Questions and Answers
Who is credited with coining the term 'cell'?
What type of cell division do prokaryotic cells primarily undergo?
What distinguishes eukaryotic cells from prokaryotic cells?
Which cellular process involves breaking down complex molecules to produce energy?
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What is the primary function of the cell membrane?
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Which organelle is primarily responsible for protein synthesis?
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What does the nucleus of a cell contain?
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What is the function of the rough endoplasmic reticulum?
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What is the primary function of ribosomes in a cell?
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What structure is responsible for modifying and packaging proteins in the cell?
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What is the main role of the smooth endoplasmic reticulum?
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Which organelle is known as the powerhouse of the cell?
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What is the role of centrioles in animal cells?
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Which component of the cell's internal environment holds all organelles in place?
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How does the nuclear envelope benefit the DNA inside the nucleus?
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What is the main function of lysosomes in a cell?
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What is the first step to prepare a microscope for observing a specimen?
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Which adjustment wheel is used to obtain a clearer image after focusing the specimen initially?
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What action should one take when wishing to explore the specimen on the microscope?
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In which order should the objective lenses be used while observing a specimen?
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Why is it necessary to use both the coarse and fine adjustment wheels?
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What is the function of a microscope?
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Which statement about cells is correct?
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What should be done after observing a specimen sufficiently?
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Study Notes
What are Cells?
- Cells are the smallest building blocks of living beings and the fundamental structure of organisms.
- Organisms can be unicellular (made of one cell) or multicellular (made of many cells).
- Humans have approximately 37.2 trillion cells.
Discovery of the Cell
- Robert Hooke coined the term "cell" in 1665 after observing cells under a microscope.
- He is credited with the invention of the compound microscope and identified the cell as the basic unit of life.
Types of Cells
- Eukaryotic Cells: Have a true nucleus and contain DNA, with cell division occurring by mitosis or meiosis.
- Prokaryotic Cells: Lack a true nucleus and have a nucleoid instead of DNA, with cell division occurring by binary fission.
Cell Growth and Metabolism
- Cell growth is achieved through metabolism, which is divided into:
- Catabolism: Breaks down complex molecules to produce energy.
- Anabolism: Utilizes energy to construct necessary molecules and perform biological functions.
Functions of Cells
- Key functions include cell division, transport, and metabolism.
- Cells transport substances through the cell membrane.
Cell Organelles
- Organelles are mini-organ systems within a cell, including:
- Cell membrane
- Nucleus
- Ribosomes
- Rough and smooth endoplasmic reticulum
- Golgi apparatus
- Centrioles
- Mitochondria
- Vacuoles
- Cytoplasm
Cell Membrane
- Comprised of a phospholipid bilayer, it is semi-permeable and controls substance entry.
- The phospholipid head is hydrophilic, while the tail is hydrophobic.
Nucleus
- Encloses DNA within a double membrane called the nuclear envelope, featuring pores for substance exchange.
- Chromatin condenses to form chromosomes during cell division, and ribosomes are produced in the nucleolus.
Ribosomes
- Responsible for protein synthesis as directed by DNA.
- Can be found free in the cytoplasm or attached to the rough endoplasmic reticulum.
Endoplasmic Reticulum
- Rough Endoplasmic Reticulum: Studded with ribosomes that synthesize proteins for internal use or export.
- Smooth Endoplasmic Reticulum: Lacks ribosomes and synthesizes lipids, detoxifies drugs, and carries proteins.
Golgi Apparatus
- Modifies, sorts, and packages proteins and materials from the endoplasmic reticulum for storage or secretion.
Lysozymes
- Membrane-bound sacs containing enzymes that break down food substances and waste materials.
Centrioles and Vacuoles
- Centrioles: Aid in coordinating cell division in animal cells.
- Vacuoles: Store water, food, enzymes, and waste materials.
Cytoplasm
- A jelly-like substance that holds organelles in place.
Mitochondria
- Known as the powerhouse of the cell, they convert chemical energy from food into usable energy.
- Composed of an outer membrane and an inner membrane with folds known as cristae.
- Responsible for cellular respiration and contain their own DNA inherited from the mother.
Using a Microscope
- Steps include turning on the microscope, adjusting the light, placing the specimen, and focusing using coarse and fine adjustment wheels.
- Observers can switch to medium and high-power lenses for detailed examination.
Summary of Microscopes
- Microscopes magnify specimen structures, enabling detailed visualization which requires specimens to be focused using adjustment wheels.
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Description
This quiz delves into the fundamental aspects of cells, exploring their discovery, structure, and various types. Understand the unique functions and biochemical organization that define plant, animal, and bacterial cells. Test your knowledge on the smallest building blocks of life!
