Lab 3 Flashcards
what is red algae?
mostly marine & multicellular & macroscopic. source of carrageenan (stabilizing agent for foods, etc).
- one group is coralline algae - incorporates calcium carbonate in cell walls & important for coral reefs. have large number of chloroplasts, chlorophyll a, and phycoerythrin (color pigment)
what is green algae?
one major group is chlorophytes. these include many marine & freshwater & terrestrial. have several forms: single cells to organisms that are multicellular (sea lettuce), filamentous (Spirogyra), solidarity (Chlamydomonas), or colonial
- when occur in large numbers, microscopic can be seen. pigments are chlorophyll a and b, store starch, and have cellulose
what is an example of marine multicellular algae?
Ulva (sea lettuce). has large but very thin blade and moves easily in shallow water. has diploid and haploid
what are the parts of plants?
cuticle: waxy outer covering that protects them from desiccation
stomata: pores in cuticle & provide opening for exchange of gases
cell wall: structure & lignin/secondary growth also provide structure
vascular tissue: xylem and phloem that transport water & minerals & products of photosynthesis
spores and seeds (Gametangia & sporangia are structures that protect gametes and spores)
what is example of nonvascular seedless plant?
mosses. they have chloroplasts, chlorophyll a & b, store starch, and cellulose
- are terrestrial, small, highly dependent on water, green thalli (leaf-like structure) are best known & these are gametophytes - dominant generation. separate sexes and male (antheridium) and female (archegonium)
how does fertilization take place in moss?
sperm flagellated but only way a sperm can get to an egg is if water in the form of raindrop carries it there. once close to archegonium, flagella help sperm to get to egg. once fertilization take place & diploid zygote formed, zygote undergoes mitosis & grows into stalk-like structure that has capsule. portion of plant called sporophyte & grows out of female gametophyte. cell in capsule undergo meiosis and resulting haploid cells become spores. capsule dries & tiny spores released
what is example of seedless vascular plant?
fern. have chloroplasts, chlorophyll a & b, store starch, and cellulose. have vascular tissue (tracheid- specialized cell found in all vascular plants)
what is the lifecycle of a fern?
spores produced on underside called sorus. sorus is cluster of sporangia (structure in which spores are formed by meiosis). spores haploid, and when sorus dries, it bursts and spread spores. spores grow by mitosis into gametophyte stage. grows into prothallus -> archegonia and antheridia grow on underside of prothallus -> fertilization into diploid zygote
what is a seed?
embryonic sporophyte that is packaged with nutritious material and surrounded by seed coat
- used in gymnosperms and angiosperm
what is gymnosperm?
include cycads and ginkgos, and conifers (pines and firs)
- sporophyte dominant (tree) -> male cone produce microspores and female produce megaspores -> pollen grow down to meet ovule to grow zygote
what are angiosperm?
flowering plants -> flowers have unique double fertilization and seeds are produced within fruits
what is double fertilization?
two sperm cells enter ovary via fertilization tube that grows from pollen grain. one sperm fertilizes egg, forming diploid zygote; other sperm fuses with two haploid nuclei from central cell, forming triploid endosperm -> zygote develops and uses endosperm as source of nutrition -> ovary surrounding ovule develop into fruit -> cotyledons (seed leaves) absorb endosperm and provide nutrient to plant
what do seeds have?
nutrients and seed coat that protect seed from desiccation (drying out) -> seed coat has be roughed or broken for germination
what are the different seed dispersal?
wind, animal, water, forcible discharge
