3.1 Mitosis And Tissues Flashcards
Describe the phases and main events of the cell life cycle?
The cell life cycle has four phases:
G1, S,G2 and mitosis.
In G1 phase, the cell growth happens and prepares for DNA replication.
In the S phase, DNA replication occurs.
During G2 phase, the cell prepares for division.
Finally, the cell undergo mitosis where the nucleus divides to form new identical daughter cells.
Explain how cells grow and divide?
Cells grow by increasing it’s size and synthesizing new component. It is then divided by the process of mitosis to produce identical daughter cells.
Describe the structure and role of the nucleus and centrosome?
The nucleus is the largest organelle usually located in the middle of cell and it is the control center of cell containing genetic material (DNA).
While centrosome is a structure which is formed by two centrioles. It’s function is to form spindle during mitosis.
Describe the structure of deoxyribo nucleic acid ( DNA).
DNA is a helical or twisted ladder shaped structure that is made up of bases, phosphate and sugar.
Describe the process of replication of DNA.
The DNA helix unicoils and hydrogen bond between the base pairs are broken. Each strand acts as a template for the creation of a new complementary DNA strand. DNA polymerase join free nucleotides with the unicoiled DNA. Thus the DNA replication occur.
Describe each of the 4 phases of mitosis?
Prophase: nuclear membrane breakdown.
Mitotic spindle forms.
Chromosomes form.
Metaphase: Chromosomes line up along the middle of the cell.
Mitotic spindle attaches to centromere.
Anaphase: Centromere spilt and chromatids are pulled apart.
Single chromosomes are pulled to either end of the cell.
Telophase: Chromosomes unravel to form loose chromatin.
Mitotic spindle breaks down.
Nuclear membrane forms.
Describe the steps in meiosis resulting in the formation of gametes?
Prophase I: Chromosomes condense and exchange genetic material.
Metaphase I: paired homologous chromosomes line up at the center of the cell.
Anaphase I: Homologous chromosomes separate and move to opposite poles.
Telophase I: Two haploid cells are formed.
Prophase II: Chromosomes condense again and new spindle apparatus forms.
Metaphase II: Chromosomes line up at the center of cell.
Anaphase II : sister chromatin separate and move to opposite poles.
Telophase II : Four haploid daughter cells are formed.
Differentiate between mitosis and meiosis.
.
Mitosis:
Produces two identical diploid daughter cells.
Occurs in somatic cells.
One round of cell division.
Maintains chromosome number.
Meiosis:
Produces four genetically diverse haploid daughter cells.
Occurs in germ cells.
Two rounds of cell division.
Reduces chromosome number by half.
Describe and classify the various types of epithelial tissue.
Epithelial tissue:
Simple squamous: Single layer of flat cells; diffusion and filtration.
Simple cuboidal: Single layer of cube-shaped cells; secretion and absorption.
Simple columnar: Single layer of tall, column-shaped cells; secretion and absorption.
Stratified squamous: Multiple layers of flat cells; protection.
Stratified cuboidal: Multiple layers of cube-shaped cells; protection and secretion.
Stratified columnar: Multiple layers of tall, column-shaped cells; protection and secretion.
Pseudostratified columnar: Single layer of cells with varying heights; secretion and propulsion.
Transitional: Multiple layers of varying cell shapes; stretchability, found in urinary system.
Identify the location and functions of the different types of epithelial tissues?
Simple squamous: Location - Air sacs of lungs, blood vessels; Function - Diffusion, filtration.
Simple cuboidal: Location - Kidney tubules, glands; Function - Secretion, absorption.
Simple columnar: Location - Intestines, stomach lining; Function - Secretion, absorption.
Stratified squamous: Location - Skin, oral cavity; Function - Protection.
Stratified cuboidal: Location - Ducts of sweat glands; Function - Protection, secretion.
Stratified columnar: Location - Pharynx, male urethra; Function - Protection, secretion.
Pseudostratified columnar: Location - Trachea, respiratory passages; Function - Secretion, propulsion.
Transitional: Location - Urinary bladder; Function - Stretchability.
Differentiate between the different types of glands and membranes
Glands:
Exocrine: Release substances onto body surfaces or into cavities via ducts.
Endocrine: Release hormones directly into the bloodstream.
Membranes:
Mucous: Lines body cavities open to exterior; secretes mucus for protection and lubrication.
Serous: Lines closed body cavities; secretes serous fluid for lubrication.
Cutaneous: Covers body surface; protection and sensation.
Synovial: Lines joint cavities; secretes synovial fluid for lubrication.
Describe the common structural elements of connective tissue?
Common structural elements of connective tissue:
Cells: Fibroblasts, adipocytes, macrophages, etc.
Extracellular matrix: Protein fibers (collagen, elastin) and ground substance (proteoglycans, glycoproteins).
Fibers: Provide strength, support, and elasticity.
Ground substance: Gel-like material that fills the space between cells and fibers.
Describe where connective tissue is found in the body and their functions.
Connective tissue is found throughout the body, including beneath the skin, around organs, within blood vessels, and in bones and cartilage. Its functions include providing structural support, connecting and binding tissues and organs together, transporting nutrients and waste, insulating and protecting organs, and participating in immune responses.
Compare the different types of muscle tissue, their structure, location and function?
Skeletal Muscle:
Structure: Long, cylindrical fibers with striations and multiple nuclei.
Location: Attached to bones by tendons.
Function: Voluntary movement, posture maintenance, heat production.
Cardiac Muscle:
Structure: Branched fibers with striations and a single nucleus.
Location: Walls of the heart.
Function: Involuntary contraction to pump blood.
Smooth Muscle:
Structure: Spindle-shaped cells with no striations and a single nucleus.
Location: Walls of internal organs, blood vessels, and airways.
Function: Involuntary movement, regulating organ functions, and controlling blood flow.
Describe the characteristics and functions of nervous tissue?
Nervous tissue:
Characteristics: Made up of neurons and glial cells; highly specialized for electrical impulse transmission.
Functions: Transmitting electrical signals (action potentials), processing and integrating sensory information, controlling and coordinating body functions, and regulating responses to stimuli.
