Lecture 15.A Flashcards
what are the 4 types of plants
- moss
- ferns
- gymnosperms
- angiosperms
which plants are not vascular ?
bryophytes (moss)
the plants may have evolved from a group of ___
aquatic green algae (protists)
are green algae categorized as plants?
no
What is a Plant ?
Multicellular, eukaryotic
Cellulose in cell wall
Store excess glucose as starch
Form embryos
Most Terrestrial (sea grasses are aquatic) Most have roots, stems, leaves (algae don’t have) Autotrophic: (almost all) produce own organic compounds
Have adaptations that allow for survival & reproduction on land
what is the most common plant? %?
angiosperms, 87%
GAMETES ARE PROTECTED IN __.
POLLENGRAINS
Organ systems of plants?
shoot (made up of stems & leaves) & root systems
organs of plants?
stems, leaves, roots (additional organs in higher plants)
tissues of plants?
xylem, phloem, epidermis
Almost (vascular ones) all plants have these (vegetative) organs
roots, stems, leaves
function of stems?
Stems: ↑ height of plants & ↑ exposure to light
Transport of nutrients
Support for leaves, flowers, fruits
function of roots
Roots: Anchor plants, nutrient uptake & storage
function of Leaves
Leaves: Site of photosynthesis
↑ surface area exposed to light: ↑ photosynthesis
reproduction organs of angiosperms? (male & female)
Female flowers: ovary (which contain the ovule), stigma, style, and petals
Male flowers: anthers (contain pollen grains), filaments, and petals
reproduction organs of gymnosperms? (male & female)
Female cones contain the ovule (which contains the egg)
Male cones contain pollen grains (contains sperm)
reproduction organs of ferns? (male & female)
Female archegonium, contains a single egg.
The male antheridium, contains many flagellated sperm.
reproduction organs of moss? (male & female)
Female archegonium contains eggs,
male antheridium contains sperm.
function of epidermis
Epidermis: covers plant surfaces
function of vascular tissue
Vascular tissue : transports nutrients
Essential to distribute nutrients, hormones
function of ground tissue
Ground tissue: performs specific functions like photosynthesis, food storage, hormone production
what reactions do plants do?
plants do photosynthesis (need CO2, make O2) & cellular respiration (need O2, make CO2)
which organ in plants is responsible for photosynthesis?
mesophyll
function of xylem
Xylem (made up of dead cells)–water, minerals
function of phloem
Phloem (alive)- sugars, aa, fa, hormones
Rhizoids?
root-like ie anchor them to their substrate, but no vascular tissue here so can absorb water & nutrients, but 1) so do “leaves” & 2) nutrients must be distributed by cell-to-cell diffusion.
how do water and nutrients move in the non-vascular plants?
by diffusion from cell to cell.
Nutrients move between cells by diffusion through __
plasmodesmata (pores)
Benefits to living on land (plants)
Sun not filtered by water and plankton
Great for photosynthesis, but have developed adaptations to protect against UV damage
More plentiful CO2
Nutrient-rich soil
plant challenges (water and on land): Water loss
water: not a problem
land: Plant body, gametes, & embryos can dry out (desiccation) (waxy cuticle & reproductive adaptations)
plant challenges (water and on land): gas exchange
water: by diffusion -gases dissolved in water
land: Reduced due to waxy cuticle. (Stomata)
plant challenges (water and on land): structural support
water: not a problem
land: Gravity may cause collapsing (lignin in vascular tissue)
plant challenges (water and on land): reproduction
water: flagellated (swimming) gametes must find the egg
land: Fertilization: Little water for swimming gametes (some swim, others float thru air or transported by pollinators).
function of waxy cuticle
Protects against
- Water loss by evaporation
- Microbes
function of stomata
Photosynthesis: let in CO2, let out O2
Cellular respiration: O2 in, CO2 out
Transpiration: let out H2O vapor. Close if loosing too much water.
what are stomata
Pores on surface of leaves & stems for gas exchange
Why would a plant die if left outside for several days when it is hot & dry?
stomata will close in order to prevent water loss, will not do photosynthesis, no cellular respiration, because no gas exchange. (no carbs made)
what are Mycorrhiza
the name for a mutualistic association between a fungus & a land plant
what are Rhizomes
underground stem (don’t confuse with rhizoids)
Plant Adaptations to Hot/Dry Climates To limit water loss:
thick cuticle, fewer stomata, opening stomata only at night to gather and store CO2
Plant Adaptations to Hot/Dry Climates To store water:
Enlarged stems for water storage (ex. cacti)
Thicker leaves for water storage (ex. aloe)
Plant Adaptations to Hot/Dry Climates To take up water:
Deep root systems
Shallow laterally extensive root systems
Plant Adaptations to Wet Climates?
Thin cuticle (if any)
Air sacs and large flat leaves for flotation
Increased number of stomata
Plant Adaptations in the cold?
Conical shape & flexible branches shed snow.
Evergreen: more time for photosynthesis*
why does salt kill plants?
salt draws water out of the cells
plant adaptation to salty water?
salt glands that excrete salt from the cells
plant adaptation to nitrogen-poor soil
they become Mixotrophic, so they consume the nitrogen from insects
can photosynthetic plants parasitize other plants?
yes, you can have photosynthetic plants that parasitize other plants.
Aside from plants, what other organisms are producers?
Cyanobacteria Photosynthetic protists (desmids, diatoms, euglena)
how is photosynthesis related to carbon fixation
Carbon fixation occurs during photosynthesis, when CO2 in the air is incorporated (fixed) into sugar (an organic molecule).
Why is nitrogen needed by plants
They need it to make various molecules including, but not limited to, amino acids and nucleic acids.
How is vascular tissue similar to our circulatory system?
Like our circulatory system, it is used to transport nutrients, hormones, and various other chemicals, throughout the body.
why must non-vascular plants live in moist surroundings?
Since they don’t have vascular tissue, they don’t have roots for efficient uptake of water and they must transport their water from cell-to-cell. In addition, they require water for reproduction.
Why would a plant die if left outside for several days when it is hot & dry?
For 2 reasons: 1. It would become dehydrated: water would leave the root cells by osmosis & 2. The stomata would be closed to reduce water loss, preventing the cells in the leaf from doing cellular respiration (so no ATP, cells die) or photosynthesis (if over a long time, plant dies).
What limits the growth of moss as compared to a sycamore tree?
Absence of lignin & vascular tissue
what are the 3 components of a seed
a seed coat, an embryo, and a cotyledon.
