Plant reproduction L13 Flashcards
Why is it important for plants to reproduce?
Immobility, genetic variation, longevity
What are the pros and cons of asexual reproduction?
Offspring are genetically identical
Plants mature faster than developing from seeds
Disadvantages
Plants vulnerable to environmental change
Offspring are close to parents, increasing competition
What are some methods of Asexual reproduction?
propagation using roots
propagation using stems
propagation using leaves
What are the new traits land plants developed for reproduction
Alternation of generations
Evolution of pollen and seeds
Evolution of flowers
Define alteration of generations in plants
Plants will alternate between gametophyte and sporophyte generations
What is unique about gymnosperm seeds?
They lack endosperms, meaning the are less advanced
What stage (gametophyte/sporophyte) is dominant in mosses, ferns, gymnosperms, and angiosperms
Gametophyte, sporophyte, sporophyte, sporophyte
Describe pollen production
Meiosis produces haploid microspores, which undergo mitosis which produce pollen grains, and is then transferred by male gametophytes
Pollen is unique to each species
What are seeds?
Embryos of gymnosperms and angiosperms that form after fertilization
Why are seeds a very beneficial adaptation?
They remain viable for many years due to low metabolic activity allowing them to survive
Are protected from dehydration
Can be easily dispersed
What are the 4 layers of an endosperm seed?
Female gametophyte (1n)
Embryo (2n)
Endosperm (3n)
Seed coat (2n)
What is the carpel in a flower?
Female gametophyte
ovules arise the megasporangia in ovary
contains stigma, style, ovary with ovules
What is the stamen in flowers?
Male gametophyte = pollen grains
contain sperm which arise in microsporangia in anther (pollen sac)
How many haploid megaspores are produced via meiosis?
4, one megaspore undergoes mitosis to female gametophyte within ovule the other 3 disintegrate
