LECOM- HISTOLOGY EXAM 1 WITH CORRECT ANSWERS 100%

LECOM- HISTOLOGY EXAM 1 WITH CORRECT ANSWERS 100% Microtubule structure - Correct Answer Starts with a gamma tubulin ring at the negative (-) end, adds alpha/beta tubulin to the positive (+) end through the use of GTP Purpose of microtubules - Correct Answer 1. vesicular transport 2. movement of flagellum/cilia 3. separation of chromosomes in cell division 2 types of motor proteins - Correct Answer Kinesins= move towards the positive end of microtubules Dyeins= move towards the negative end of microtubules Actin - Correct Answer spontaneously assembles without a basal body, requires energy, and is very flexible Intermediate filaments - Correct Answer structural role, do not continuously reform, cell-cell and cell-matrix junctions Classes of intermediate filaments - Correct Answer Cytoplasm: keratins= all epithelial cells vimentins= fibroblasts and neurons neurofilaments= neurons Nuclear: lamins Where is the nuclear lamina located? - Correct Answer inside surface of the nuclear envelope Perinuclear space - Correct Answer located inbetween the two bilayer membranes of the nuclear envelope; is continuous with the endoplasmic reticulum What does the nuclear lamina do? - Correct Answer acts as a scaffold for the chromosomes and nuclear pores Diseases associated with defective nuclear lamina - Correct Answer Progeria (premature aging) Muscular dystrophy Telomerase - Correct Answer Adds nucleotides to the ends of the telomeres; contributes to malignancy Barr body - Correct Answer When one of two X chromosomes is repressed and remains condensed What does the nucleolus do? - Correct Answer rRNA synthesis ribosome assembly regulation of the cell cycle Nucleostemin - Correct Answer protein that regulates the cell cycle and influences differentiation static cell renewal - Correct Answer no longer dividing (neurons) stable cell renewal - Correct Answer divide as needed (smooth muscle) 4 DNA damage checkpoint locations - Correct Answer 1. beginning of G1 2. middle of S 3. beginning of G2 4. middle of G2 4 basic tissue types - Correct Answer epithelial, connective, muscle, nervous