Chapter 26 Flashcards
Plants evolved from ____
photosynthetic algae
What are key traits found in different types of algae?
- Multicellular, eukaryotic, photosynethic autotrophs
- cell walls are made of cellulose
- contain chloroplasts with chlorophyll A & B
What are some of the plant traits that are found in charophytes?
- circular rings of proteins that synthesize cellulose
- flagellated sperm similarly - structured
What is the group of green algae called that exhibit some plant traits? (only found in this type!)
Charophytes
What are 3 reasons its so great to live on land?
- brighter sunlight
- plentiful CO2 in atmosphere
- abundant nutrients in the soil
What 3 challenges made living on land difficult?
- force of gravity
- reliable water source
- drying out
What are the 4 key traits that appear in all land plants but are absent in charophytes?
- Alternation of generations
- Multicellular, dependent embryos
- walled spores produced in sporangio
- apical meristems
What are Gametophyes?
Haploid (n) generation that produces haploid gametes (egg and sperm) by mitosis
How many copies of chromosomes do gametophyes?
1
What are sporophytes?
Diploid (2n) generation that produces haploid (n) spores by meiosis. Formed by the fusion of egg and sperm.
The life cycles of plants alternate between two generations of ___ ___ organisms (gametophytes & sporophytes)
distinct, multicellular
Plants are __ because the embryo is dependent on the parent
embryophytes
The embryo is maintained within, protected by, and nourished by the ___ ____.
female gametophyte
Sporophytes have multicellular organs called ____ which produced ___.
sporangia, spores
The walls of spores contain ____
sporopollenin
What is sporopollenin?
a polymer that protects spores from harsh environments and enables spores to disperse in air without drying out.
What are apical meristems?
Localized regions of mitotic cell division that are found at the tips of booth roots & shoots in plants.
Why do plants benefit from these regions?
Increases a plants exposure to resources
roots - deeper roots to access water and nutrient
height - can reach more sunlight
What are stomata?
pores in epidermis of many plants. closes during hot and dry conditions to prevent water loss.
What is the purpose of stomata? (not the water loss idea)
Since its a waxy cuticle, the pores open and close to allow CO2 & photosynthesis
What is a cuticle?
The waxy outer layer covering the epidermis of some land plants.
What does a cuticle do?
- protection from pathogens, rocks, and debris
- preventing water loss
How did fungi get nutrient from soil if they did not have true roots and leaves back then?
Mycorrihizal relationships - symbiotic associations between fungi and plants.
Fungi are ___ that absorb nutrients from the environment through filaments called __.
hetetrophs
hyphae
