Cell Biology: Cellular Structures & Tissues

Questions and Answers

Which type of epithelial tissue is responsible for the selective transport of substances?

Columnar Epithelium

Cuboidal Epithelium

Squamous Epithelium (correct)

Ciliated Epithelium

What is the primary function of the centrosome in animal cells?

Organizing the spindle apparatus during cell division (correct)

Producing energy for the cell

Synthesizing proteins

Creating cytoplasm

What structural arrangement is found within cilia and flagella?

A single row of microtubules

Triplet microtubules only

A 9+2 arrangement of microtubules (correct)

A double-layer of lipid membrane

Centrioles are associated with which cellular process?

Spindle formation during cell division Signup and view all the answers

Which type of animal tissue is responsible for connecting and supporting body parts?

Connective and Supportive Tissues Signup and view all the answers

What role do centrioles play in higher plant cells?

They are mostly absent Signup and view all the answers

Which epithelial tissue type is primarily involved in reabsorption of useful substances from urine?

Cuboidal Epithelium Signup and view all the answers

What is the main composition of the microtubules found in cilia and flagella?

Tubulin dimers Signup and view all the answers

What is the primary function of food vacuoles in amoeba?

Digestion of nutrients Signup and view all the answers

What distinguishes bound ribosomes from free ribosomes?

Bound ribosomes are attached to the rough endoplasmic reticulum. Signup and view all the answers

Which of the following statements is true about plant vacuoles?

They contain enzymes that degrade and recycle molecules. Signup and view all the answers

What is the primary role of mitochondria in a cell?

Production of ATP through cellular respiration Signup and view all the answers

What is the function of the cytoskeleton in a eukaryotic cell?

Providing structural support and transportation Signup and view all the answers

Which of the following is NOT a function of microfilaments?

Facilitate movement of organelles within the cell Signup and view all the answers

What is the diameter of intermediate filaments compared to other cytoskeletal components?

Thicker than microfilaments but thinner than microtubules Signup and view all the answers

Which component is responsible for synthesizing proteins within the cell?

Ribosome Signup and view all the answers

Which statement about mitochondrial DNA is true?

It encodes proteins essential for mitochondrial structure. Signup and view all the answers

What is the primary role of cristae within mitochondria?

To catalyze cellular respiration Signup and view all the answers

What distinguishes the domain Archaea from Bacteria?

Archaea are more closely related to eukaryotes than to bacteria. Signup and view all the answers

Which of the following describes a characteristic of life?

Living things grow and develop. Signup and view all the answers

Who coined the term 'cell' in relation to living organisms?

Robert Hooke Signup and view all the answers

Which of the following is true about eukaryotic cells compared to prokaryotic cells?

Eukaryotic cells are generally more complex than prokaryotic cells. Signup and view all the answers

What is the role of energy in living organisms?

Energy is needed to fuel various life processes. Signup and view all the answers

What does maintaining internal balance refer to in living organisms?

Remaining stable despite changes in the external environment. Signup and view all the answers

Which statement best describes the findings of Matthias Schleiden?

All plants have cells. Signup and view all the answers

Which characteristic is related to the evolutionary aspect of life?

Living things undergo changes over time for adaptation. Signup and view all the answers

What is the primary function of the rough endoplasmic reticulum?

Synthesize housekeeping and secretory proteins Signup and view all the answers

What do lysosomes primarily contain that allows them to break down various cellular content?

Hydrolytic enzymes Signup and view all the answers

What is the role of the Golgi apparatus in a eukaryotic cell?

Complete protein folding and modification Signup and view all the answers

Which statement correctly describes the smooth endoplasmic reticulum?

It is responsible for synthesizing lipids. Signup and view all the answers

What is the primary function of the cell membrane?

Transport substances into and out of the cell Signup and view all the answers

What do peroxisomes in a eukaryotic cell primarily do?

Break down fatty acids and produce cholesterol Signup and view all the answers

Which component of the cell is primarily responsible for controlling cellular functions?

Nucleus Signup and view all the answers

What are vacuoles responsible for in protists such as paramecia?

Pumping out excess water Signup and view all the answers

What role does the cytoplasm play in a eukaryotic cell?

Contains organelles and facilitates metabolic reactions Signup and view all the answers

Which structure is known as the 'post office' of the cell?

Golgi Apparatus Signup and view all the answers

Study Notes

Cellular Structures and Functions

Microtubules: Composed of tubulin dimers; form "trackways" for substance movement within cells; involved in chromosome separation during cell division.
Centrosome: Spherical structure in animal cells only; organizes spindle apparatus for chromosome movement; contains two centrioles.
Centrioles: Cylindrical structures oriented at right angles; assist in spindle formation; lack in most higher plant cells; indirectly produce cilia and flagella.
Cilium and Flagellum: Structures for locomotion; have a 9+2 arrangement of microtubules.

Types of Tissues

Animal Tissues: Four main types include connective, epithelial, muscular, and nervous.
- Connective Tissue: Supports and connects body parts.
- Epithelial Tissue: Protects body surfaces; three types are:
  - Squamous Epithelium: Facilitates selective transport; found in lungs and blood vessels.
  - Cuboidal Epithelium: Involved in substance reabsorption; found in kidney tubules.
  - Columnar Epithelium: Secretes digestive juices; found in digestive tract lining.
- Muscular Tissue: Enables body movement.
- Nervous Tissue: Controls and coordinates body functions.

Domain Classification

Three Domains of Life: Bacteria, Archaea, Eukarya.
- Bacteria: Prokaryotic cells known as eubacteria; true bacteria.
- Archaea: Ancient bacteria, believed to be first living organisms, more related to eukaryotes than bacteria.
- Eukarya: Organisms with eukaryotic cells.

Characteristics of Life

Organization: Living things consist of parts arranged in hierarchical structure.
Energy Requirement: Living organisms acquire and utilize energy and nutrients for various life processes.
Internal Balance: Maintaining stable internal conditions despite external changes.

Cell Theory

Composed of three main postulates:
- All living things are made of one or more cells.
- The cell is the basic unit of life.
- All new cells arise from pre-existing cells, a concept supported by Louis Pasteur.

Eukaryotic Cell Components

Cell Membrane: Separates cytoplasm from the environment; regulates substance transport; acts as the cell's gatekeeper.
Cytoplasm: Site for metabolic reactions; houses organelles and cytoskeletal filaments.
Nucleus: Controls cell functions; contains nuclear membrane, nucleoplasm, chromosomes, and nucleolus.
Endoplasmic Reticulum (ER):
- Rough ER: Studded with ribosomes; synthesizes proteins.
- Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies drugs.
Golgi Apparatus: Stack of sacs modifying and packaging proteins; serves as the cell's "post office."
Lysosome: Contains hydrolytic enzymes for recycling cellular components; involved in apoptosis.
Peroxisome: Contains enzymes for detoxification and fatty acid breakdown.

Mitochondrion

Function: Site of cellular respiration; power generator of the cell producing ATP through metabolic processes.
Structure: Consists of cristae, matrix, and mitochondrial DNA.

Ribosome

Role: Site for protein synthesis; decodes mRNA to produce proteins; consists of two subunits (large and small).

Cytoskeleton

Structure: Intricate network of protein filaments and tubules; provides structural support and facilitates transportation within the cell.
Components:
- Microfilaments: Thinnest filaments providing strength and anchoring cells.
- Intermediate Filaments: Maintain cell shape and resist mechanical stress.
- Microtubules: Hollow tubes that support cell structure and aid in intracellular transport.

Vacuoles

Function in Protists:
- Contractile Vacuoles: In paramecia, expel excess water;
- Food Vacuoles: In amoeba, digest nutrients engulfed through phagocytosis.
Animal Vacuoles: Store water and food, excreting waste through exocytosis.
Plant Vacuoles: Aqueous solutions containing enzymes that degrade and recycle cellular components.

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Description

Explore the intricate world of cellular structures and the various types of tissues in animals. This quiz covers the role of microtubules, centrioles, and the classification of animal tissues, including connective and epithelial types. Test your knowledge on how these structures function within living organisms.