Flashcards
Cells and Tissues
Flashcards do conjunto (33)
- 1What is a cell?The smallest structural and functional unit of an organism.
- 2What is the structure of the plasma membrane?The plasma membrane consists of a lipid bilayer, 2 layers of phospholipids. These phospholipids have a hydrophilic head and a hydrophobic tail. This lipid bilayer has selective permeability, therefore it can choose what it does and does not let into the cell.
- 3What is the function of the plasma membrane?-Ensure cell structural integrity
-Regulates entry & exit of substances
-Maintains chemical composition of cytoplasm & extracellular fluid
-Participates in cellular communication
-Forms a cellular identification system
-Participates in some enzymatic activties - 4What is the difference between a prokaryote and a eukaryote>Prokaryote: smaller, no nucleus, no membrane-bound organelle, no cytoplasm, single circular DNA, divides by binary fission
Eukaryote: larger, has nucleus, has membrane-bound organelle, has chromosomes, divides by mitosis - 5What is the structure and function of the nucleus?Most prominent feature of cell
Structure: tightly condensed chromatin. (tightly packed=heterochromatin-inactive cells. loosely packed=euchromatin-active cells)
Function: cellular regulation-holds DNA, synthesis of ribosomes-in nucleolus, makes rRNA and subunits - 6What is the structure and function of cytoplasm?Fluid portion that surrounds organelles
Mostly water, remainder is molecules and nutrients required by cell - 7What is the structure and function of the golgi body?Small flattened membranous sacs
Proteins synthesised on RER pass through the golgi body - 8What is the structure and function of lysosomes?Membrane encolsed vesicles formed from golgi body
Break down molecules, digestion, recycle worn out cell parts - 9What is the structure and function of mitochondria?Site of ATP production
Double membraned organelle - 10What is the structure and function of the endoplasmic reticulum?RER: studded with ribosomes, synthesizes proteins for processing and sorting
SER: no ribosomes, contains enzymes that synthesize fatty acids and steroids - 11How does the nucleus help maintain homeostasis?Holds genetic material which directs all cellular activities and regulates cellular structure.
- 12What is the structure and function of the nucleolus?Round body inside nucleus
Makes ribosomal subunits from proteins and RNA called rRNA - 13What is transcription?The process of making an RNA copy of a gene sequence - mRNA
mRNA leaves the cell nucleus and enters the cytoplasm where it directs protein synthesis. - 14What is translation?The mRNA is translated to a sequence of amino acids during protein synthesis.
- 15What is the structure and function of cilia?Short, hairlike projections extending from surface of cell
Move fluid along cell surface - 16What is the structure and function of flagella?Longer hairlike projections extending from surface of cell
Move entire cell - 17What is the structure and function of microvilli?Microscopic cellular protrusions that increase surface area of cells.
- 18What is cell polarity?Differences in shape, structure and function of cells.
- 19What are the four types of tissues in the human body and what is their function?Epithelial tissue: covers surfaces, lines cavities, forms glands
Connective tissue: supports and protects other tissues
Muscle tissue: causes movement
Nervous tissue: receives and generates nerve impulses - 20What is the difference between simple and stratified cells?Simple: single cell- facilitates transfer between different environments. Easier to get across
Stratified: many cells-protective barrier function - 21What is the location, structure and function of simple squamous epithelium?Most delicate type of epithelium
Found in protected regions where absorption or diffusion occurs, where a slick, slippery surface reduces friction. e.g. internally
More efficient therefore absorption and diffusion
EXAMPLE: endothelium lining heart and blood vessels - 22What is the location, structure and function of stratified squamous epithelium?Where mechanical and chemical stress is severe.
e.g. lines regions of gut.
In exposed body surfaces where mechanical and dehydration are key issues - keratinised tissue
e.g. skin - 23What is the location, structure and function of cuboidal epithelium?Simple: lines exocrine glands and ducts. Found in kidneys.
Squamous: very rare because don't want to secrete across multiple layers. Sweat and mammary glands. - 24What is the location, structure and function of transitional epithelium?Unusual stratified epithelium. Found where repeated cycles of stretching and recoiling occur. e.g. bladder
- 25What is the location, structure and function of columnar epithelium?Simple: Found lining stomach, intestine, gall-bladder and uterine tubes. May have microvilli or cilia to increase SA = more diffusion and absorption
Stratified: rare due to diffusion and absorption. Found in large ducts e.g. salivary gland - 26What is the location, structure and function of glandular epithelium?Specialized for secretion.
Collections of epithelial cells that produce secretions are called glands.
Exocrine: release secretions into ducts opening onto epithelial surface
Endocrine: release secretions into interstitial fluid - 27What is the structure and function of cells of connective tissue?To synthesis, store and defend.
Structural cells: synthesis and store
Immature cells: blasts. synthesis and secrete ECM and divide & differentiate into mature cells
Mature cells: cytes. caretaker cells
Adipocytes: fat cells and store lipid
Defence cells: protect body against invasion. e.g. macrophages, mast cells, white blood cells - 28What is the structure and function of fibres of connective tissue?Collagen: provide strength
Reticular: provide net-like framework
Elastic: provide strength and elasticity - 29What is the structure and function of m matrix of connective tissue?Amorphous Ground Substance
Found between cells and fibres
Fluid (blood), semi fluid (cartilage), gelatinous (most others), hard (bone), secure CT cells & fibres within ECM
Provide medium for substance exchange - 30What are the properties of connective tissue?More extracellular matrix than cells.
CT= cells and matrix (ECM)
ECM= ground substance and fibres
CT function is determined by properties of ECM - 31What are the classifications of connective tissue?Loose connective tissue have more cells than fibres
Areolar connective tissue
Reticular connective tissue
Adipose connective tissue
Dense connective tissue have more fibres than cells
Dense regular connective tissue has fibres which run in parallel
Dense irregular connective tissue has fibres which run in all directions - 32What are the three types of muscle tissue?Cardiac, smooth and skeletal.
- 33Describe nervous tissue.Main component of the brain and spinal cord in nervous system. Composed of neurons which receive and transmit impulses and neuroglia which assist nerve impulses and provide nutrients to neuron.
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- University Biology (Year 1 Semester 1) FlashCards sobre Cells and Tissues, criado por Hannah Waters em 07-06-2016.
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- Hannah Waters
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