Biology Unit Exam Flashcards
3 main points of cell theory
-all living things, or organisms, are made up of cells and can be unicellular or multicellular
- cells are the fundamental unit of life, and all cells contain genetic information which allows them to carry out these functions, and are capable of reproduction
-all cells are produced from other cells through cell division, a concept referred to as biogenesis
What is spontaneous generation abiogenesis?
the belief that living organisms arose from non-living entities
Who disproved abiogenesis?
Louis Pasteur with his experiment that involved a beaker and a tube. There is now evidence of MICRO-ORGANISMS!
what are organelles and what is an example?
the non-living part of the cell that has a specialized function which continues to the overall functioning of the cell.
ex. the nucleus
what is a cell and what do they form?
cells are the basic unit of life
they form tissues/stem cells
what is a tissue and what do they form?
they are made up of cells
work together to form organs.
what are organs and what do they form?
made up of tissues
work together to form organ systems
what are organ systems and what is an example?
they are groups of organs working together to make the body function
ex. the cardiovascular system
what did Hans and Zacharias Janssen invent?
-in 1595 they made a microscope which had an eyepiece and a lense
-20x the original size
what did Robert Hooke invent?
-in 1665 he made a three lense system with a light “cell”
-he described what he saw under the microscope
what did Antoni van Leeuwanhoek invent?
- in 1670 he made a simpler design with a higher magnification
-moving cells are called “animalcules”
what does the resolving nosepiece do?
holds up the objective lenses
what do the stage clips do?
they hold the slide in place
what do the objective lenses do?
they have three levels of magnification used to better view the specimen
what does the stage do?
where the slide is placed for support and viewing
what does the diaphragm do?
it regulates the amount of light on the specimen
what does the light source do?
provides the light to view the specimen with more clarity
what does the base do?
supports the entire microscope and is used to carry the microscope
what does the switch do?
turns the light on and off
what does the fine adjustment knob do?
makes the image sharper and clearer
what does the course adjustment knob do?
moves the stage up and down
what does the arm do?
supports the nosepiece and body tube
what does the body tube do?
supports the ocular lense
what does the ocular lense do?
observe the specimen by looking through
what is field of view measured in?
micrometres (um)
how do we calculate size of specimen?
size= field diameter/fit#
why do we use staining/oil immersion/dark field illumination?
to better view the specimen
what is a prokaryotic cell?
DNA is naked and circular
usually no introns
no nucleus*****
not membrane-bound
70s ribosomes
binary fission
haploid
1-5 um
ex. archaea and bacteria
what is a eukaryote cell?
DNA is linear and bound to protein
usually has introns
has a nucleus
membrane-bound
80s ribosomes
mitosis/meiosis
diploid or more
10-100 um
ex. plants, animals, fungi, protists
what does the nucleus do?
controls all cellular activity and is where DNA is stored
what do the lysosomes do?
digest down waste and other foreign particles
what does the smooth ER do?
makes lipids for delivery out of the cell
what does the goldi apparatus do?
involved in secretion, receives stuff from the ER’s
what does the rough ER do?
makes proteins for delivery out of the cell
what do the ribosomes do?
translates mRNA into sequences of amino acids
what does the cytoplasm do?
jelly-like material found inside the cell that holds everything in place
what does the cell membrane do?
controls the movement of materials in and out of the cell
what does the mitochondria do?
where cellular respiration takes place and provides ATP energy
what do the centrioles do?
organize microtubules and help determine the location of organelles
what is the balanced equation for cellular respiration?
C6H12O6+6O2 = 6CO2+6H2O+ATP energy
what is the balanced equation for photosynthesis?
6CO2+6H2O = C6H12O6+6O2
what do the chloroplasts do?
where photosynthesis takes place and contains the chlorophyll
what does the cell wall do?
provides shape and support for the cell
what does the vacuole do?
stores water and other substances
what is in animal cells but not plant cells?
the CENTRIOLES
what is in plant cells but not animal cells?
the CELL WALL, the CHLOROPLAST, and the VACUOLE
define hydrophobic:
pushes water away
define hydrophilic:
pulls water towards it
what makes up the cell membrane and what is another name for it?
a double layer of phospholipid with proteins and other molecules embedded within
a “phospholipid bilayer”
what is the Trilaminar model?
1935
Davson and Denielle
protein layers “sandwich” lipids
disproved by fluorescent tagging
what is the fluid mosaic model?
-1972
-Singer and Nicholson
-proteins embedded in a phospholipid bilayer
define Integral proteins:
span the lipid bilayer, are permanently embedded
define peripheral proteins:
associate with the surface of the membrane, are temporarily attached
what are the roles of these proteins?
J=intercellular Joining
E=Enzymatic activity
T=Transport
R=cell to cell Recognition
A=Attachment
T=signal Transduction
what is cholesterol and what is its purpose?
a type of lipid found in the membrane
it acts to maintain the fluidity of the cell membrane, therefore allowing it to maintain its integrity while it changes shape.
what is diffusion?
movement of solute particles from an area of high concentration to low concentration
what is osmosis?
movement of water molecules from an area of high concentration to low concentration
what is facilitated diffusion?
the transport of substances that cannot cross the membrane by themselves without assistance from a protein.
what is active transport?
energy is required to transport substances from a low concentration to a high concentration
what is a hypotonic solution?
the cell takes in water causing it to swell
what is a hypertonic solution?
the cell releases water causing it to shrink
what is exocytosis?
when molecules are released from the cell
what is endocytosis?
when molecules are taken into the cell
what is pinocytosis?
cell “drinking”
a from of endocytosis which allows cells to obtain molecules dissolved in fluids
what is phagocytosis?
cell “eating”
a form of endocytosis which allows cells to obtain solids
how can you tell how efficient a cell is?
the larger the surface area-to-volume ratio, the more efficient the cell will be
what are some advantages and disadvantages of multicellularity?
(name three each)
ADVANTAGES:
-cells become more specialized so they can perform particular functions more efficiently
-organisms can become larger
-if one cell dies the entire organism is unaffected
DISADVANTAGES:
-takes more energy
-lots of specialized cells
-reproduction of “bad” cells like cancer
what is in the shoot system of a plant and what is its role?
stems, leaves, buds, flowers, fruit
absorbs CO2 and releases O2.
what is the root system of a plant and what is its role?
roots and root hairs
absorbs water and minerals from the soil
what is a meristem and what do they do?
specialized clusters of cells where mitosis occurs
they produce root and shoot tissue
what is the dermal tissue and what is its role?
-it is the outer layer of cells that covers all the non-woody plants
-one cell layer thick
-gas exchange occurs in the lenticels
-protects the plant from disease
-has a waxy coating called the cuticle
what is the ground tissue and what is its role?
-found beneath the epidermis
-provides strength and support
-food and water storage
-location of photosynthesis
what is the vascular tissue and what is its role?
-inner layer
-xylem tissue is specialized in the movement of water and dissolved minerals
-phloem tissue is specialized for the movement of sucrose and other dissolved sugars
where does the gas exchange occur in plants?
in the stomata
explain the process of gas exchange within a plant:
-when the guard cells become turgid, the stomata opens, releasing O2 and absorbing CO2
-transpiration also occurs when the stomata is open
-when the plant is dehydrated, the turgor pressure decreases, causing guard cells to shrink and the stomata to close
what is the palisade mesophyll and what is its role?
-found beneath the lower epidermis
-long, rigid, rectangular cells
-site of photosynthesis
-contains large amounts of chloroplasts
what is the spongy mesophyll and what is its role?
-loosely packed and irregularly shaped
-spaces between those cells allow for gas exchange to occur
what is the xylem and what does it do?
-transports water and minerals
-transported up from the roots
-no sieve plates
-no living outer cells
what is the phloem and what does it do?
-transports sugar
-transports both up and down
-sieve plates are present and are connected to small companion cells
-has living outer cells
what is the role of the cellulose and lignin?
-thick-walled tubes
-support the cell
-transport water from the root
True or False: water is both cohesive and adhesive?
TRUE!
what is positive tropism?
growth of a plant towards a stimulus
what is negative tropism?
growth of a plant away from a stimulus
what is phototropism?
-the growth of a plant in response to light
-controlled by the hormone auxin
what is gravitropism?
the growth of a plant in response to gravity
