lecture 3 Flashcards
what are bryophytes
nonvascular land plants (mosses, liverworts, hornworts)
what new evidence has come up about bryophytes
in past years bryophytes were not a clade but now they are seen as a clade and are equally related to vascular land plants
what are the main characteristics of bryophytes
- they have NO true ROOTS, STEMS or LEAVES, 2. have no strong support tissue plant body 3. obtain and move water in a undirected fashion 4. they have signaling protein involved in desiccation tolerance 5. have swimming sperm with two tails
what is desiccation tolerance
they can voluntarily dry out and shut down cells to preserve water and open up again when in contact with water
what are the key adaptions for colonization for bryophytes
they live in moist areas, small so they dont need to move water too far, can live on rocks and buildings, small enough to get minerals through diffusion, and have relationship with fungi
what is gametangia
organs that make and enclose gametes an prevent them drying out
what are archegonium
creates female eggs through mitosis
what are antheridium
creates male sperm through mitosis
what is an embryo
young plants contained with a protective structure
sporangium
makes spores through meiosis
what is a gametophyte
haploid adult dominant form of bryophyte
what is a sporophyte
diploid adult , dependent on gametophyte for nutrition, needs water to be splashed to move sperm
what are the three bryophyte linages
mosses, hornworts, and liverworts
what are characteristics of liverworts
- green flat leaflike gametophytes 2. growth occurs at the apex 3. no true stomata so no internal water conduction 4. has unique parallel ridges 5. 2 sperm tails
what are characteristics of liverworts sporophytes
sporophyte has a stalk and a capsule (sporangium), stalk elongates rapidly by cell elongations, they have elaters
what are elaters
assists in dispersal flexible in response to change in humidity
what are characteristics of mosses
erect, leafy gametophytes, have stomata, have cells called hydroids and have peristome teeth
what are hydroids
cells that die and leave a channel through which water can move
peristome teeth
they line the apex of the capsule or sporangium and change shape with humidity and moves spores
what are characteristics of hornworts
the sporophytes look like small horns, the cells contain one chloroplast, and the sporophyte grows from the basal region capable of indefinite cell division, THEY HAVE A SYMBIOTIC RELATIONSHIP WITH CYANOBACTERIA TO FIX NITROGEN
what are characteristics of moss Sphagnum**
the sporophyte capsule pops off, large in ecologically and economically are (good in short summer), the sphagnum removes a lot of CO2 and burns well when its dry, it is used for fertilizer, whiskey, and burning
