respiratory, digestive, and reproductive systems.

Stratified epithelial tissue

Multiple-layers of epithelial cells that provide protection, such as in the skin surface.

Squamous cells

Flattened epithelial cells that form the outer surface of the skin and line blood vessels, lungs, mouth, throat, and vagina.

Cuboidal cells

Cube-shaped epithelial cells that form the lining of kidney tubules and glandular tissue.

Columnar cells

Column-shaped (tall, rectangular) epithelial cells that line the digestive tract, certain reproductive organs, and the larynx; may include goblet cells.

Goblet cells

Specialized cells within columnar epithelium that secrete mucus.

Basement membrane

A noncellular layer directly beneath epithelial tissue, composed of proteins, that provides structural support and attaches the epithelial layer to underlying connective tissue.

Cell junctions

Structures that hold adjacent cells together.

Tight junctions

Cell junctions that seal plasma membranes tightly together, found in the digestive tract lining and bladder lining.

Adhesion junctions (spot desmosomes)

Cell junctions that permit some movement between cells, allowing tissues like skin to stretch and bend.

Gap junctions

Protein channels that enable the movement of materials between adjacent cells, found in the liver and heart.

Connective tissue

Tissue that supports softer organs, connects parts of the body, stores fat, produces blood cells, and contains cells embedded in a nonliving matrix.

Matrix (connective tissue)

The nonliving component within connective tissue that provides its strength.

Fibrous connective tissue

Connective tissue that provides strength and elasticity, containing fibers and cells embedded in a gel-like ground substance.

Ground substance (fibrous CT)

The intercellular material in fibrous connective tissue that gives it its characteristics.

Fibroblasts

Cells in fibrous connective tissue that produce and secrete proteins forming fibers like collagen and elastin.

Collagen fibers

The most abundant, very strong but flexible fibers found in fibrous connective tissue, important in ligaments, tendons, and bones.

Reticular fibers

Interwoven immature collagen fibers that support nerves, blood, and lymphatic vessels.

Elastic fibers

Branched and wavy fibers that stretch and recoil, found in respiratory, vascular, urinary, and skin systems.

Loose connective tissue (areolar connective tissue)

A type of fibrous connective tissue that surrounds internal organs, muscles, and blood vessels, with few collagen and elastic fibers and no specific pattern.

Dense connective tissue

A type of fibrous connective tissue that forms tendons, ligaments, and deeper layers of skin, with many collagen fibers in parallel arrangement.

Elastic connective tissue

A type of fibrous connective tissue that surrounds hollow organs like the stomach and bladder that change shape or size regularly, containing many elastic fibers.

Reticular connective tissue

A type of fibrous connective tissue that makes up the internal framework of soft organs like the liver and the lymphatic system.

Specialized connective tissues

Unique types of connective tissue that serve specific functions, including cartilage, bone, blood, and adipose tissue.

Cartilage

A specialized connective tissue that is a transitional tissue from which bone develops, maintains the shape of the nose and ears, and protects and cushions joints and vertebrae; it is avascular.

Bone

A specialized connective tissue that forms the skeleton, has a matrix composed of calcium phosphate, and contains numerous blood vessels.

Blood

A specialized connective tissue with a fluid matrix of plasma, red blood cells, white blood cells, and platelets, primarily functioning to transport materials.

Plasma

The fluid matrix component of blood cells.

Red blood cells

Blood cells that transport oxygen and carry away wastes.

White blood cells

Blood cells that defend the body as part of immune defenses.

Platelets

Blood cells that function in blood clotting.

Adipose tissue

A specialized connective tissue composed of fat cells (adipocytes) that stores fat, insulates, protects, and provides energy storage.

Adipocytes

Fat cells that store fat in vacuoles within adipose tissue.

Muscle tissue

Tissue composed of muscle cells (muscle fibers) that shorten (contract) to produce movement.

Skeletal muscle

Muscle tissue that connects to tendons and attaches to bone, composed of thousands of individual muscle fibers with multiple nuclei, is voluntary, and activated by nerves.

Cardiac muscle

Muscle tissue located only in the heart, composed of shorter, blunt-ended cells with one nucleus, contains gap junctions for coordinated contraction, and is involuntary.

Smooth muscle

Muscle tissue that surrounds hollow organs and tubes (e.g., blood vessels, digestive tract, uterus, bladder), composed of slim, tapered cells with one nucleus, and is involuntary.

Nervous tissues

A rapid communication network including the brain, spinal cord, and nerves throughout the body.

Neuron

A specialized nervous system cell that generates and transmits electrical impulses.

Glial cells

Nervous system cells that surround and protect neurons and provide nutrients to them.

Organs

Structures composed of two or more tissue types joined together that perform specific functions.

Organ systems

Groups of organs that serve a broad function important to the survival of an individual or the species.

Anterior cavity

The front body cavity, divided by the diaphragm into the thoracic cavity (containing pleural and pericardial cavities) and the abdominal cavity (including the pelvic cavity).

Posterior cavity

The back body cavity, including the cranial cavity and the spinal cavity.

Tissue membranes

Serous membranes that line body cavities.

Serous membranes

Tissue membranes that line and lubricate internal body cavities, reducing friction between organs.

Mucous membranes

Tissue membranes that line airways, the digestive tract, and the reproductive tract, lubricating surfaces and capturing debris.

Synovial membranes

Tissue membranes that line spaces in movable joints.

Cutaneous membrane

Tissue membrane that forms the outer covering of the body (skin).

Sagittal plane

A body plane that divides the body into right and left halves (midsagittal for equal halves).

Frontal (coronal) plane

A body plane that divides the body into anterior and posterior halves.

Transverse plane

A body plane that divides the body into superior and inferior parts.

Oblique plane

A less standardized body plane cut that is at an angle.

Cell differentiation

The process by which cells become different from each other and from the parent cell, becoming more specialized.

Cell cycle

The sequence of events in the life of a cell from its creation to its division, including interphase and the mitotic phase.

Interphase

The long growth period between cell divisions, consisting of G1 (primary growth), S (DNA synthesis), and G2 (final growth) phases.

Mitotic phase

The cell division phase, including nuclear division (mitosis) and cytoplasmic division (cytokinesis).

Mitosis

Nuclear division during which duplicated DNA is distributed between two daughter nuclei, resulting in identical daughter cells.

Cytokinesis

The process where the cytoplasm divides, forming two new daughter cells.

Chromosomes

Structures composed of DNA and histones, where human DNA is organized into 46 separate units.

Histones

Proteins that DNA wraps around to form chromosomes.

Chromatin

Loose and diffuse DNA found throughout most of the cell cycle.

Sister chromatids

Two identical copies of a chromosome joined together by a centromere, visible during mitosis.

Centromere

The constricted region where two sister chromatids are joined.

Gene

A short segment of DNA that contains the code, or recipe, for a protein.

DNA replication

The process of copying the cell’s DNA prior to cell division, making exact copies of all chromosomes.

Transcription

The process of creating a coded message (working copy) of a single gene in RNA (messenger RNA) that can be carried out of the nucleus.

Translation

The process of using the mRNA coded message to assemble amino acids into proteins useful to the cell.

DNA polymerase

The major enzyme responsible for DNA replication.

Mutations

Alterations in the nucleotide sequence of DNA.

Somatic cell mutations

DNA alterations in non-gamete cells that may affect tissue function or cause cancer but are not passed on to descendants.

Gamete mutation

A DNA alteration in reproductive cells that is passed on to future generations.

DNA repair enzymes

Enzymes that recognize and cut out errors in DNA sequences, replacing the damaged section and rejoining the DNA backbone.

Messenger RNA (mRNA)

An RNA molecule that carries the genetic message from DNA to the ribosomes for protein synthesis.

Ribosomes

The cellular sites where translation (protein synthesis) occurs.

RNA polymerase

An enzyme that assists in copying the DNA nucleotide sequence into a polymer of RNA nucleotides during transcription.

Primary transcript (RNA)

The initial RNA molecule made during transcription before any processing.

RNA processing

The enzymatic modification of pre-mRNA, including the editing out of introns and splicing of exons, before the genetic message is passed to the cytoplasm.

Introns

Non-coding regions within a primary RNA transcript that are edited out by catalytic RNAs called ribozymes.

Ribozymes

Catalytic RNAs that remove introns from pre-mRNA.

Exons

Coding regions within a primary RNA transcript that carry genetic information and are spliced together to form messenger RNA.

Codon

A sequence of three mRNA bases that codes for a specific amino acid.

Start codon (AUG)

A specific mRNA codon (methionine) that signals the beginning of all genes and initiates translation.

Stop signals

Three specific mRNA triplets that signal the end of translation.

Transfer RNAs (tRNA)

RNA molecules that escort specific amino acids to the ribosome, matching their anticodons with complementary codons on mRNA.

Anticodons

Sequences of three bases on a tRNA molecule that pair with complementary codons on mRNA during translation.

Ribosomal RNA (rRNA)

A type of RNA that, along with proteins, makes up the structure of ribosomes.

Diploid (2n)

A cell that has two sets of chromosomes, one inherited from the mother and one from the father.

Meiosis

A cell reproduction process that generates haploid gametes (sperm and egg cells) that are genetically different from the parent cell.

Haploid (n)

A cell that has only one set of chromosomes.

Prophase (mitosis)

The first phase of mitosis where the mitotic spindle forms, centrioles migrate to cell poles, chromatin condenses into visible chromosomes, and the nuclear membrane dissolves.

Metaphase (mitosis)

The second phase of mitosis where duplicated chromosomes (each with two sister chromatids) form a single line at the equator of the cell between the centriole poles.

Anaphase (mitosis)

The third phase of mitosis where duplicate chromosomes (sister chromatids) separate and daughter chromosomes are pulled toward opposite poles by microtubules.