Topic 9 & 10 - Land & Seed Plants Flashcards
Briefly explain Alternation of Generations
- the alternation of haploid (n) and diploid (2n) multicellular body forms
What are the events of evolution in land plants?
- sporopollenin
- cuticle, pores
- embryophytes
- alternation of generations
- apical meristems
- stomata
- vascular tissue
NOTE: #6 and 7 are derived traits, not all plants have
Name some plant adaptations as they moved to life on land ( similar to the events of evolution )
> sporopollenin > cuticle & pores > stomata > embryophytes > vascular tissue > roots > true leaves
What is transpiration?
- loss of water through the form of water vapor
What is pollination?
- transfer of pollen to the part of the seed plant with the ovules
- non-seed plants require water (single-celled sperm)
- the entire male gametophyte is carried inside the pollen grain
What is double fertilization?
- occurs when the pollen tube discharges two sperm into the female gametophyte within an ovule
What is co-evolution?
- mutual evolutionary influence between two-species, they exert selective pressure on each other
- mutualistic relationships
Define Sporopollenin
- a tough polymer
- in charophytes: protects zygote from drying
- in plants: walls of plant spores
- resistant to drying & physical stress
Define Stomata
- pores in the epidermis of leaves and other photosynthetic organs
Define Apical Meristems
- undifferentiated tissue from which new, differentiated cells arise
- simple in non-vascular plants and more complex in vascular plants
Define Vascular Tissue
- contains xylem (dead cells) and phloem (living cells)
Define Lignin
- complex strengthening polymer
- important in the formation of cell walls
Define Cuticle
- waxy cuticles on the epidermis that are waterproofing and provide protection from microbial attack
Define Mycorrhizae
- mutual symbiotic relationship between the fungus and a plant’s root system
Define Seed
- embryo
- range in size (depends on the amount of gametophyte - derived food)
- tough coating so the tiny embryo is protected
- travel by air, water, and animals
Define Endosperm
- tissue produced inside the seeds of most flowering plants following fertilization
- triploid
Define Pollen
- pollen grains coated with sporopollenin
- ability to withstand drying, UV, and physical damage
- pollen is important since male gametophytes have to disperse to pollinate and then fertilize the ovule
Define Sporophyte
- diploid multicellular stage in the plants’ life cycle
- develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm
Define Gametophyte
- haploid multicellular organism that develops from a haploid spore that has one set of chromosomes
- sexual phase in the life cycle of a plant
Define Flower and Fruit
flowers: contain stamens (microsporophylls) and carpels (megasporophylls)
fruit: mature ovary containing seeds, protects dormant seeds and aids in dispersal
Benefits and Costs of plants living on land
benefits: sunlight, spacious, more CO2, less competition
costs: reproduction, support (staying upright), obtaining resources, and maintaining moisture, UV rays
Why are coastal areas important for the evolution of terrestriality in land plants?
- provides a water medium to complete the life cycle of plants, for example, bryophytes
Why is the evolution of plants more accurately described as an adaption to life “in the air” rather than “on land”?
since most of the plants parts are above the ground, there were more adaptions to the air environment and being able to withstand drying out and UV
What are the characteristics of the first land plants?
- non-vascular
- short roots
- most likely mosses