Lab 4: Alternation of Generations/Sex in a Dish (Part 1) Flashcards
What is alternation of generations?
a mode of sexual reproduction found in many plants that includes two distinct developmental phases defined by the events of meiosis and fertilization
What are the products of meiosis in alternation of generations?
haploid spores
How many cells are spores?
one
What do spores turn into once they have germinated?
Gametophye
What is the multicellular haploid phase of the plant life cycle?
The gametophyte
What do gametophytes produce?
gametes
Is mitosis or meiosis used for a gametophyte to produce gametes?
mitosis
T or F? The gametophyte also can be used as a site for fertilization.
T
Development of a zygote will end in the creation of what stage of the cell cycle?
Sporophyte
What is the multicellular diploid stage of the cell cycle?
Sporophtye
Which type of plant (NV/V) has gametophyte dominance?
Non-vascular
T or F? Vascular plants have a gametophyte dominant generation.
F
What is the Archegonia?
The female reproductive organ of a plant
What is the Antheridia?
The male reproductive organ of the plant
What is the sporandia?
the structure in which mother spores are held
What are rhizoids?
filament anchors of the gametophyte
What is the chemical used to help the sperm find the egg?
SAAF (sperm activation and attracting force)
What are homosporous spores?
spores that are all the same size and will give rise male and hermaphroditic cells
Why are there so few hermaphrodites and so many male spores?
Because the first cell in an area develops into a hermaphrodite and then sends out a hormone to restrict the growth of more hermaphrodites
what is the hormone released by hermaphrodites?
Antheridiogen
What are the 3 positive effects of lots of sperm and few hermaphrodites in an area?
- increases genetic variability
- increases cross fertilization
- reduces self fertilization
Why is it beneficial to only have a couple hermaphrodites in an area?
reduces competition between the hermaphrodites for resources
Why is it beneficial for hermaphrodite spores to be the first to grow in an area?
gives the hermaphrodite a head start because in the end it will be bigger than its male counterparts
What type of cells are the products of meiosis in plants?
spores
What type of sex cells are the products of mitosis in plants?
sperm and egg (gametes)
What is the ploidy level of spores and what phase of the plant life cycle do they develop into?
n, gametophyte
If there are known to be hermaphroditic spores for a plant will the spores be similar or different in size?
similar
How many cells are in a spore?
one
A single, spore-bearing plant can produce millions of spores. What is the main reason that so many spores are produced?
increased chance of germination
What is a trilet mark?
a scar on a spore showing where its 3 other sibling spores were once connected
why might results for spores number be different than expected based on the serial dilutions performed?
inversions and non-homogenous concentrations
