Biology Lesson 1.1: Cell Theory

Questions and Answers

Who was the first person to use the term 'cell' to describe the structures within cork?

Hans & Zacharias Jenssen

Robert Hooke (correct)

Matthias Jakob Schleiden

Anton van Leeuwenhoek

Which of the following statements is NOT one of the postulates of the Cell Theory?

The cell is the basic unit of life.

All living organisms are composed of one or more cells.

All cells perform the same functions in an organism. (correct)

Cells arise from pre-existing cells.

What significant contribution did Rudolf Virchow make to the understanding of cells?

He stated that living things come from other living things. (correct)

He discovered that plants are made of cells.

He produced the first compound microscope.

He was the first to observe living cells.

What is the primary role of the nucleus in a eukaryotic cell?

Storing hereditary material or DNA Signup and view all the answers

Which scientist is credited with observing living cells through a simple microscope?

Anton van Leeuwenhoek Signup and view all the answers

Which organelle is known as the 'powerhouse of the cell'?

Mitochondria Signup and view all the answers

What is the primary function of the Golgi apparatus?

Sort, modify, and package macromolecules Signup and view all the answers

Which of the following structures is only present in eukaryotic cells?

Nuclear membrane Signup and view all the answers

What type of endoplasmic reticulum produces lipids?

Smooth endoplasmic reticulum Signup and view all the answers

What is the role of lysosomes in a cell?

Digestive waste disposal Signup and view all the answers

What is the structure of the cell membrane often described as?

Semi-permeable phospholipid bilayer Signup and view all the answers

Which component of the cell serves as the site of protein synthesis?

Ribosomes Signup and view all the answers

What describes cytosol in a cell?

The fluid within the cell membrane Signup and view all the answers

Which organelle is specifically involved in the detoxification processes within eukaryotic cells?

Peroxisomes Signup and view all the answers

What is the primary function of vacuoles in plant cells?

Store cell sap and waste products Signup and view all the answers

In which type of cell are centrioles primarily found?

Animal cells Signup and view all the answers

Which component of the cytoskeleton is primarily responsible for cell movement and support of cell shape?

Microfilaments Signup and view all the answers

What do plasmids represent in prokaryotic cells?

Extrachromosomal DNA Signup and view all the answers

Which structure protects prokaryotic cells from desiccation and assists with adherence?

Capsule Signup and view all the answers

What key role do microtubules play during mitosis in animal cells?

Organizing chromosomal alignment Signup and view all the answers

Which of the following organelles is involved in photosynthesis?

Chloroplasts Signup and view all the answers

Which type of filament provides mechanical support and stability to eukaryotic cells?

Intermediate filaments Signup and view all the answers

What role do pili play in prokaryotic cells?

Attachment to surfaces Signup and view all the answers

What function do intercalary meristems primarily serve in plants?

Contribute to the elongation of internodes Signup and view all the answers

Which types of meristematic tissues are crucial for secondary growth in plants?

Vascular cambium and cork cambium Signup and view all the answers

Which of the following describes permanent tissues in plants?

Tissues that have differentiated and cannot divide Signup and view all the answers

Which type of simple permanent tissue is primarily involved in storing organic products in plants?

Parenchyma Signup and view all the answers

Where can parenchyma cells commonly be found in plants?

In dermal, ground, and vascular tissues Signup and view all the answers

What is a distinguishing characteristic of collenchyma tissue?

Has thickened cell walls for support Signup and view all the answers

Which of the following statements about lateral meristems is correct?

They divide radially and increase the thickness of stems and roots. Signup and view all the answers

In which types of plant tissues would you typically find parenchyma cells?

Ground tissue as part of mesophyll Signup and view all the answers

What is the primary function of the shoot system in vascular plants?

Photosynthesis through leaves Signup and view all the answers

What quality of meristematic tissue allows it to continuously produce specialized structures?

Self-renewal capacity Signup and view all the answers

Which type of meristematic tissue is located at the tips of roots and shoots?

Apical Meristems Signup and view all the answers

Which characteristic is NOT associated with meristematic tissue?

Presence of intercellular spaces Signup and view all the answers

What is the role of the root system in vascular plants?

Supporting the plant structure Signup and view all the answers

Which of the following is a characteristic of meristematic cells?

Undifferentiated and actively dividing Signup and view all the answers

What primarily occurs in the meristematic tissue during cellular division?

One cell remains identical while others specialize Signup and view all the answers

What is a key function of meristematic tissue in plants?

Healing wounds of injured plants Signup and view all the answers

Study Notes

Cell Theory

Robert Hooke first described cells in cork and plant tissue in 1665, coining the term "cell" from "cellula" due to their resemblance to monk cells.
Hans & Zacharias Jenssen invented the first compound microscope in 1590.
Anton van Leeuwenhoek observed living cells in the 1680s through a simple microscope.
Matthias Jakob Schleiden concluded in 1838 that plants are composed of cells.
Rudolf Virchow proposed in 1855 that all living cells come from pre-existing cells, summarizing with "Omnis cellula e cellulae."
The three postulates of cell theory:
- All living organisms consist of one or more cells.
- The cell is the fundamental unit of life.
- Cells originate from pre-existing cells.

Prokaryotic and Eukaryotic Cell Structures

Eukaryotic Cell Organelles

Nucleus: The cell's control center, storing DNA and regulating activities; exclusive to eukaryotic cells.
Nuclear Membrane: Protects the nucleus and regulates material movement; exclusive to eukaryotic cells.
Endoplasmic Reticulum (ER): Synthesizes proteins (rough ER) and lipids (smooth ER); exclusive to eukaryotic cells.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids; known as the "post office" of the cell; exclusive to eukaryotic cells.
Ribosomes: Sites of protein synthesis, found in both eukaryotic and prokaryotic cells.
Mitochondria: Powerhouse of the cell, converting energy from food into ATP; exclusive to eukaryotic cells.
Cell Membrane: Semi-permeable layer controlling movement in and out of cells; present in both cell types.
Cytosol: The fluid within the cell membrane, present in both cell types.
Cytoplasm: Fluid that suspends cell parts; present in both cell types.
Lysosome: Contains enzymes to break down waste; primarily found in animal cells.
Peroxisomes: Detoxification centers converting fatty acids into hydrogen peroxide, then to water; exclusive to eukaryotic cells.
Vacuoles: Storage sacs larger in plant cells, storing various substances; found in plant cells.
Cytoskeleton: Provides structural support and facilitates movement; found in eukaryotic cells.
Centrioles: Organizing centers for microtubules during cell division; found only in animal cells.
Chloroplasts: Site of photosynthesis, containing chlorophyll; exclusive to plant cells.

Prokaryotic Cell Organelles

Capsule: Protective layer aiding in adherence and preventing desiccation; exclusive to prokaryotic cells.
Cell Wall: Composed of murein, providing support and protection; found in prokaryotic and plant cells.
Pili: Short appendages for attachment and genetic material exchange; exclusive to prokaryotic cells.
Nucleoid Region: Contains genetic material unprotected by a membrane; exclusive to prokaryotic cells.
Flagella: Organelle providing locomotion; exclusive to prokaryotic cells.
Plasmids: Extra DNA molecules that can enhance survival; found in prokaryotic cells.
Inclusion Bodies: Storage compartments for nutrients; found in prokaryotic cells.
Fimbriae: Shorter structures aiding in adherence; exclusive to prokaryotic cells.

Plant Tissues

Plants are multicellular eukaryotes with specialized tissues and organs.
Vascular plants, other than mosses and liverworts, consist of distinct growing tissues categorized into a shoot system (stems, leaves) and a root system (water and mineral absorption).

Meristematic Tissue

Defined by undifferentiated living cells necessary for plant growth and development.
Meristematic cells have dense protoplasm, large nuclei, and actively divide to form specialized structures.
Types include:
- Apical Meristems: Located at tips of roots/shoots, responsible for height growth.
- Intercalary Meristems: Found in leaves and internodes, aiding elongation.
- Lateral Meristems: Found on the sides of stems/roots, increasing thickness.

Permanent Tissue

Composed of matured cells that can no longer divide; formed from meristematic tissue.
Simple Permanent Tissue: Homogeneous, made of one cell type; includes:
- Parenchyma: Supportive, found in various plant parts, including mesophyll, involved in nutrient storage and exchange.

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Description

Test your knowledge on the fundamentals of Cell Theory with this quiz. Learn about Robert Hooke's contributions and the timeline of key proponents in the development of this essential concept in biology. Perfect for 1st-quarter reviewers in biology classes!