C3.0 Flashcards
multicellular organisms
contain specialized cells that perform special functions (tissues, organs, organ systems)
small surface area to volume ratio
longer life
plant organization : cells
perform a specific job
plant organization : tissues
group of specialized cells working together
plant organization : organs
tissues contributing to the same function
plant organization : organ system
group of organs working together
the shoot system
includes stem, leaves, buds, flowers and fruits.
also includes tubers.
contains photosynthetic organs that absorb CO2 and release O2
the root system
everything underground.
also includes aerial roots.
absorbs water and minerals from the soil.
mitosis
process of cell division where once cell divides into two cells.
cell division occurs in growth areas called meristems.
plant structure
cellulose : gives plant cell walls structure
lignin : another supportive material found in plants
dermal tissue (epidermis)
found on the outside of herbaceous plants (non-woody)
one cell thick.
produces a cuticle: a waxy covering to protect the plant from water loss & insect attack.
involved with matter and gas exchange
ground tissue
layer beneath the epidermis.
responsible for photosynthesis and food and water storage.
makes up most of the body of the plant.
some cells are tightly organized along the surface to gain aces to sunlight for photosynthesis. some cells are loosely packed to allow for storage of gases.
vascular tissue
responsible for the transportation of materials
xylem : moves water and dissolved minerals from the roots up to the rest of the plant.
phloem : distributes food and other sugars from the leaves to the rest of the plant
vascular bundles are visible on the underside of the leaf
xylem tissue
moves water and dissolved minerals.
* movement from roots to stem and leaves.
transports water and nutrients for photosynthesis.
made of long individual cells which grow holes at each end and fuse like a long straw.
xylem cells die, but leave their cell walls intact, forming a transportation network
phloem tissue
moves dissolved sugars (food)
formed with long individual sieve tube cells.
perforated ends and sides to allow transfer of nutrients by osmosis.
* companion cells located in the phloem tissue use ATP to move and transport nutrients from the source (leaves) to the sink (other parts of the plant)
photosynthesis
the leaf is a collection of tissues working together to carry out photosynthesis. the purpose of photosynthesis is to create energy.
Water + carbon dioxide -> glucose + oxygen
** 6H2O(l) + 6CO2(g) -> C6H12O6(aq) + 6O2(g)
cellular respiration
glucose + oxygen -> carbon dioxide + water + energy
C6H12O6 + 6 O2 -> CO2 + H2O + energy
chloroplast
plant cells have organelles called chloroplasts which contain a green pigment called chlorophyll.
cells containing chloroplasts are found in the ground tissue.
light energy is absorbed by chlorophyll and turned into chemical energy (food for the plant)
chloroplast : accessory pigments
chlorophyll is not the only pigment to capture light energy.
accessory pigments help protect the plant and capture the most energy possible.
when temperatures get colder in the fall chlorophyll disintegrates revealing the other pigments underneath.
photorespiration
the two processes together.
neither process can occur without the other
entry of gases into the leaf
air enters plant cells through passive diffusion.
guard cells open into ground tissue to allow for efficient gas exchange.
movement of gas depends on the concentration gradient.
stomata
the majority of stomata on a leaf are found on the underside of the leaf.
depending on conditions the guard cells will open or close.
* stomata must be open for gas exchange
* proper regulation of opening/closing is important for the survival of the plant.
opening the stoma
light hits the top of the leaf, this stimulates potassium ions to enter the guard cell by active transport.
there is now a higher concentration of K+ ions inside the cell, the cell is in a hypotonic solution.
water from the ECF flows into the cell by osmosis. cells become turgid which causes them to change shape and form an opening.
the stoma is now open
closing the stoma
when sunlight is no longer available, K+ is no longer pumped by active transport.
K+ diffuses back out of the guard cells along the concentration gradient. with more K+ ions in the ECF, the guard cells are now in a hypertonic solution.
water flows out of the guard cells by osmosis. the cells lose turgor pressure, become limp and close the stoma.
transpiration
all gas in the leaf is a dissolved into the cells by dissolving in a thin film of water.
this thin film of water causes plants to lose water vapor.
this water loss is called transpiration
adapting to environmental conditions
stomata are sensitive to environmental conditions.
- colour
- leaf size
- cuticle
unicellular organisms
all life processes occur in a single cell.
large surface area to volume ratio.
short life
palisade tissue cells
(ground tissue)
found directly below upper epidermis.
long rigid rectangular cells tightly packed together.
responsible for photosynthesis
spongy mesophyll tissue
(ground tissue)
between palisade tissue cells and lower epidermis.
loosely packed with space in between.
maximized diffusion of gases.
lenticels
while most gas exchange occurs through the stomata, openings through the bark of woody plants also allow entry of gases.
these “slashes” on the tree bark are called lenticels
cohesion
water molecules are attracted to each other.
when one water molecule rises up the xylem tube, it pulls other water molecules with it.
adhesion
since water is polar, it attracts itself to molecules of other substances.
water molecules “stick” to other substances.
in a plant, water molecules would adhere to the walls of the xylem
root pressure
plants actively transport minerals into the root cells. as a result, the root becomes hypertonic to its surroundings causing water to follow.
the water moving into the roots creates root pressure. as water moves into the roots, it pushed other water molecules up the xylem tube.
transpiration pull
refers to the pulling of water molecules up the plant by the vacuum created by transpiration.
this pull is primarily responsible for bringing water from the xylem into the ground tissue.
transpiration depends on temperature
pressure-flow theory
the movement of materials in and out of the phloem
phototropism
refers to the tendency of a plant to grow toward the light.
photo = light , tropism = response to stimuli
stems show positive phototropism because they grow towards the light.
roots show negative phototropism because they grow away from the light.
darwin’s experiment on phototropism
five different trials :
TRIAL 1 : the control
the plant in trial 1 was not altered in any way.
result : the plant bent towards the light
TRIAL 2 : tip removed
result : the plant did not bend
TRIAL 3 : tip covered w/ opaque cap
result : the plant did not bend
TRIAL 4 : tip covered w/ transparent cap
result : the plant bent towards the light
TRIAL 5 : base covered by shield
result : the plant bent toward the light
DARWINS CONCLUSIONS :
phototropism occurred most in the cells in the tip of the plant, which could most readily access the sun’s energy.
boysen-jensen’s experiment
boysen-jensen snipped off the tip of the seedling and paint gelatin on the end, then put the tip on - the seedling followed the light. he then snipped the tip and placed a piece of thin mineral called mica in between the top and the seedling - no phototropism was observed.
Peter boysen-Jensen hypothesized that whatever was responsible for communication between the tip and the seedling must be able to diffuse through gelatin but not mica
area of elongation
the area of the plant which bends toward the light was called the area of elongation because the cells on the “dark side” of the stem became longer, causing the plant to bend
auxin
a hormone which is produced in a plant and then transported to cells which elongate upon its contact
gravitropism
plants also respond to another stimulus : Gravity
stems show negative gravitropism because they grow against gravity (upwards)
roots show positive gravitropism because they grow with gravity (downwards)
biome
a large geographical region with particular climatic conditions.
considered to be open systems
six biomes
tundra taiga deciduous forest grassland rainforest desert
tundra
most is found around the arctic circle. number of daylight hours vary greatly, receives little to no insolation. ice and snow cover most of the tundra year-round, known as permafrost. region has a high albedo.
** cold and dry **
taiga
found just south of the tundra. also called boreal forest due to the abundance of conifer (evergreen) trees.
** warmer and wetter ** than tundra
animals are inactive during winter / colour changing coats
deciduous forest
distinguished by trees that lose their leaves in the fall. found on N & S America, Asia, Europe and Australia. very distinct winter and summer seasons. same precipitation as taiga but with warmer temperatures.
grassland
occur on all continents, different names such as prairie or savanna. temperature range varies greatly however it always receives little precipitation.
rainforest
warmest and wettest biome. richest variety of plants and animals. plants grow year-round
desert
little plant life, high insolation. hot during the day, cold at night.
climatographs
summary graphs that describe the average temperature and precipitation for a given region each month. horizontal axis is divided by month, precipitation and average temp is marked on the vertical axes
biosphere
refers to the thin layer of earth that has condition suitable for life, includes :
all living things
the physical environment that supports those living things
subdivided into 3 components
atmosphere
lithosphere
hydrosphere
atmosphere
layer of gases that surround the earth. divided into 4 layers based on temperature 1) troposphere 2) stratosphere 3) mesosphere 4) thermosphere
troposphere (atmosphere)
atmosphere layer #1
from 0 - 10 km
temperature 15 - 60 degrees C
stratosphere (atmosphere)
atmosphere layer #2
from 10 - 50 km
temperature -60 to 0 degrees C
* contains most of the ozone layer
mesosphere (atmosphere)
atmosphere layer #3
from 50 - 80 km
temperature from 0 to -100 degrees C
thermosphere (atmosphere)
atmosphere layer #4
from 80 to 300 km
temperature -100 to 1500 degrees C
lithosphere
a.k.a. Earth’s crust - the solid portion of the earth. extends from the earth’s surface inward
hydrosphere
all of the water on earth
weather
day-to-day conditions
climate
average condition occurring over a period of 30 years or longer
climate change
refers to a noticeable change in average temperatures in a region over time
global warming
global warming is happening.
since 1990, the global average temperature has risen by 0.6 degrees C
anecdotal evidence
evidence based on stories people tell. most often qualitative in nature.
instrumental evidence
includes any evidence that comes as a result of measurement. most often quantitative in nature
direct evidence
explicitly indicates global warming is occurring, based on an actual measures change in global temperatures
indirect evidence
evidence that seems to support the idea of climate change but does not involve a direct measurement of temperature.
ex : tree ring analysis, ice core sampling, fossil records & pollen samples
Global Warming Potential (GWP)
the GWP of a gas represents its ability to trap thermal energy in the atmosphere
Carbon sinks
any process that removes carbon dioxide from the atmosphere (photosynthesis)
carbon sources
any process that releases carbon dioxide into the atmosphere (cellular respiration, fuel production)
halocarbons
man-made chemicals used in coolants
Montreal protocol
international agreement signed in 1987 by 182 nations. agreement was made to replace CFC’s with less harmful chemicals.
United Nations framework convention on climate change
agreement to stabilize greenhouse gas emissions cause by human activity. it set out a process for future actions on climate change
Kyoto protocol
in 1998, 161 counties signed an agreement to reduce the production of greenhouse gases. the counties agreed to reduce their emissions to 5% lower than they were in 1990 by 2012
impacts of climate change
as a result of climate change, ecologists predict that we will see a change to the distribution of biomes in Canada.
