LAB 3 - DNA Replication, Mitosis and Epithelial Tissue

Terms Only

What are the steps to the cell cycle?

What happens in each step?

1) Interphase: normal life with preparations for cellular division 2) Mitosis: Division of the nucleus into two daughter cells 3) Cytokinesis: division of cytoplasm

When do Mitosis and Cytokinesis overlap?

Last 2 phases of mitosis

What are the phases of Interphase?

What happens in each phase?

G1: Cell growth, duplication of organelles, replication of centrioles

Synthesis: all 46 DNA strands are replicated

G2: Centrole replication is complete, along with enzymes and other needed structures

Describe the composition of the replicated DNA made in S Phase

Made of 2 sister chromatids attached by centomere

What enzymes are needed for DNA replication?

What are their primary functions?

DNA Helicase: unwinds and separates DNA strands

DNA polymerase: assembles new strands of DNA

What are the steps of DNA replication?

1) DNA unwinds via DNA helicase

2) Break apart H Bonds between the two parental strands

3) Deoxyribonucleotides form covalent bonds with the exposed bases of the parental strand via DNA polymerase

4) New DNA is coiled back into helix structure

What are the phases of Mitosis?

Prophase

Metaphase

Anaphase

Telophase

What happens during Prophase?

Chromatin condenses into a chromosome

Centrioles push apart with spindle fibers starting to extend

No more nuclear envelope

What happens during Metaphase?

More spindle fibers Chromosomes moved to the equatorial plate

What happens during Anaphase?

Spindle fibers pull apart sister chromatids

Cytokinesis begins

What happens during Telephase?

Chromosomes turn back into chromatin

Nucleolus and envelope reassemble

Spindle fibers break down

What is the visual marker for the continuation of Cytokinesis?

Cleavage furrow

Which tissue modification means the increase in cell size?

Hypertrophy

Which tissue modification means the increase in number of cells?

Hyperplasia

Which tissue modification means the loss of cell size AND number?

Atrophy

Which tissue modification means abnormal tissue development?

Dysplasia

Which tissue modification means programmed cell death?

Apoptosis

Which tissue modification means tissue death (unplanned)?

Necrosis

What are the primary characteristics of Epithelial Tissue?

Avascular - lack blood vessels

Highly innervate- lots of sensory receptors

High Regenerative

How are Epithelial tissue classifided?

By number of layers: simple, stratified, pseudostratisfed

By shape of cells: Squamous, Cuboidal, Columnar, Transitional

Shape and Location of Simple Squamous cells

S: single layer, flat cells with nucleus bulging at center

L: Lining blood and lymphatic vessels and lining of serous membranes

Shape and Location of Simple Cuboidal cells

S: single layer, cube shape, nucleus round and centered

L: glandular tissue, thyroid, kidney tubles

Shape and Location of Ciliated and Nonciliated Simple Columnar Cells

S: single layer of tall cells, oval nucleus at bottom of cell

L: w/o cilia -lining of stomach, small and large intestines

w/ Uterine tubles and smaller airways

What cells have goblet cells withing them?

Nonciliated Simple Columnar cells

Shape and Location of Pseduostratified Columnar cells

S: single layer of tall cells with nucleus withing any region of cell

L w/ cilia large airways

w/o cilia male urethra

Shape and Location of Keratinized Stratified Squamous cell

S: cells at apical surface, dead not nucleus

L: outer layer of skin

Shape and Location of Nonkeratinized Stratified Squamous cells

S: Multi-layer, cube shape, centered nucleus

L: Lining of the mouth, throat, esophagus, and vaginal canal

Shape and Location of Transitional Cells

S: Multi Layer, relaxed = cuboidal and round, Distended = squamous

L: Only found in Bladder