Science C Unit Flashcards
who were the Dutch lens-makers, Hans and Zacharias Janssen?
they invented the first compound microscope in about 1595, using a two-lens system of an eyepiece (ocular lens) and an objective lens. Because it made use of more than one lens, it was called a “compound” microscope. Magnification of this first microscope was about 20x and was significant because it extended the reach of the human eye.
Englishman Robert Hooke developed what kind of microscope?
A three-lens microscope. Is credited with using
the term “cell” to describe empty chambers observed in cork.
Anton van Leeuwenhoek, a Dutch businessman,
developed
Lenses that allowed for greater magnification; up to 250x. Under this magnification, he was the first to see the movement of single-celled organisms as small as
bacteria.
Diaphragm
Allows for control of how much light passes through the specimen. A disk found under the stage.
Base
Provides support for the parts of the microscope, foundation of the microscope, bottom portion of microscope.
Ocular lens (or eyepiece)
Type of lens found in the eyepiece, magnifies the image produced by the objective lens (10X).
Low power (Red)
Allows for the largest field of view
Arm
Can be used for carrying the microscope, holds the lenses the proper distance from the specimen
Revolving nosepiece
used to change objective lenses.
High power (Blue)
This setting allows for observation of the most detail
Magnification
Known as the power of the microscope. Total magnification = (eyepiece)(objective)
Low: (10)(4) = 40x
Medium: (10)(10) = 100x
High: (10)(40) = 400x
Magnification can also be calculated by taking a dimension of the image, such as height (hi), and dividing it by the same dimension of the object (ho). (divide diagram size by actual length)
Example: Calculate the magnification power of a microscope if a 1.4 mm long specimen (object = 0) appears to have a length of 46.3 mm (image = i).
(33X)
READ
stage clips
Used to hold the slide in place on the stage.
Course slip
Placed on top of a specimen that is mounted on a slide
Fine focus
Knob on the side of a microscope that allows for small or final adjustments in focus
Coarse Focus or Adjustment Knob
Allows for initial or large changes in focus. Moves the stage up/down.
Stage
Holds the slide/specimen
Objective lenses
Provide various levels of magnification of the specimen
Light Source
Provides light necessary to illuminate the specimen
Field of view = the entire area that you see when
you look through a microscope
You can use view a rule under the microscope to
measure the diameter of the area that you are
viewing; the field of view, however, the accuracy of
this decreases with increased magnification.
The formula below shows the relationship between
field diameter and magnification:
MHFH = MLFL Where: M = magnification H = high power
F = field of view L = low power
Example: If the low power magnification is 4x, and the
field of view diameter is 4.5 mm, what will be the field of
view diameter for a high power magnification of 40x?
Due to the small size of the field of view, sometimes the
unit micrometer is used. 1 mm = 1000 um.
Describe the process of making a wet mount
First, use tweezers to place your specimen on the slide. then, use a dropper to put a small drop of water onto the specimen. lastly, use tweezers to put the coverslip on top of the specimen. if there are bubbles, press down gently on the coverslip a couple of times until the bubbles are gone
Cell Theory
- All living things are made up of one or more cells and the materials produced by these cells.
- All life functions take place in cells, making them the smallest unit of life.
- All cells are produced from pre-existing cells through the process of cell division.
(that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells.)
describe the process of bringing a sample into focus on a compound microscope
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Function of the cell wall
Found in plants; the cell wall is a rigid frame around the cell that provides strength and support.
Function of Nucleus
The organelle that contains DNA, directs all cellular activities (control center); has pores to allow transport of materials. (Controls cell functioning and reproduction)
Function of Cytoplasm
A gel-like substance inside the cell membrane that contains the nutrients required to carry on the life processes.
Function of Ribosomes
Granules (either floating in the cytoplasm or attached to the endoplasmic reticulum) where proteins are produced.
Function of Lysosomes
Double membrane sacs within the cell that contain strong digestive enzymes. (Vesicles containing enzymes that break down unwanted things in the cell/cellular material). Only in animal cell)
Function of Endoplasmic Reticulum (ER)
A series of tubes extending from the nuclear envelope;
rough ER contains ribosomes, associated with protein
production and smooth ER, without ribosomes, is associated with lipid(fat) production.
Function of Golgi Bodies/Apparatus
Flat disc-shaped sacs involved in packaging substances from the endoplasmic reticulum and transporting them out of the cell. (Bodies which pinch off transport vesicles at the end).
Function of Vacuoles and Vesicles
Sites for storage of nutrients, products of secretion, and water. In plants a large central vacuole swells, increasing turgor pressure and creates support.
Function of Mitochondria
Rod-like structures that are the site of cellular respiration; where chemical energy stored in food is released in a usable form (ATP). (Powerhouse of the cell, creates energy). (Helps to release energy from food through the process of cellular respiration)
Function of tubules
responsible for cell transport
Organelles
Structure in a cell with a specific function
compare and contrast animal and plant cells in terms of their structure and functioning.
Plant cells have a cell wall, but animals cells do not. Plant cells have chloroplasts, but animal cells do not. Chloroplasts enable plants to perform photosynthesis to make food.
Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present. Large vacuoles help provide shape and allow the plant to store water and food for future use. The storage function plays a lesser role in animal cells, therefore the vacuoles are smaller. Animal cells are the basic structural and functional units of animal tissues and organs.
Resolution
Allows one to better distinguish structures that are very close together through improved clarity.
An increase in the number of pixels (dots or squares of
colour ) can produce better clarity or higher resolution in digital images.
Stains are used to
Provide contrast between structures being examined.
A type of microscope that provides greater magnification and resolution than the light microscope is the _____ microscope
electron microscope - produce images called micrographs.
Scientific diagram rules
- Straight printed lines that don’t intercept each other
- Neat writing on the right side (no cursive)
- Include magnification
- There should not be arrows
- Include your name and diagram title
The confocal laser microscope
Used on objects too thick to use light microscopes. A laser beam is directed at different planes to produce “slices” of a three dimensional object.
The transmission electron microscope
pass electrons through a very thin section of stained tissue, providing up to 1 500 000 X magnification
The scanning electron microscope
produce 3D images of surface structures. The magnification is up to 300 000 X
describe the cell as an open system
it exchanges matter and energy within its environment so that it may acquire nutrients, excretes wastes and other cellular products. This is controlled by the cell membrane
describe tonicity; hypertonic, isotonic, and hypotonic solutions and their effects on the movement of materials through membranes (water), including those of cells.
in a hypertonic- water would move out of the cell
the membrane is
selectively permeable to maintain equilibrium/homeostasis
the membrane contains
a phospholipid bilayer and proteins
passive transport
uses kinetic energy, particle movement from an area of higher concentration to an area of lower concentration. Also the movement of substances through the cell membrane without the use of cellular energy.
Active Transport
requires energy to move particles (ATP) which is created through cellular respiration. Particles move from areas of low to high concentration.
Concentration Gradient
A difference in concentration of molecules. No extra energy (ATP) is required to move molecules down (with) a gradient; from an area of high to low concentration. Energy is required to move molecules up (against) a gradient; from an area of low to high concentration.
Diffusion
Type of passive transport; movement of particles from an area of higher concentration to an area of lower concentration through vesicles. Diffusion continues until all particles are evenly spread out; are in equilibrium. The rate of diffusion can be increased by adding energy and increasing molecular movement. (heating or stirring)
Osmosis
the diffusion of water across a membrane that is
permeable to water, but not the solute (semi-permeable). (high to low), (Passive transport).
Tonicity
refers to the concentration of a solution in comparison
to that of another.
Isotonic
= same as cell (Doesn’t change the shape of a cell) equal salt and water concentration
Hypotonic
= less solute, more water (turgid). Causes cell to swell through osmosis.
Hypertonic
= more solute, less water. Causes cell to shrink
Facilitated diffusion
the movement from higher to lower concentration, but with proteins facilitating the movement. (Water-soluble
substance need assistance in the form of a protein channel or carrier protein in order to move across the cell membrane.) (Doesn’t need energy).
Active Transport with Carrier Proteins (protein pump)
Similar to facilitated diffusion, but requiring energy to move molecules from a low to a high concentration.
May bring needed entities into the cell or expel materials from the cell.
Endocytosis
Process by which a cell takes in material by forming a vacuole/membrane around it. Require energy from ATP for the rearrangement of the cell membrane.
Types of Endocytosis: Phagocytosis and Pinocytosis
Phagocytosis involves the intake of larger molecules (cell eating). Pinocytosis is the engulfment of liquid and dissolved molecules (cell drinking).
Exocytosis
Active transport that uses vesicles to remove wastes and cell products from a cell. Requires energy from ATP for the rearrangement of the cell membrane.
Transport Protein
Used to help substances enter or exit cell membrane
Carrier protein
transport protein that changes shape when a particle binds with it. Pump that helps move materials from low to high con.
Channel protein
Transport protein that provides a tube-like opening in the plasma membrane through which particles can diffuse.
Protein pump
capable of pumping out compounds that could pose a threat to the cell.
Phospholipid
Made of a phosphate head and a fatty tail. The head loves water, tail hates water.
(READ) If a cell wants to move a substance from an area with a LOW concentration to an area of HIGH concentration, it needs to use ENERGY to PUMP the substance AGAINST its CONCENTRATION GRADIENT.
This is called active transport and uses carrier proteins and ATP (energy)
Observation from iodine and starch lab
The bag is permeable to iodine, but not to the starch. Starch is a bigger molecule while iodine isn’t so iodine is more permeable
Observation from egg lab
The syrup solution was more concentrated so the egg shrunk. The water solution was less concerned and had more water so the egg expanded
Peritoneal dialysis (membrane tech)
Peritoneal dialysis uses the peritoneal membrane to remove/filter out solutes and water from the body fluids of patients with end-stage renal disease.
Secretion means
substances are produced and discharged from a cell, gland, or organ for a particular function in the organism or for excretion. (refers to exocytosis)
Purification of water by reverse osmosis (membrane tech) (decallination)
Reverse osmosis removes contaminants from unfiltered water, or feedwater when pressure forces it through a semipermeable membrane. Water flows from low water concentration (more solute) to high water concentration (less solute).
Hemodialysis
a procedure where a dialysis machine and a special filter are used to clean your blood. To get your blood into the dialyzer, the doctor needs to make access into your blood vessels.
delivery of materials to cells by liposomes or drugs that target receptor proteins. (synthetic membrane tech)
drug delivery with a membrane
explain how a larger ratio allows for more efficient cellular transport.
Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be. (The greater the SA:V ratio, the more efficient cell transport and transports required will be).
Multicellular organisms
composed of more than one cell, with groups of cells, tissues, organs, and systems carrying out cell processes, including absorption, transportation, and elimination.
tissue
A group of cells that work together to carry out a particular function (I.e. Dermal tissue)
Tissues that work together form
organs
Organs that work together form
organ systems.
There are only 2 organ systems in vascular
plants: 1. Shoot system 2. Root system:
- comprises all of the plant above the ground. Gas exchange occurs. (the flower is used for reproduction, stem transports materials, leaf photosynthesizes and forms sugar.)
- includes all of the underground tissue and any roots rising above ground. Used for storage, structure, sucks up nutrients/minerals from soil.
The leaf is called an organ because
its made up of tissues that all work together for a common function
photosynthesis equation
CO2 + H20 -> C6H12O6 + O2
water molecules that stick together and are alike is known as
cohesion
unalike attraction of water to the xylem is
adhesion
The plant organ whose primary function is photosynthesis
the leaf
Stomata(two) or stoma (what do they do, and how do they do this. what happens when things come and go)?
The pore openings in leaves that allow for gas exchange. Guard cells regulate the exchange of gases by changing their shape to control the size of the stomata. When water moves into the stomata they swell and open. When water moves out, they deflate and close.
The epidermis secretes a waxy substance, which
coats the leaf in a layer called
the cuticle. The cuticle protects the leaf from pests and
disease, as well as preventing dehydration.
Epidermis
The dermal tissue of the leaf (epidermis) acts to protect the leaf, allow gas exchange, and allow light to pass to the ground tissues. covers the exterior of the leaf
Guard cells
Embedded in the epidermis are guard cells which surround openings (stomata).
The mesophyll tissue of the leaf is divided into two types of layers:
- Palisade tissue
- Spongy mesophyll tissue
- cells are long and narrow like columns and are packed closely together. This is efficient for photosynthesis because the cells are close to the upper layer for maximum sunlight exposure, and are full of chloroplasts.
- contains fewer chloroplasts. These cells are round and loosely packed with many air spaces around them allowing for water and gas exchange with the environment.
cellular respiration
Process which results in the release of ATP to drive active transport. The process by which organisms use oxygen to break down food molecules to get chemical energy for cell functions.
xylem
The tissue that transports water throughout the plant by tension (or transpiration pull)
phloem
vascular tissue which is responsible for moving the products of photosynthesis (sugar, glucose)
When a high concentration of solutes in the roots cause osmosis and push fluid up the xylem
root pressure
Pressure exerted against a cell wall by the water that has entered the cell through osmosis
turgor pressure
Diffusion in plants is important because
Diffusion is a very important process for photosynthesis where carbon dioxide from the stomata diffuses into the leaves and finally into the cells.
Osmosis can occur in the soil involved in transporting things to roots true or false
true
Active transport is used in plants
to move the sugar
Lenticels (gas exchange)
The openings/pores in the stems of plants that are involved in gas exchange.
Guard cells and gas exchange
they regulate this gas exchange. The stomata allow for it to happen as they create the gas exchange.
Manipulated/independent variable
What is being changed
Controlled variable
Things that should stay the same and be constant
Responding variable
What is being measured/ observed
Source and sink
Source is where the glucose comes from and it is actively transported to the phloem where it moves to the sink and from there its actively transported to the roots and stored there.
Auxin
a Dutch student, named F.W. Went, isolated auxin. Auxin is a hormone that allows for the plant to respond to stimuli.
Tropisms
If the stem/root is pointing up towards the light, it has positive phototropism but negative gravitropism. If the stem/root is pointing down away from light, it has a negative phototropism but positive gravitropism.
Chloroplasts
Chloroplasts enable plants to perform photosynthesis to make food.
Chlorophyll
the photosynthesis reaction requires the catalyst, chlorophyll, found in chloroplasts. The green pigment of chlorophyll helps for the reaction to occur, but is not used up in the reaction.
stimuli
hh
