MCQ cytology 1st colloqium

general classification of cell organelles

cell membrane (plasmalema, plasma membrane)

nucleus

cytoplasm

cell membranes

• glycocalyx

• solitary membrane

• submembraneous protein-filament complex

• intercellular contacts

• microvilli

cytoplasms

• matrix

  • cytosol/hyaloplasm

• general organelles

  • smooth ER

  • rough ER

  • ribosomes

  • polyribosomes

  • golgi complex

  • mitochondria

  • cytocentre

  • lysosomes

  • peroxisomes

  • coated pits

  • microtubules

  • microfilaments

  • coated vesicles

• specialised organelles

  • myofibrils (actin, myosin)

  • tonofibril

  • neurofibril

  • cilia

  • flagella

  • secretory granules

• metabolic inclusions

  • protein granules

  • glycogen

  • lipid droplets

  • pigments

  • crystals

nucleus

• nuclear membrane

  • outer membrane

  • perinuclear space

  • inner membrane

  • nuclear pores

• nuclear matrix

• chromatin

  • chromatin in interphase(euchromatin/heterochromatin)

  • chromatin in mitosis

• nucleolus

  • granular component (nucleolonema, pars granulosa)

  • fibrilar component (pars filamentosa)

  • amorphous components (pars amorpha)

what is receptor mediated endocytosis?

process of accepting substances after recognising them and linking them to their specific membrane receptors

what does the clathrin protein participate in?

coated vesicles

what is exocytosis?

process of releasing secretory granules through the cell membrane

glycocalix

a glycoprotein coat located on top of the plasmalemma and attached to it

what are cytoplasmic inclusions and are they obligatory?

Definition: These are non-living substances found within the cytoplasm of a cell, often serving as storage for nutrients, pigments, or waste products. They can vary in size and composition, including glycogen granules, lipid droplets, and crystals.

Obligatory? No, they are not obligatory structures; their presence depends on the cell type and its metabolic needs.

what is meant by obligatory cell?

Definition: A type of cell that is essential for the functioning of a specific tissue or organ. If removed or absent, it leads to dysfunction or failure of that tissue or organ

• involved in processes like metabolism, signaling, or structural support

• presence is mandatory for maintaining homeostasis and overall health within the organism.

can you see cell matrix (cytosol) with a light microscope?

Answer:No, the cell matrix (cytosol) is typically not visible with a light microscope due to its transparent nature and low contrast.

cytosol require electron microscopy for better resolution.

what do mitochondria under a light microscope appear as?

tender granules or filaments

what are nissl bodies?

light microscopic image ofof rough endoplasmic reticulum and ribosomes

how are ciliums built?

assembly of microtubules, specifically a 9+2 arrangement of tubulin proteins

do coated vesicles participate in intracellular transport processes?

yes

what is euchromatin?

active form of chromatin in the nucleus

what are microtubules apart of?

cytoskeleton

what does plasma membrane consist of?

lipid bilayer and integral proteins

pinocytosis

uptake of fluid material by cells

which contact does the intercellular space disappear?

Tight Junctions (Zonula Occludens): Specialized structures in epithelial tissues that enable cells to adhere closely, eliminating gaps between their membranes. They play a crucial role in maintaining tissue integrity, regulating the passage of substances, and facilitating signaling and communication.

what are conexones structural components of?

gap junction (nexus)

golgi apparatus stain

silver impregnation AgNO3

what is formation of new mitochondria associated with?

their own budding or simple division

what process is associated with the rough ER?

protein synthesis

what do coated vesicles participate in?

intracellular transport processes

what do lysosomes consist of?

single membrane and hydrolytic enzymes

where is sex chromatin (Barr body) seen in?

female somatic cells

feulgen stain for?

DNA

what do histone proteins take part in?

formation of DNA molecule

interphase nucleus of young, functional activity cells is:

large, pale stained with prominent nucleolus

where do chromosomes move in metaphase?

move to centre of cell equatorial plane

what do mitotic spindle fibres consist of?

microtubules

stain for lipid

Sudan III + H

karyorexis

Definition: A type of cell death characterized by the fragmentation of the nucleus into small pieces

apocrine secretion characterised

Definition: A type of secretion that involves the release of the apical portion of the cell's cytoplasm along with the secretory product.

apoptosis

programmed cell death

fiber of the division spindle are

microtubules

nucleolus

related to formation of subunits of the ribosomes (rRNA)

characteristic of the enzyme acid phosphatase

lysosomes

what do the integral proteins of the plasma membrane interact with?

peripheral proteins

components of the cytoskeleton

glycocalix description

• is a polysaccharide layer

• takes part in cell adhesion

• takes part in cell cooperation

what is nexus?

• built of connexones

• consist of protein channels for transport of small molecules and ions between the cells

what is the basophilia of the cell cytoplasm due to?

• presence of abundant rough ER

• numerous ribosomes

nuclear pores description

• selective transport of substances across the nuclear envelope

• formed at sites where the inner and outer membranes of the nuclear envelope are joined

nucleolus

• build part of chromosomes 13,14,15,21 and 22

• where ribosome formed

• component of nucleus

main function of smooth ER

• synthesis of lipids and steroid hormones

• synthesis of glycogen and mucus

• intracellular transport

dyctysome description

• component of the golgi apparatus

• flattened cisternae with outer forming and inner secreting surfaces

• release secretory granules from the outer surface

mitochondria specific features

• posses own genetic apparatus

• formation of new mitochondria through own budding or simple division

• take part in ATP synthesis

common features of mitochondria and peroxysome

• contain matrix with numerous enzymes

• general membrane cell organelles

lysosome features

• intracellular digestion

• contain hydrolytic enzymes

• related to processes of cell aging and death

peroxysome specific features

• contain oxidative enzymes

• contain matrix with crystalloid

microtubule specific

• sustain cell shape

• intracellular transport of molecules and organelles

• participate in formation of spindle fibres during the mitosis

how is mitochondria visualised?

• iron-hematoxylin

• Altmann method acid fucsin

typical for nuclear membrane

• double layered

• continous with the rough ER

• nuclear pores

based on their function the plasma membrane proteins are classified as

• receptors

• transport

• connecting

• enzymes

• transductive

what are the types of cell junction (intercellular contacts)?

Tight Junctions (zonula occludens) - Seal adjacent cells, preventing leakage of molecules between them.

Desmosomes (zonula adherens/macula adherens) - Anchor intermediate filaments, offering strong adhesion under stress.

Gap Junctions (nexus) - Allow direct communication between cells through channels

Zipper interlocking (interdigitations)

what does an electron microscope image of nucleolus show?

• granular part (pars granulosa)

• fibrous part (pars fibrosa)

main changes in nucleus and cytoplasm during prophase

• nucleolus disappear

• nuclear envelope disappear

• mitotic spindle fibres form

• chromosomes coild and condense becoming visible (spirem figure)

general membrane cell organelles

• endoplasmic reticulum

• golgi apparatus

• mitochondria

• lysosome

• peroxisome

• coated vesicles

electron microscope of Golgi complex

• cisternae

• microvesicles

• vacuoles

main components of the cytoskeleton

• microtubules

• microfilaments

cell inclusions are:

• glycogen granules

• lipid droplets

• pigments

• crystals

what are the light microscopic changed in ageing cell?

• pyknosis

• karyorexis

• karyolysis

what are the types of exocrine secretions?

• merocrine

• apocrine

• holocrine

what are some specialised cells?

• myofibril

• tonofibril

• neurofibril

• cilia

• flagella

• secretory granules

what is the organelle when by light microscope obs of spinal ganglion stained with AgNO3 and reticular network is seen near the nucleus?

Golgi apparatus

electron microscopy of bowl-like complex with parallel cisternae with vesicles and vacuoles

Golgi complex

what is the EM of cylindrical structure at right angles composed of 9 sets of 3 microtubules?

centrioles

light microscope seen Sudan III + H staining orange droplets with blue nuclei are seen

lipid inclusions

what is the stage in mitosis where the chromosomes are localised in the opposite poles of teh spindle fibres

anaphase

9×2 + 2 arrangement of microtubules can be seen with EM what is the organelle?

cilia

oval with cristae and two membranes seen with EM

mitochondria