Biology Chapter 1.2: Cell Types

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Questions and Answers

What defines a polarized epithelial cell?

Both sides face the lumen

There are no distinct sides to the cell

One side faces the lumen and the other interacts with underlying structures (correct)

The cell is shaped like a cube

Which of the following best describes pseudostratified epithelium?

Made entirely of squamous cells

Contains multiple layers of cells

Only has one layer that appears multi-layered due to varying cell heights (correct)

Is limited to the gastrointestinal tract

What is the main function of connective tissue?

Absorb nutrients from the lumen

Provide a framework and support for epithelial cells (correct)

Act as a barrier against pathogens

Facilitate the secretion of hormones

Which of the following cell shapes is characteristic of cuboidal epithelium?

Cube-shaped Signup and view all the answers

Which type of connective tissue is responsible for forming the extracellular matrix?

Most cells in connective tissues producing collagen and elastin Signup and view all the answers

What is the primary role of peroxisomes in a cell?

Breakdown of very long chain fatty acids Signup and view all the answers

Which structure is involved in the transport of materials throughout the cell?

Cytoskeleton Signup and view all the answers

What type of filament is primarily responsible for muscle contraction?

Microfilaments Signup and view all the answers

What is the structure called that makes up cilia and flagella?

9 + 2 structure Signup and view all the answers

Which organelle is primarily involved in the synthesis of phospholipids?

Peroxisomes Signup and view all the answers

What type of tissue provides protection and covers body surfaces?

Epithelial tissue Signup and view all the answers

What protein structure serves as the organizing center for microtubules?

Centrioles Signup and view all the answers

What is the role of kinesin and dynein in the cell?

Transport of vesicles Signup and view all the answers

Which cytoskeletal component is known for its resistance to tension?

Intermediate filaments Signup and view all the answers

What type of cells have high concentrations of mitochondria due to their energy needs?

Sperm cells Signup and view all the answers

Which component of the cytoskeleton is made of polymerized rods of actin?

Microfilaments Signup and view all the answers

How do epithelial cells typically maintain cohesion?

Tight junctions Signup and view all the answers

What is one of the main features characterizing the cytoskeleton?

Provides structural support Signup and view all the answers

Which type of tissue supports and integrates various structures in the body?

Connective tissue Signup and view all the answers

What is the primary distinction between prokaryotic and eukaryotic organisms?

Eukaryotic cells have a true nucleus. Signup and view all the answers

Which of the following structures is not found in prokaryotic cells?

Nucleus Signup and view all the answers

What process do eukaryotic cells use for reproduction?

Mitosis Signup and view all the answers

What is the primary function of the nuclear membrane?

To regulate transport between the nucleus and cytoplasm Signup and view all the answers

What composition primarily makes up the cell membrane in eukaryotic cells?

Phospholipid bilayer Signup and view all the answers

Which of the following components is essential for the diffusion of molecules within a eukaryotic cell?

Cytosol Signup and view all the answers

Why is the nucleus considered the control center of the cell?

It contains the genetic material required for replication. Signup and view all the answers

What characteristic of the eukaryotic cell membrane allows it to serve as a selective barrier?

Hydrophilic exterior and hydrophobic interior Signup and view all the answers

What is the primary function of nuclear pores in the nuclear membrane?

Permit selective two-way exchange of material Signup and view all the answers

Which process occurs in the nucleolus?

Synthesis of ribosomal RNA (rRNA) Signup and view all the answers

How does the structure of mitochondria support its function?

Cristae increase the surface area for the electron transport chain. Signup and view all the answers

What is the main role of the rough endoplasmic reticulum (RER)?

Translation of proteins destined for secretion Signup and view all the answers

What is the significance of the Golgi apparatus in cellular processes?

It modifies and packages cellular products for secretion. Signup and view all the answers

Which organelle is responsible for the degradation of cellular waste?

Lysosomes Signup and view all the answers

How is the mitochondrial matrix involved in cellular respiration?

It contains enzymes for the citric acid cycle. Signup and view all the answers

What distinguishes smooth endoplasmic reticulum (SER) from rough endoplasmic reticulum (RER)?

SER is responsible for lipid synthesis and detoxification. Signup and view all the answers

What triggers apoptosis through mitochondria?

Release of enzymes from the electron transport chain Signup and view all the answers

What is the intermembrane space in mitochondria?

The space between the inner and outer membranes Signup and view all the answers

What is indicated by the presence of a darker spot in the nucleus?

Presence of ribosomal RNA synthesis Signup and view all the answers

What important relationship exists between lysosomes and endosomes?

Endosomes transport material to lysosomes for degradation. Signup and view all the answers

Which property of mitochondria supports the theory of semi-autonomy?

They contain their own genes and replicate independently. Signup and view all the answers

What is the primary role of the nuclear envelope?

Separate the nucleus from the cytoplasm Signup and view all the answers

What is the outcome if lysosomal enzymes are released into the cell?

They lead to autolysis and degradation of cellular components. Signup and view all the answers

Study Notes

Cell Types

Prokaryotic cells are always unicellular, while eukaryotic cells can be unicellular or multicellular.
Eukaryotic cells feature a true nucleus enclosed by a membrane, unlike prokaryotic cells, which lack a nucleus.

Eukaryotic Cells

Eukaryotic cells have various membrane-bound organelles within a semifluid cytosol.
Membranes consist of a phospholipid bilayer with hydrophilic surfaces and a hydrophobic inner portion, acting as a selective barrier.
Genetic material is encoded in DNA, organized into chromosomes within the nucleus.

Nucleus

The nucleus serves as the control center and contains all genetic material for cell replication.
Surrounded by a double membrane (nuclear envelope) with nuclear pores for selective material exchange.
Contains a nucleolus, responsible for synthesizing ribosomal RNA, occupying about 25% of nucleus volume.

Mitochondria

Mitochondria, known as cell power plants, have an outer membrane and an inner membrane with infoldings called cristae.
Cristae increase surface area for electron transport chain enzymes; the mitochondrial matrix houses metabolic functions.
Mitochondria are semi-autonomous, containing their own DNA and replicating independently via binary fission.
Involved in energy production and can induce apoptosis by releasing enzymes.

Lysosomes

Membrane-bound structures contain hydrolytic enzymes to break down substrates, cellular waste, and materials from endocytosis.
Function alongside endosomes for material transport; they can instigate autolysis when enzymes are released.

Endoplasmic Reticulum (ER)

Composed of interconnected membranes, ER includes rough ER (with ribosomes) for protein synthesis and smooth ER (lacking ribosomes) for lipid synthesis and detoxification.
Smooth ER also transports proteins to the Golgi apparatus.

Golgi Apparatus

Composed of stacked membrane-bound sacs modifying cellular products from the ER by adding various groups.
Responsible for packaging these products into vesicles for targeted delivery, including secretion via exocytosis.

Peroxisomes

Contain hydrogen peroxide and assist in the breakdown of very long-chain fatty acids through β-oxidation.
Play a role in phospholipid synthesis and participate in the pentose phosphate pathway.

Cytoskeleton

Provides structure and shape, facilitating material transport within the cell; composed of microfilaments, microtubules, and intermediate filaments.

Microfilaments

Made of actin, these resist compression and support cell movement, playing a key role in muscle contraction and cytokinesis during cell division.

Microtubules

Hollow polymers of tubulin that create pathways for motor proteins such as kinesin and dynein.
Form cilia and flagella, important for cell movement and material transport along the cell surface.

Intermediate Filaments

Diverse proteins providing structural rigidity, anchoring organelles, and aiding in cell-cell adhesion.

Tissue Formation

Eukaryotic cells can form specialized tissues with specific functions, comprised of four main types: epithelial, connective, muscle, and nervous tissue.

Epithelial Tissue

Covers body surfaces and lines cavities, providing protection and facilitating absorption/secretion.
Cells are tightly joined to each other and to a basement membrane; classified by layers (simple, stratified, pseudostratified) and shape (cuboidal, columnar, squamous).

Connective Tissue

Supports body structure and framework for epithelial cells; examples include bone, cartilage, and blood.
Connective tissues secrete materials like collagen and elastin, forming the extracellular matrix.

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Description

This quiz focuses on the differences between prokaryotic and eukaryotic cells, highlighting their structures, organelles, and cellular organization. Understand the key features that distinguish these two major categories of living organisms. Test your knowledge on cell biology fundamentals.