Lecture 16 Flashcards
Plants
Are plants motile?
no
Are plants aquatic or terrestrial?
terrestrial
Are plants uni or multicellular?
multicellular
Are plants prokaryotes or eukaryotes?
eukaryotes
Resay all 4 main qualifications for a plant:
- multicellular
- terrestrial
- non-motile
- eukaryotes
What do most plants contain (very important)
contain chlorophyll
What is the nutritional mode of plants (troph)
Autotrophic
What does autotrophic mean?
they can produce their own organic compounds
Through photosynthesis, what do plants produce?
Plants produce oxygen
What is photosynthesis?
synthesis of sugar using light
What do they reduce?
Reduce greenhouse gasses
Name one of the gasses:
CO2 (carbon dioxide)
True or False: Plants moderate climate (shade)
TRUE
What do plants provide for wildlife?
they provide cover/habitat
Plants are WHAT for many organisms?
are a food source
How do plants build soil?
accumulation of dead plant material
Plants can hold 2 things, name them
1) water
2) soil
What do forests prevent?
they prevent soil erosion
What is the most common result of soil erosion?
Soil erosion is often a result of forest clearing
What is forest clearing?
When there are no trees, rainfall lands directly on the ground (rather than through the tree branches)
So how does soil erosion happen then?
more water hits the ground with more force washing soil away
What acts as underground nets preventing extensive soil movements?
Root systems
Name a possible plant Anestor:
green algae (protists)
Both green algae & plants possess 3 things:
- photosynthetic pigments (chlorophyll a & b)
- Both store carbohydrates as starch
- Cellulose – main cell wall component
What is the main difference b/w algae & plants?
Algae adapted for life in water
Plants adapted for life on land
Name all 4 main groups of land plants
1) Bryophytes
2) seedless vascular plants
3) gymnosperms
4) angiosperms
Which 2 groups are dependent on water for reproduction?
Bryophytes & seedless vascular plants
Which 2 groups are INdependent on water for reproduction?
gymnosperms & angiosperms
What do gymnosperms & angiosperms use for reproduction then?
they use wind & animals, etc.
Name one example of a Bryophytes:
mosses (*non-vascular)
Name one example of a seedless vascular plnat
ferns
Name one example of a gymnosperm
conifers
Name one example of an angiosperm
flowering plants
What is particular about Bryophytes?
No true tissues & NO vascular system
Due to what are bryophytes small size, compact and slow-growing?
due to reliance on diffusion
Do bryophytes have true organs?
no true organs (no leaves, no roots)
what do they rely on to obtain nutrients?
must rely on DIFFUSION
Why does the lack of true organs affect it so much?
because of lack of vascular tissue (SO CAN’T transport water/nutrients)
How are the cells of a moss NOT organized into?
Cells of a moss are NOT organized into tissues
Generally, is their one cell layer thin or thick?
Generally one cell layer thick (i.e. no tissues)
Plants without vascular systems have WHAT?
rhizoids
What are rhizoids?
not roots, they serve as anchors
Give an example of a Peat moss:
Sphagnum
What is peat moss used for today in gardening?
Peat moss is used to retain moisture in the soil
What was peat moss used for in the past as a natural remedy?
used as a natural antiseptic material for wounds, preventing infection.
Who is the “Tollund Man” and where was he found?
The “Tollund Man” is a preserved BODY dated 405-100 B.C. found in peat moss.
What type of environment preserves mammalian bodies well?
Anaerobic acidic Sphagnum bogs.
What compounds inhibit bacterial and fungal activity?
Phenolic compounds and acidic secretions.
What prevents the decay of organic materials?
Resistant phenolic compounds and acidic secretions inhibit decay.
What does Bryophytes NOT HAVE that all 3 others have?
Bryophytes = NO vascular tissue
Seedless vascular plants, gymnosperms and angiosperms YES YES YES
What do Bryophytes require most?
WATER
Finish the sentence: Bryophytes are limited to _______ environments
MOIST environments
Why do they require water?
for fertilization
What do they need for plants to become successful on land?
need a better way of acquiring, moving & retaining water & nutrients
What is one adaptation to Land to help with water retention?
Waxy cuticle
What is the main function of the waxy cuticle?
prevents water loss = prevents desiccation/dryness (waterproofing)
What is another adaptation to land related to gas exchange?
Stomatal system
What is the stomatal system?
stoma/stomata = tiny pores on leaf to facilitate gas exchange
+ guard cells (open & closes) to prevent water loss
To better adapt to land, plants developed WHAT?
tissues!
What are tissues?
group of closely associated cells that work together to perform a specialized or particular function
What do we call tissues used in the movement of water & nutrients?
Vascular tissue (like a circulatory system)
What is the main function of the vascular tissue?
Used to transport water/minerals/sugars from roots to leaves
What are the 2 kinds of vascular tissue?
xylem & phloem
What does xylem do?
it carries water and inorganic nutrients (minerals)
What does phloem do?
carries water and organic molecules (sugar,
amino acids, & other organic products)
Once again, what is the vascular system?
A collection of tissues specialized to transport water and nutrients throughout the plant
Plants are decomposed into 3 crucial parts:
root
stem
leave
What do you know about roots?
- Anchor plants
- Nutrient & water uptake
- Storage
Why do roots have root hairs?
to increase the surface area
What do you know about stems?
- Aboveground structural support for leaves
- Transport material from roots to leaves
What do you know about leaves?
Site of photosynthesis
Why do leaves have large surface areas?
solar collector -> collect more sunlight
The main reason why Flat thin leaves have an epidermal layer (& waxy coat)
reduce evaporation (water loss) & contain stomata (gas exchange)
Name an example of Seedless Vascular Plants
Ferns (a transitional plant)
Why do they still require water?
the Sperm is flagellated therefore still requires water to reach the egg
HOWEVER, there are 2 evolutionary advancements, name them
1) well-developed vascular tissue & plant organs (leaves/roots/stems)
2) Support large upright above-ground parts
Are they less dependent on water?
Yes
Complete the sentence: Therefore not limited to ______ (can grow _______!)
Therefore not limited to GROUND (can grow BIGGER!)
Name a group of sporangium:
Fern Sorus
What do Fern Sorus lack?
they lack seeds
If Fern Sorus lacks in seeds, they must rely on what for dispersal?
must rely on SPORES (like Bryophytes)
Through what process do Ferns go through?
Alternation of generation
Name 3 economic benefits of seedless vascular plants vascular
- fiddleheads (food)
- folk medicine (intestinal worms, licorice
fern: sore throat & coughs) - fronds (basket weaving)
In recap, how are seedless vascular plants MORE advanced than mosses?
thanks to the vascular tissue
Name 3 important factors for seedless vascular plants
- wider range
- greater size (↑ photosynthesis)
- great variety
Where are they still relatively common?
in damp/moist environments
Why do they need to be in damp environments?
sperm is flagellated = must swim to egg
Through the Plant evolution, which ones have SEEDS?
Gymnosperms & Angiosperms
What are seeds and what do they contain?
a specialized structure that contains an embryo
What is a seed coat?
it’s a protective covering for the embryo
Why are seeds important?
Because they are the means of dispersing offspring
In a seed there are 3 important things, name them:
- embryo
- seed coat
- food storage tissue
Why does the seed contain a food supply?
after germination seed nourishes plant embryos until it becomes self-sufficient
What is the shape of a Gymnosperms?
Needle shaped leaves
Give 1 example of Gymnosperms:
conifers like the Christmas tree
Conifers are non-deciduous, what does this mean?
leaves do not fall off all at once, exceptions (i.e. larch) (less shedding)
What do we call those who retain some green leaves year-round?
evergreens
What are perennials?
live year after year (vs. annuals)
What are 2 Evolutionary advancements with Gymnosperms?
1) DO NOT need water for fertilization
2) Produce seeds
What do female cones produce?
eggs
Where do female cones produce eggs?
in ovules
Where is sperm develop?
in pollen grains
What do pollen grains have that facilitates dispersal?
air sacs/bladders
So, how are seeds transferred?
by wind!
What are the step to a female cone to be fertilized?
a male cone releases pollen, pollen is dispersed by wind and fertilizes a female cone to fertilize egg
What does this fertilized egg develop into?
fertilized egg develops into an embryo within a seed
What happens then with the seed?
The seed is transferred/dispersed with wind (wind dispersal)
TRUE OR FALSE: Gymnosperms vascular plants with seeds
TRUE
What do Gymnosperms produce?
Produce wind-borne pollen grains
Production of WHAT (2) are features of conifers that allow for further adaptation to life on land?
production of seeds and pollination
Why do we say that conifer seeds with their embryos are said to be “naked”?
b/c they are not enclosed in anything (no fruit)
Producing naked seeds makes them vulnerable to WHAT? (2)
- environmental influences
- attacked by birds, insects, and other animals
What is the last category of plant evolution?
Angiosperms
TRUE OR FALSE: they are the most diverse and successful group of plants
TRUE
Angiosperms are considered to be the most highly evolved plants, what do Angiosperms produce?
They produce flowers
Why are flowers so important?
b/c they promote fertilization via animals
Why do we say that the seed is no longer naked?
b/c the seeds are enclosed within a fruit
Give a few examples of angiosperms:
green beans, melons, tomatoes, apples…
Name the 2 male parts of a flower
Anther and Filament
What are the male parts called?
Stamen
Name the 3 female parts of a flower
Stigma, Style and Ovary
What are the female parts called?
Pistil or Carpel
Ovules are enclosed within a what?
within an Ovary
Which part of the flower produced pollen?
the anther
Where is the pollen deposited?
on the stigma
How does fertilization happen?
sperm from pollen migrates to fertilize one of the eggs in an ovule
What 2 things happen after fertilization?
- ovules become seeds
- ovary wall thickens
What does the ovary become/develop into?
develops into a FRUIT
What is a Fruit?
A “fruit” is the tissue that surrounds the seed
What do we call those layers that develop from the ovary?
pericarp (aka fruit)
TRUE OR FALSE: The fruit may be fleshy or dry
true
TRUE OR FALSE: the pericarp of some foods may be removed before going to market
TRUE: walnuts and coconuts
Remind me again what happens after fertilization
ovule becomes seed & ovary wall thickens = develops into a fruit
Give an example of a fruit that is not fleshy and sweet
edible Rose hips
What do flowers attract?
pollinators
Give a few examples of a pollinator:
insects & other animals, ex. insects, birds, bats
Why do we want flowers to attract pollinators?
for pollination
How do flowers attract pollinators?
Leaves colorful & offer nutritional rewards (nectar, wax, pollen)
How are fruits dispersed (3) + examples
by wind (tulips)
by water (coconuts)
MANY are used to attract animals (mammals/birds…)
What 2 plant adaptations are used to limit water loss?
- thick cuticle
- fewer stomata + opening of stomata at specific times (only at nighttime to gather and store CO2)
What 2 plant adaptations are used to store water (for water storage)?
- enlarged stems (cacti)
- thicker leaves (aloe)
What 2 plant adaptations are used to take up water?
- deep root systems
- laterally extensive root systems
All of these 6 plant adaptations are useful in what types of climates?
HOT/DRY climates
What are 3 plant adaptations that are useful in WET climates
- thin cuticle & thin epidermis
- air sacs and large flat leaves
- stomata on top of the leave
Why are air sacs and large flat leaves important in wet climates?
air sacs for buoyancy (float/rise due to gravity)
large flat leaves for flotation
What do plants produce that aid in their survival? (2)
produce various hormones/chemicals
What do growth hormones do?
help plants grow & develop
Give a few examples of growth hormones
Auxins, Gibberellins, etc.
Name a toxin that kills/inhibits other organisms.
Allelochemicals
They help the plants survive and allow them to respond to their environment (what does responding to their environment mean?)
Gravitropism, phototropism…
What are auxins?
Auxins are plant growth regulators or hormones that promote plant growth
Do auxins promote growth on the vertical or horizontal axis?
along the vertical axis
Where does auxin accumulation occur in response to gravity?
Auxin accumulates on the lower side of plant tissues in response to gravity.
What effect does auxin accumulation have on stem cells?
Auxin accumulation causes the lower cells of the stem to grow more than those on the upper side.
What is the result of auxin accumulation in stems?
The lower side of the stem grows faster, causing it to bend upward.
What type of gravitropism is exhibited by stems?
Stems exhibit NEGATIVE gravitropism, bending away from the force of gravity.
Where does it produce more auxin? (shoot or root?)
SHOOT produces more auxin than root
Does gravitropism happen in roots too?
YES
Where does auxin accumulate in roots?
accumulates on the lower side of plant tissues in response to gravity
How does it affect the cells?
this causes those cells to grow LESS (than cells on upper side)
How does it inhibit cell growth?
(2 -> lower & upper side)
The Lower side of the root will grow SLOWER AND Upper side of roots will grow FASTER
Is this negative or positive gravitropism?
POSITIVE gravitropism
What do Allelochemicals that some plants produce do that make them toxic to other plants?
Inhibit growth, germination, cell division,
water/nutrient uptake, respiration, etc.
Name a plant that has allelochemical properties
Garlic
How does this allow for many advantages to the plant producing the allelochemical? (3)
- less competition
- more nutrients (water, sunlight, nutrients, space…)
- results in greater survival/success of plant
What is Gibberellins?
GA: plant growth hormone
What are the effects of Gibberellins?
- stem elongation,
- increased internodal length,
- germination,
- flowering,
- fruit ripening,
- breaks dormancy
Why is Gibberellins helpful in dwarf plants?
Dwarf plants don’t produce gibberellin (GA)
Therefore, Application of GA will INCREASE plant growth in dwarf plants
Name a few reasons why products from seed plants are commercially important:
- food
- ornamental plant
- paper
- furniture, lumber
- feed livestock
- musical instruments…
RECAP: what is the most primitive of the plant evolution?
Bryophytes (mosses)
What are considered to be transitional plants?
Seedless Vascular plants (Ferns)
Name 2 seed-producing vascular plants:
Gymnosperms (naked seeds) & Angiosperms (covered seeds)
