Unveiling Eukaryotic Cell Secrets

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What is a characteristic of eukaryotic cells?

Their genetic material is not enclosed by a nuclear membrane

They have a true nucleus enclosed by a nuclear membrane (correct)

They have genetic material spread throughout the cytoplasm

They lack a true nucleus

What is a typical feature of eukaryotic cells?

Contain membrane-bound organelles (correct)

Lack membrane-bound organelles

Have a cell wall composed of peptidoglycan

Lack a plasma membrane

What distinguishes eukaryotic cells from prokaryotic cells?

Absence of a true nucleus enclosed by a nuclear membrane

Lack of a plasma membrane

Presence of membrane-bound organelles (correct)

Absence of genetic material

Which organelle is absent in prokaryotic cells?

Mitochondria Signup and view all the answers

What is a membrane-bound organelle present in eukaryotic cells but absent in prokaryotic cells?

Golgi apparatus Signup and view all the answers

Which organelle is specific to plant cells and not found in prokaryotic cells?

Chloroplasts Signup and view all the answers

What is the genetic characteristic of prokaryotic cells?

Haploid with a single chromosome Signup and view all the answers

What is the role of histones in eukaryotic cells that is not present in prokaryotic cells?

Help package DNA Signup and view all the answers

What is the composition of 70S ribosomes found in bacteria?

30S and 50S subunits Signup and view all the answers

Which type of prokaryotes is mentioned as an exception with more complex lipid molecules in their membranes?

Mycoplasma species Signup and view all the answers

Which of the following lipid molecules are NOT mentioned as present in the membranes of prokaryotes with complex lipids?

Waxes Signup and view all the answers

Which of the following genera form endospores in harsh conditions?

Bacillus and Clostridium Signup and view all the answers

In what conditions do certain genera form endospores?

Harsh conditions Signup and view all the answers

What are endospores?

Dormant, asexual spores within active bacterial cells Signup and view all the answers

In what type of cells are endospores found?

Bacterial cells (active vegatative cells) Signup and view all the answers

How are endospores visualized microscopically with Gram stain?

As unstained areas Signup and view all the answers

Which stain can be used to specifically visualize endospores? (multiple answers)

Schaeffer-Fulton stain Signup and view all the answers

What is the main component of the plasma membrane in prokaryotes?

Phospholipids bilayer and proteins Signup and view all the answers

Which type of cells do not contain sterols in their plasma membranes?

Prokaryotic cells Signup and view all the answers

What distinguishes the plasma membrane of eukaryotic cells from that of prokaryotic cells?

Presence of sterols Signup and view all the answers

Which type of prokaryotes is an exception in terms of plasma membrane composition?

Mycoplasma spp. Signup and view all the answers

What is the primary function of the plasma membrane in prokaryotes?

Acting as an osmotic barrier and location of the electron transport chain Signup and view all the answers

Which process occurs at the location of the plasma membrane in prokaryotes?

Electron transport chain for energy production Signup and view all the answers

Apart from serving as an osmotic barrier, what other function does the plasma membrane have in prokaryotes?

Location of the electron transport chain Signup and view all the answers

What is the primary function of the cell wall?

Maintains the shape of the cell Signup and view all the answers

How are types of cell walls categorized?

Based on their staining characteristics: Gram-positive and Gram-negative Signup and view all the answers

What is the primary component of the gram-positive cell wall?

Peptidoglycan Signup and view all the answers

What are the glycan chains in the peptidoglycan layer of the gram-positive cell wall composed of?

alternating N-acetylglucosamine and N-acetylmuramic acid Signup and view all the answers

What is the unique feature of the Gram-positive cell wall?

Teichoic acid and lipoteichoic acid Signup and view all the answers

Where is lipoteichoic acid anchored in the Gram-positive cell wall?

To the plasma membrane Signup and view all the answers

Where is teichoic acid anchored in the Gram-positive cell wall?

To the murein Signup and view all the answers

What is the primary function of teichoic acid in the Gram-positive cell wall?

Providing structural support Signup and view all the answers

Which component is teichoic acid anchored to in the Gram-positive cell wall? two answers

Murein Signup and view all the answers

What is the composition of the outer membrane unique to the Gram-negative cell wall?

Lipopolysaccharides, proteins, phospholipids Signup and view all the answers

What distinguishes the inner peptidoglycan layer of Gram-negative cell walls from that of Gram-positive cell walls?

It is much thinner Signup and view all the answers

What is responsible for producing fever and shock conditions in patients infected with Gram-negative bacteria?

Inner lipid A (endotoxin) Signup and view all the answers

Where is the periplasmic space located in Gram-negative bacteria?

Between the inner and outer membrane Signup and view all the answers

What are the three regions of LPS?

Antigenic O-specific polysaccharide, core polysaccharide, inner lipid A Signup and view all the answers

What is the primary stain used to visualize Mycobacterium and Nocardia?

Ziehl-Neelsen Signup and view all the answers

What is the waxy cell wall of Mycobacterium and Nocardia primarily composed of? (mulitple)

layer of glycolipids Signup and view all the answers

Which of the following genera have a Gram-positive cell wall structure and a waxy layer of glycolipids and fatty acids?

Mycobacterium Signup and view all the answers

Which of the following bacteria lack a cell wall?

Mycoplasma spp. and Ureaplasma spp. Signup and view all the answers

What is a distinguishing feature of Mycoplasma spp. and Ureaplasma spp. cell membranes?

Contain sterols Signup and view all the answers

Which of the following is a characteristic of Mycoplasma spp. and Ureaplasma

Ability to assume variable shapes Signup and view all the answers

What are capsules primarily made of?

Polysaccharide polymers or polypeptides Signup and view all the answers

What is the role of capsules in pathogenicity? multiple answers

Helping the pathogen evade phagocytosis Signup and view all the answers

How does a slime layer differ from a capsule?

It is a more diffuse layer surrounding the cell Signup and view all the answers

What are flagella in bacteria primarily responsible for?

Causing motility Signup and view all the answers

What is the primary function of pili/fimbriae in bacterial cells?

Adhering cells to surfaces and mediating DNA exchange Signup and view all the answers

What is the primary difference between flagella and pili/fimbriae in bacterial cells?

Flagella cause bacteria to be motile, while pili/fimbriae adhere cells to surfaces and mediate DNA exchange Signup and view all the answers

Which bacterial shape is characterized by a spiral structure?

Spirochetes Signup and view all the answers

What term is used to describe a species varying in size and shape within a pure culture?

Pleomorphic Signup and view all the answers

Which bacterial shape is characterized by a rod-like structure?

Bacilli Signup and view all the answers

Which bacterial shape is characterized by a spherical structure?

Cocci Signup and view all the answers

Which bacteria are associated with cocci shape?

Staphylococcus spp. Signup and view all the answers

Which bacteria are associated with bacilli shape?

Escherichia coli Signup and view all the answers

Which bacteria are associated with spirochetes shape?

Treponema pallidum Signup and view all the answers

What is a common structure in which bacterial cells are arranged?

chains, pairs, cubical bundles, flat plates Signup and view all the answers

Which bacteria are associated with grape-like clusters?

Staphylococcus spp Signup and view all the answers

Which bacteria are found in pairs? multiple

Streptococcus pyogenes Signup and view all the answers

Which bacteria are found in chains?

Streptococcus spp Signup and view all the answers

What represents 50% of the dry weight of a bacterium?

Carbon Signup and view all the answers

What makes up 14% of the dry weight of a bacterium?

Nitrogen Signup and view all the answers

What is needed for performing cellular functions in bacteria?

Adenosine triphosphate (ATP) Signup and view all the answers

What is the primary nutritional need for making cellular constituents in bacteria?

Source of carbon Signup and view all the answers

What are the three major nutritional needs for growth in bacteria

source of carbon, nitrogen, and energy Signup and view all the answers

What is the primary difference between autotrophs and heterotrophs?

Autotrophs use carbon dioxide as the sole source of carbon, while heterotrophs require an organic source of carbon Signup and view all the answers

How do autotrophs obtain energy?

Photosynthetically Signup and view all the answers

What is a defining characteristic of all bacteria that inhabit the human body?

They are heterotrophs Signup and view all the answers