Terms
What are plasmodesmata?
Distinctive intercellular connections
What are some examples of nonvascular plants (Give 1).
Moss, Hornwarts, Liverwarts
What ecosystems do seedless vascular plants inhabit?
Aquatic and wet terrestrial habitats
Terrestrial
A seed is a mature _______ while a fruit is a mature ______.
Ovule, ovary.
Ovary is the structure that contains one or more ovules. Gymnosperms do not have an ovary and their ovules are exposed to the environment. Both angiosperms and gymnosperms have ovules, which are covered by integument tissue.
What are stomata?
Stomata: Pores that allow gas exchange in photosynthetic tissues.
In bryophytes, is the sporophyte or the gametophyte dominant? Which is dependent on the other (if any)?
Gametophyte is dominant (the main green part you see on the ground). The sporophyte is dependent on the gametophyte (as the sporophyte grows out of the gametophyte)
What are xylem and phloem? What do they conduct?
Vascular Tissue
*Xylem: Conducts water and nutrients from root to shoot
*Phloem: Conducts carbohydrates and nutrients from shoot to root
What happens once a pollen grain lands on an ovulate cone?
When pollen lands on an ovulate cone, it germinates and a pollen tube is formed. The pollen tube digests through the megasporangium, and sperm travels down the tube to fertilize the egg.
Angiosperms go through double fertilization, what does this mean?
The nucleus in the pollen grain of angiosperms will divide by mitosis to create two sperm; the first sperm will fertilize the egg and the second sperm fertilizes the polar bodies to create a 3N endosperm.
What is a cuticle?
Cuticle: Waxy layer that prevents water loss from stems and leaves.
Which group of bryophytes are the most diverse?
Mosses-approximately 12,000 known species
What are the key vegetative characteristics of seedless vascular plants that are not found in seedless nonvascular plants? (Name 3)
*Roots, stems, and leaves
*Branching
*Cuticle
*Stomata
*Vascular Tissue (xylem and phloem)
*Lignin (provides structural support)
What does the microspore develop into? The megaspore?
Microspore develops into pollen grains with male gametophyte inside.
Megaspore contains the female gametophyte (egg); one megaspore in the oval develops into the female gametophyte. Before fertilization, the ovule contains the megasporangium, megaspore, and integuments.
What are three traits that are ONLY found in angiosperms?
*Flowers: increase success of pollination through co-evolution
*Fruits: covered seeds to aid in seed dispersal
*Double fertilization: formation of zygote and endosperm
What are apical meristems?
Localized regions of cell division at the tips of shoots and roots (the plants stem cells)
What is peat moss? How is it used?
Sporophyte dominant
Both independent of one another.
What is a seed? What is pollen?
*Seed: Protects the embryo from desiccation and allow it to be retained and nourished by parent plant
*Pollen: Make gamete that is desiccation resistant-transported by wind or animal pollinators
Describe the reproductive cycle of angiosperms.
Diploid stamen (male) and ovary (female) develop haploid microspore and megaspore respectively through meiosis. Mitosis produces egg and more pollen which will then combine via fertilization. Through mitosis, the zygote develops into a seed surrounded by fruit which will germinate into diploid sporophyte.
Define alternation of generations/
A life cycle that alternates between two different multicellular bodies.
*Gametophyte(n) produces gametes (n) through mitosis
*Sporophyte (2n) produces haploid spores (n) by meiosis
What are some challenges?
Name 2 of each.
*More exposure to sunlight (not filtered by water or plankton)
*Atmosphere with abundant CO2
*Rich mineral soil
*Few herbivores and pathogens
Challenges:
*Desiccation: loss of water to the air
*Providing support for body of the organism
*Aerial parts of organism not in direct contact with water and mineral nutrients
*Reproduction in dry environments
Describe the reproductive cycle of seedless vascular plants.
The diploid sporophyte produces haploid spores through meiosis. Then through mitosis, a haploid gametophyte is produced. The gametophyte produces haploid gametes through mitosis and combine via fertilization and produce a diploid zygote that will develop int the diploid sporophyte.
What traits do conifers have that adapt them to dry environments with short growing seasons? What economic benefits do they provide?
*Evergreen allows them to photosynthesize year round; The needle helps minimize water loss and shed snow. Some have "serotinous" cones-regenerated by fire.
*Economic benefits: Lumber, paper pulp, musical instruments, food source, tannins (leather products)
What is the ecological importance of angiosperms (and the production of fruits)?
Fruit provides more food resources to primary consumers, enabling increased biodiversity and production.