Biology 10 quiz 2 Flashcards
what are multicellular advantages
- larger size organism (SA:V)
- variety of specialized cells can perform more complex tasks
- ability to adapt to and thrive in many different environments
multicellular organization:
cells -> Tissues -> Organs -> Systems
cells
smallest basic unit of life
tissues
cluster of cells sharing the same structure and function
organs:
combination of different tissues that work together to perform a specific function
system
combination of organs and tissues that perform a complex function
Plant organization:
plants are specialized into two systems:
- shoot system
- root system
they are further specialized into 3 different tissues:
- dermal tissue
- ground tissue
- vascular tissue
shoot system:
everything above ground (eg. stems, leaves, flowers, fruit, buds)
root system:
everything below ground (eg. roots)
dermal tissue:
- also called epidermis
- outer layer of cells that covers all non-woody plants
- important for gas exchange and water and mineral uptake from soil
what is epidermis mean
“skin”
ground tissue:
- the majority of the plant
- functions: stem for strength and support, roots for food and water storage, leaves where photosynthesis occurs
Vascular tissue:
- important in plant transport
has xylem and phloem
xylem:
-moves water and dissolved minerals from soil to leaves for photosynthesis
- dead hollow cells consisting only of cell walls
- linked end to end, forming long tubes called xylem vessels also known as tracheids
phloem:
-moves sugars produced from photosynthesis from leaves to the rest of the plant
- made of living sieve tube cells joined end to end making continuous ducts called phloem vessels
- controlled by the companion cells
cell specialization in leaves:
leaves contain several types of specialized cells that help with their most important activity photosynthesis
what do all organisms need to function?
energy
where does energy come from and pass down too?
it comes from the sun and is passed down through the food chain
how to do organisms create photosynthesis and cellular respiration
organisms convert suns energy into usable energy throu two important chemical reactions, photosynthesis and cellular respiration
photosynthesis:
-requires light
- light energy is converted into glucose
photosynthesis equation
carvon dioxide + water + light energy -> glucose + oxygen
6CO2 + 6H2O + Energy -> C6H12O6 + 6O2
why does photosynthesis occur only in plants
they have chloroplasts which contain chlorophyll -> traps the suns energy for the reaction
cellular respiration:
- second reaction converts glucose into usable ATP energy
- reaction occurs in the mitochondria in both plant and animal cells
How do photosynthesis and cellular respiration work together
-the two reactions are interdependent
- photosynthesis makes glucose and cellular respiration converts it into usable energy
- animals don’t have chloroplasts so we consume plants to get glucose
Gas exchange in plants
plants use their leaves to exchange gases with the environment
how plants breathe
- air diffuses through the stomata
- CO2 in air dissolves into H2O around cells
- water enters the leaf through the xylem - O2 passes out of cells into air spaces and then through the stomata
-H2O vapour also exits through the stomata(plants try to prevent this from happening)
whats the stomata
an opening in the plant leaf that allows gases to pass through
what do woody plants use for gas exchange
woody plants use lenticels
whats transpiration
-the evaporation of water from leaves
- can cause plants to lose 99 % of the water absorbed by roots
what are guard cells
-guard cells change shape to allow stomata to open or close
-controls the amount of gas exchange and transpiration
how do guard cells control the stomata?
- opening and closing of the stomata is controlled by H2O in guard cells (moves in and out through osmosis)
- H2O moving in creates high turgor pressure forcing stomata open
- stomata close as the amount of H2O in guard cells decreases from transpiration
When doe the stomata and gaurd cells open
most plants open the stomata during the day and close at night to maximize photosynthesis and reduce water loss
control mechanisms of the stomata
- The number of stomata in a plant depends on its environment
-dry = don’t want to lose water = fewer stomata
- humid = water loss inst an issue = many stomata
Vascular system
-series of interconnected tubes to transport H2O, minerals and glucose throughout the plant
- extends from roots through the stems to the leaves
- consists of xylem and phloem
water uptake in roots
H2O and minerals enter plants from roots via osmosis and active transport
root hairs increase SA:V for more efficient absorption of minerals and water
in what kind of organism does water need to be transported over much longer distances
multicellular organisms
what helps transport H2O over large distances
The polarity of water. H2O molecules are polar so they can cling to each other and to other substances
what is cohesion
attraction of H2O molecules to other H2O molecules
- tendency to stick together
- + end of one is attracted to - end of other
what is adhesion
tendency of H2O molecules to stick to other surfaces
how does water move in a plant?
root pressure pushes and transpiration pulls
how does root pressure move water
-root pressure pushes water up
-as minerals build up, more H2O moves into the root
- pressure builds up and forces fluid up xylem (helped by cohesion and adhesion)
how does transpiration move water?
-transpiration pulls
- evaporation of H2O through stomata creates a pulling force
what does facilitated diffusion and active transport pump into the leaf
sugar, minerals, and other nutrients
how does sugar move
moves in phloem from leaves to stem, roots and growing shoots and fruits
what does the movement of sugar into phloem do
pulls H2O molecules in as well, increasing pressure
what does sugar transport cause H2O to do
causes H2O to move from high pressure in leaves to low pressure around the plant
how are sugar molecules transported
sugar molecules are actively transported from sieve tube cells to adjacent cells
whats stimuli
environmental factors that cause an organism to respond
how to plants respond to stimuli
-opening or closing stomata
-branches growing
- leaves drop off
- flowers bloom
what are tropisms
control systems that allow plants to respond to change
- growth movement a plant has in response to stimuli
what does a positive tropism do
grows towards stimuli
what does negative tropism do
grows away from stimuli
what is phototropism
growth of a plant towards light
what are the benefits of phototropism?
helps plants maximize light needed for photosynthesis
what is auxin
a hormone produced in plant tips that changes cells growth rate
in phototropism, stem cells grow at different rates causing…
plants to bend towards the light source
what does auxin do in phototropism
auxin moves to the shaded side of the plant which causes cells on the shaded side to grow longer, forcing the stem to bend toward to the light
growth towards light =
positive phototropism
growth away from the light=
negative phototropism
what is gravitropism
a plants response to force of gravity
positive gravitropism =
roots grow towards or with gravity
negative gravitropism=
stems grow away from gravity (up)
in gravitropism when a plant is placed on its side:
auxin collects in cells on the lower side of the stem causing cells on the lower side to grow longer and the team curves up
- roots grow down towards gravity
what does auxin do in roots?
inhibits cell growth
inthe shoots, auxin stimulates cell elongation and promote growth. In the roots, auxin inhibits cell elongation and thus growth
what does auxin do in gravitropism when the plant is sideway?
auxin collects along the lower side of the stem and slows growth meaning the cells on top grow faster and push roots down
nastic response:
a plant response to touch
circadian reponse(sleep movements):
change in the position of a plant’s leaves according to the time of day
controlled by changes in turgor pressure
what did charles and francis darwin hypothesize/do?
they discovered that the phototropic stimulus (light) is detected at the tip of the plant
what did Peter boysen-jensen discover or hypothesize?
that a chemical signal produced in the plant tip was responsible for the plant bending response at the base
what was F.W. Went’s contribution or conclusion?
confirmed Peter Boysen - Jensens hypothesis that a growth chemical is produced in plant tips
named the chemical auxin
how does auxin work in plants?
stimulates cell elongation by stimulating wall-loosening factors, such as expansins, to loosen cell walls
in what organelle does photosynthesis take place in
chloroplasts
what organelle does cellular respiration take place in
mitochondria
what are the two procucts of photosynthesis
glucose and oxygen
what are the two reactants needed for cellular respiration
glucose and oxygen
what are three products of cellular respiration?
water, carbon dioxide, and energy
what is the one component in photosynthesis that is not recycled and must be constantly available
sunlight
what is the cuticle
a waxy substance that coats cell to prevent evaporation of water from leaf
lower vs upper epidermis
Upper epidermis is mainly involved in water conservation. Lower Epidermis: Lower epidermis is mainly involved in the gas exchange.
palisade tissue cells:
a layer of plant cells containing chloroplasts right below the cuticle and upper epidermis in plants.
spongy tissue cells
- layered just below the palisade tissue cells
- round, loosley packes, and have many air spaces between them
- contain chloroplasts and carry out photosynthesis
whats does vascular tissue contain
xylem and phloem
do photosynthesis and respiration happen at the same time or at different times
same time
during photosynthesis, do plants have a net production or loss of oxygen and carbon dioxide
net production of oxygen and a net loss of carbon dioxide
during cellular respiration do plants have a net production or loss of oxygen and carbon dioxide?
net loss of oxygen and net production of carbon dioxide
the movement of carbon dioxide throughout the leaf is know as…..
passive transport because it travels from an area of high concentration to low concentration
lenticles:
lens-shaped opening penetrates bark so air can diffuse
what do woody plants have to prevent gas exchange with the environment
dead cork cells and cuticles
what is turgor pressure
increase H2O pressure = swollen gaurd cell
explain how the guard cells allow the stomata to open and close
water moves into guard cell increasing turgor pressure and the stomata opens
water leaves guard cell and turgor pressure decreases causing stomata to close
water leaves the plant as…..
vapour
xylem sap
Xylem sap carries soil nutrients (e.g., dissolved minerals) from the root system to the leaves
consists primarily of a watery solution of hormones, mineral elements and other nutrients
what would happen if the column of water within a xylem wessel were to break
it could block the rising xylem sap
why do bubbles form in xylem sap
only the water molecules above the point of the break can be pulled upward
what are two mechanisms in which water can move upwards over long distnaces
pushing and pulling
where are 3 places xylem and phloem tissues found
leaves, roots, stems
are xylem cells living tissues or dead
mostly dead cells in a mature plant
structure of phloem
cylindrical cells joined end to end
is phloem made of living cells or dead
living
what are tracheids
-long hollow cells
- both start as living cells that grow end to end but then their contents die leaving only the cell wall
- fluids pass from one tracheid to the next withing the xylem to move water
where does most of the water uptake occur
tip of epidermal cells because they are very permeable to water
what do root hairs do
increase surface area
where does water go once it is through the root tissue
continues diffusing until it reaches the xylem vessels
how are minerals moved across the root membranes
enter through facilitated diffusion or active transport
palisade mesophyll(cell) vs spongy:
palisade mesophyll cells are elongated and form a layer beneath the upper epidermis and they are tightly packed whereas spongy mesophyll cells are internal to the lower epidermis and are a random assemblage of irregularly shaped cells
arrange the following from most simple to most complex: system, tissue, cell, organ
cell, tissue, organ, system
what is turgor pressure and how is it changed
-the force within the cell that pushes the plasma membrane against the cell wall
- water moving in and out
