Biology Chapter: Microscope Parts & Cell Theory

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Questions and Answers

What is the primary function of the diaphragm in a microscope?

To magnify the image

To support the object being observed

To hold slides in place

To control the amount of light reaching the object (correct)

What did Redi's experiment with meat in jars demonstrate?

Life comes only from existing life (correct)

Microorganisms can spontaneously generate

Life can emerge from non-living matter

Sealed environments promote life

Which scientist is known for first observing single-celled organisms and naming them animalcules?

Schleiden

Pasteur

Leeuwenhoek (correct)

Virchow

What does the coarse adjustment knob on a microscope do?

Moves the stage up or down to focus Signup and view all the answers

Which of the following is NOT a point of cell theory?

Cells can spontaneously generate from non-living matter Signup and view all the answers

What did Pasteur's experiment with the S-shaped neck flask demonstrate?

Biogenesis supports the idea that life comes from existing life Signup and view all the answers

What role did Schwann and Schleiden play in the development of cell theory?

They observed that all living organisms were comprised of cells Signup and view all the answers

What did Hooke observe under the microscope that led him to name them 'cells'?

Plant cell walls in cork Signup and view all the answers

What is the relationship between the tonicity of a cell and the tonicity of the solution it is placed in?

They are always opposite. Signup and view all the answers

What role do root hairs play in plants?

They absorb water and minerals. Signup and view all the answers

Which process primarily drives the upward movement of water in plants?

Transpiration pull Signup and view all the answers

What happens during the day in leaves with respect to gas exchange?

CO₂ is consumed and O₂ is released. Signup and view all the answers

How do guard cells control the opening and closing of stomata?

By turgor pressure in the guard cells. Signup and view all the answers

What is the function of phloem vessels in plants?

Translocate sugars to stems and roots. Signup and view all the answers

What defines phototropism in plants?

Growth towards light. Signup and view all the answers

What is root pressure primarily a result of?

Osmosis in root cells. Signup and view all the answers

What is the main function of the nucleus in a cell?

Controls all cellular activities Signup and view all the answers

What process occurs in mitochondria to produce usable energy?

Cellular respiration Signup and view all the answers

Which organelle is responsible for modifying and packaging proteins?

Golgi apparatus Signup and view all the answers

What is a primary difference between eukaryotic and prokaryotic cells?

Eukaryotic cells contain a nucleus, while prokaryotes lack one Signup and view all the answers

What role do lysosomes play in a cell?

They destroy dead cell parts or invaders Signup and view all the answers

In plant cells, what is the function of chloroplasts?

To convert solar energy into chemical energy Signup and view all the answers

What is the structure of the cell membrane primarily made up of?

Lipid bilayer with proteins Signup and view all the answers

How do carrier proteins function in the cell membrane?

They undergo changes using energy to transport molecules Signup and view all the answers

What is the primary reason for the small size of cells?

To facilitate faster diffusion of substances. Signup and view all the answers

What is the role of guard cells in a leaf?

To regulate the opening and closing of stomata. Signup and view all the answers

Which cellular process is directly responsible for absorbing large solid particles?

Phagocytosis Signup and view all the answers

What does a hypertonic solution do to a cell?

Causes the cell to shrink and shrivel. Signup and view all the answers

Where does photosynthesis primarily occur in plant cells?

Chloroplasts Signup and view all the answers

What is the function of xylem in vascular tissue?

Distributes water and minerals from roots to leaves. Signup and view all the answers

What is the result of a solution being hypotonic to a cell?

The cell swells as water moves into it. Signup and view all the answers

Which layer of leaf tissue is primarily responsible for gas exchange?

Spongy tissue Signup and view all the answers

What is the primary function of the mitochondria in a cell?

Produce energy through cellular respiration Signup and view all the answers

Which organelle is responsible for protein synthesis?

Rough Endoplasmic Reticulum Signup and view all the answers

What is the function of the cell membrane in a cell?

Transports nutrients and waste materials Signup and view all the answers

What distinguishes eukaryotic cells from prokaryotic cells?

Eukaryotic cells contain a nucleus Signup and view all the answers

What is the role of lysosomes within the cell?

Digest waste materials and damaged organelles Signup and view all the answers

Which component of the cell membrane allows for selective transport of molecules?

Channel proteins Signup and view all the answers

What do chloroplasts in plant cells primarily do?

Conduct photosynthesis using sunlight Signup and view all the answers

What type of glioblastoma does the rough endoplasmic reticulum primarily contain?

Proteins for export Signup and view all the answers

Which part of the microscope is primarily responsible for changing magnifications?

Revolving nose piece Signup and view all the answers

What concept did Pasteur's experiment with the S-shaped neck flask help to establish?

Biogenesis Signup and view all the answers

Which scientist first observed cells and referred to them as 'tiny rooms'?

Hooke Signup and view all the answers

What is the main role of the fine adjustment knob on a microscope?

To focus under medium or high power Signup and view all the answers

Which of the following statements about cell theory is incorrect?

Cells can arise from non-cellular materials. Signup and view all the answers

Which observation led Schleiden to propose that all plants are composed of cells?

Structure of cork Signup and view all the answers

What is a key distinction between abiogenesis and biogenesis as defined in early scientific studies?

Abiogenesis supports life arising from non-living matter. Signup and view all the answers

Which scientist observed that all animal cells share the same characteristics as plant cells?

Schwann Signup and view all the answers

What is the primary function of stomata in a leaf?

Facilitate gas exchange Signup and view all the answers

Which type of endocytosis is specifically for taking in large solid particles?

Phagocytosis Signup and view all the answers

What occurs during the process of exocytosis?

Vesicles fuse with the membrane to release particles Signup and view all the answers

Which tissue type in a leaf is primarily responsible for photosynthesis?

Palisade tissue Signup and view all the answers

What happens to a cell placed in a hypertonic solution?

It shrinks due to water loss Signup and view all the answers

Which component is responsible for transporting sugars within a plant?

Phloem Signup and view all the answers

Which statement best describes the role of the cuticle in epidermal tissue?

Prevents evaporation Signup and view all the answers

Why is it advantageous for cells to be small?

To enhance diffusion efficiency Signup and view all the answers

What causes root pressure in plants?

Osmosis as water moves into root cells Signup and view all the answers

Which of the following statements about xylem is accurate?

Xylem is responsible for transporting water and dissolved minerals Signup and view all the answers

How does sugar move through phloem vessels?

Using active transport and stored energy Signup and view all the answers

During the night, a plant primarily consumes which gas for respiration?

Oxygen (O₂) Signup and view all the answers

What mechanism helps water move up a plant stem against gravity?

Transpiration pull and cohesion Signup and view all the answers

What role do guard cells play in plants?

Opening and closing stomata based on turgor pressure Signup and view all the answers

Which type of plant response to gravity is referred to as gravitropism?

Growth in direction of gravitational pull Signup and view all the answers

Which property of water allows it to move through plant structures such as xylem and phloem?

Adhesion and cohesion properties Signup and view all the answers

Study Notes

Microscope Parts

Tube: Holds the eyepiece and lens at the proper distance
Revolving Nose Piece: Rotating disk holding three lenses, changes magnification
Objective Lenses: Magnify 4x, 10x, and 40x
Stage Clips: Holds slides in place
Diaphragm: Controls the amount of light reaching the object
Light Source: Shines light through the object
Ocular Lens: The lens you look through, magnifies 10x
Arm: Connects the base to the tube, used for carrying
Stage: Supports the object
Coarse Adjustment Knob: Moves stage up/down (focus); avoid on high power
Fine Adjustment Knob: Focuses object under medium or high power

Cell Theory

Cells are the smallest functional unit of life
All organisms are composed of one or more cells
All cells are produced from other cells
Abiogenesis: The idea that life could arise from non-living matter
Biogenesis: The idea that living organisms only come from other living organisms
Redi's experiment: Demonstrated the idea of biogenesis (non living meat in a sealed jar had no maggots)
Pasteur's experiment: Further disproved abiogenesis (meat in an open jar had maggots, an open jar with a curved neck had no maggots despite having the same air)

Parts of a Cell

Basic unit of life, performs;
- Obtain food/energy
- Reproduction
- Convert energy
- Carry out chemical reactions
- Eliminate waste
- Growth

Brain Organelles

Eukaryotes: Multicellular, nucleus, organelles
Prokaryotes: Single-celled, no nucleus, no organelles
Organelles: Internal structures that carry out specific functions in a cell
Nucleus: Controls all cellular activities, materials exit through nuclear pores; surrounded by the nuclear envelope.
Nucleolus: Ribosome production region
Cell Membrane: Protective barrier, transports materials
Rough ER: Attached to nucleus, has ribosomes, produces proteins
Smooth ER: Attached to RER, no ribosomes, produces lipids
Golgi Apparatus: Packages/sorts proteins from RER, flat disc shaped sacs
Vesicles: Transport substances through the cell
Lysosomes: Contain digestive enzymes, destroy dead or bad parts or invading bacteria

Cell Membrane Properties

Phospholipid Bilayer: Two layers; hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails
Integral Proteins: Span the membrane
- Channel Proteins: Always open, allow ions and water to flow freely
- Carrier Proteins: Open/close to carry large molecules (sugar/fats)
Peripheral proteins: Attach to membrane, temporarily provide general support
Carbohydrate chains/marker molecules: Extend from the membrane, allow other cells to identify them
Cholesterol: Lipid; helps maintain membrane flexibility/spacing

Cell Membrane Transport

Passive transport: High to low concentration, no energy (moves down the concentration gradient until reaching equilibrium)
- Diffusion: High to low concentration through cell membrane
- Facilitated diffusion: High to low concentration using integral proteins (carrier or channel)
- Osmosis: Water moves high to low concentration
Active transport: Low to high concentration, uses energy (moves against the concentration gradient)

Water and Sugar Transport in Plants

Water:
- Adhesion: Attraction of water to other substances
- Cohesion: Attraction of water molecules to each other
- Capillary Action: Ability of water to cling to a surface
- Water moves up the xylem, root hairs and osmosis increase water absorption, and active transport increases the absorption of minerals
- Transpiration Pull: Evaporation of water from leaves pulls more water up the xylem
Sugar:
- Sugars move downwards through the phloem
- Phloem: Living cells (sieve tubes) connected by sieve plates

Gas Exchange in Plants

Stomata: Allows for the intake of carbon dioxide and the release of oxygen (during the day); water loss via transpiration
Guard cells: Surround stomata, regulate opening/closing of stomata via turgor pressure
Lenticles: Lens-shaped openings, gas exchange in woody plants.

Plant Growth Responses

Tropisms: Plant responses to stimuli
- Phototropism: Growth towards or away from light
- Gravitropism: Growth towards or away from gravity
Nastic responses: Plant responses to touch

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Description

This quiz covers essential components of microscopes and the fundamental principles of cell theory. Understand the structure of microscopes and the significance of cells in living organisms. Test your knowledge on how these concepts are interrelated in the study of biology.