Cell Structure: Chromatin and Organelles

Questions and Answers

What is the primary function of mitochondria in eukaryotic cells?

Break down fatty acids

Site of aerobic respiration and ATP synthesis (correct)

Contains rigid cell membranes

Forms a double layer of molecules

What characteristic is unique to prokaryotic cells?

Single-celled organisms like bacteria (correct)

Larger and more complex structure

Contain various organelles including mitochondria

Presence of membrane-bound nucleus

Which characteristic distinguishes eukaryotic cells from prokaryotic cells?

Lack of organelles

Smaller size

Presence of membrane-bound nucleus (correct)

Rigid cell membrane

What do phospholipids form in a cell membrane?

Double layer with polar hydrophilic ends Signup and view all the answers

What does isotonic solution refer to in relation to cell environments?

Equal concentration of water and solute inside and outside the cell Signup and view all the answers

What is the primary function of lysosomes within the cell?

Digesting material taken into the cell Signup and view all the answers

What role do centrioles play in a cell?

Facilitate movement of chromosomes during cell division Signup and view all the answers

Which of the following structures is involved in detoxification?

Golgi apparatus Signup and view all the answers

Which structure primarily helps in moving substances over the surfaces of certain cells?

Cilia Signup and view all the answers

What is the function of microfilaments in muscle cells?

Enable contraction of the cells Signup and view all the answers

What do microvilli primarily do?

Increase surface area of certain cells Signup and view all the answers

What are chromosomes primarily made of?

DNA Signup and view all the answers

Which molecules primarily make up the cell membrane?

Phospholipids and proteins Signup and view all the answers

What process involves the active transport of one substance across the cell membrane to establish a concentration gradient?

Secondary active transport Signup and view all the answers

Which of the following describes the process of phagocytosis?

Cell-eating mechanism used for solid particle absorption Signup and view all the answers

What is the primary result of a cell being placed in a hypotonic solution?

The cell becomes inflamed or swelled Signup and view all the answers

During which phase of cell division do the chromatin condense into visible chromosomes?

Prophase Signup and view all the answers

What term describes the process of liquid particles being absorbed by a cell?

Pinocytosis Signup and view all the answers

What is the structure that contains the genetic material of the cell?

Nucleus Signup and view all the answers

What are ribosomes primarily responsible for?

Synthesis of protein Signup and view all the answers

What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?

Presence of ribosomes Signup and view all the answers

Which of the following statements about the cell membrane is correct?

It encloses the cytoplasm of the cell. Signup and view all the answers

What type of substances are referred to as extracellular?

Substances outside the cell Signup and view all the answers

What is the main component of the cytoplasm?

Cytosol Signup and view all the answers

Which organelle is known for synthesizing nucleic acids?

Nucleus Signup and view all the answers

What is the purpose of the nuclear pores?

Transport of materials in and out of the nucleus Signup and view all the answers

What is the process of programmed cell death called?

Apoptosis Signup and view all the answers

Which phase of the cell cycle involves DNA synthesis?

S phase Signup and view all the answers

What occurs during anaphase?

Chromatids are separated Signup and view all the answers

Which of the following describes transcytosis?

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

What is the function of the centromere?

Connects chromatids Signup and view all the answers

What defines differentiation in the context of cellular biology?

Development of a specialized function from stem cells Signup and view all the answers

Which cellular process involves the release of substances through the fusion of a vesicle with the cell membrane?

Exocytosis Signup and view all the answers

What structure is DNA known for having?

Double helix structure Signup and view all the answers

Study Notes

Cell Structure and Components

Chromatin: Loosely coiled chromosomes within the nucleus.
Organelles: Tiny structures performing specific functions within cells.
Cytoplasm: Jelly-like fluid surrounding the nucleus, containing organelles and cytoplasmic inclusions.
Cell Membrane: Encloses the cytoplasm, forming a barrier between the internal and external environments.

Key Cellular Functions

Cell Metabolism: Involves chemical reactions that occur within cells.
Synthesis: Cells produce proteins, nucleic acids, and lipids.
Communication: Cells send and receive signals for interaction.
Reproduction & Inheritance: Cells contain genetic information for reproduction.

Organelle Functions and Locations

Nucleus: Contains DNA and nucleoli; site for RNA synthesis and ribosomal assembly.
Ribosomes: Located in the cytoplasm; sites for protein synthesis.
Rough Endoplasmic Reticulum (RER): Has ribosomes; involved in protein synthesis.
Smooth Endoplasmic Reticulum (SER): Lacks ribosomes; synthesizes lipids and detoxifies substances.
Golgi Apparatus: Modifies and packages proteins into secretory vesicles.
Centrioles: Facilitate chromosome movement during cell division.
Lysosomes: Contain digestive enzymes; breakdown of materials in the cell.
Cilia: Move substances over surfaces of certain cells.
Flagella: Propel sperm cells; consist of hydrophilic head and hydrophobic tail.
Microvilli: Extensions that increase cell surface area.
Mitochondria: Site of aerobic respiration and ATP synthesis; known as the powerhouse of the cell.
Peroxisomes: Break down fatty acids and hydrogen peroxide.

Cell Types

Prokaryotes: Single-celled organisms (e.g., bacteria); lack a membrane-bound nucleus.
Eukaryotes: Multicellular organisms (e.g., humans, plants); possess a membrane-bound nucleus.

Solutions and Transport Mechanisms

Isotonic Solution: Equal concentrations of water and solute inside and outside the cell.
Hypertonic Solution: Higher concentration of solute outside the cell, causing cell shrinkage.
Hypotonic Solution: Higher concentration of water outside the cell, causing swelling.
Membrane Transport:
- Active Transport: Movement against concentration gradient using energy.
- Endocytosis: Involves vesicles bringing materials into the cell.
  - Phagocytosis: "Cell eating" for solid particles.
  - Pinocytosis: "Cell drinking" for liquid particles.
- Exocytosis: Release of substances from the cell via vesicles.
- Transcytosis: Involves transporting substances through the cell via vesicles.

Cell Cycle and Mitosis

Mitosis: Cell division leading to two daughter cells.
- Chromatid: Two identical strands of chromatin.
- Centromere: Area where chromatids are attached.
Phases of Cell Cycle:
- G1 Phase: Routine metabolism.
- S Phase: DNA synthesis.
- G2 Phase: Preparation for division.

Genetic Material

DNA (Deoxyribonucleic Acid): Double helix structure containing genetic information.
- Components: Deoxyribose sugar, nitrogenous base, phosphate group.
Genetic Code: mRNA contains codons that translate into amino acids for protein synthesis.
Apoptosis: Programmed cell death, regulates tissue cells.
Differentiation: Process where stem cells develop specialized functions.

Additional Notes

Cell membrane composition includes phospholipids, proteins, cholesterol, and carbohydrates.
Microfilaments and microtubules provide structural support and facilitate cell movement.
Secretory vesicles transport materials produced in cells for exocytosis.

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Description

This quiz explores the structure of cells, focusing on chromatin and various organelles. Understand the functions of the nucleus, cytoplasm, and other important components that contribute to cellular activity. Test your knowledge on the intricacies of cell biology!