Plant Reproduction, Growth, and Development Flashcards
what is the transition to land?
moving gametes and offsprings through air
Air is […] buoyant than water, provides a […] buffer against changes in temperature and ultraviolet radiation, and […] the risk of drying out.
less, poor, increases
key adaptations for terrestrial habitats (4)
- alternation of generations
- production of spores that resist desiccation
- gametes that resist desiccation/mechanical damage
- embryo retained by/nourished by parent plants (embryophytes)
plantae
- algal sister groups of land plants
- chlororphyta
- charophyte
- have one multicellular
what groups are the seed plants?
- gymnosperms and angiosperms
- pollen seeds
what are lycophytes and germs and horsetails
spore dispersing vascular plants
what are the 4 major steps of a life cycle?
- formation of two types of spores
- spores undergo mitosis/meiosis inside sporangia
- pollination
- maturation of fertilized ovule into seed
what are the 2 formations of spores?
male gametophyte = male gametes
female gametophyte = female gametes
which spore undergoes mitosis inside sporangia
female: a single haploid spore develops into female gametophyte
which spore undergoes meiosis inside sporangia?
male: large numbers of haploids spores each develop a male gemotophyte
explain ovule cones
they are basically found in upper branches of gymnosperms, produce spores that become female gametophytes
where do female gametophytes develop?
ovule cones
ovule cones steps
- within each sporangium 1 cell undergoes meiosis to make 4 haploid spores
- 3 spores degrade and 1 becomes gametophyte through mitosis
- one or more haploid cells of gametophyte forms egg
- gametophyte remains attached to sporophyte
what does a pollen represent
- male gametes/gametophyte
what is a sporonpollenin
it protects the spores/pollen from uv radiation and desiccation when its in the air or water…
sporophyte
a plant that makes spores
which is a diploid multicellular plant
gametophyte
it is a haploid multicellular plant that produces games aka a plant that makes gametes
how do bryophytes release sperms
usually though raindrops and they go into the female gamete (reproductive system) and coat moist surfaces
what do raindrops do
they signal the presence of surface water and their impact can splash sperm farther than they can swim on their own
for bryophyte where and how does a sporophyte grow?
in the original female gamete (gametophyte), grows from the egg after fertilization
when do sporangia of bryophytes usually release?
their spores only release when the air is dry
what is the significance of the multicellular sporophyte?
it enhances the ability of plants to disperse on land
xylem and phloem develop only in?
sporophyte
ferm gametophytes are usually?
unisexual
unisexual
typically each individual produces only one type
how do fern gametophytes release sperms
through moist environment through a film of water, following chemical signals produces by egg
what do the union of male gamete and a female gamete produce? ferns
zygote (2n)
what is a gamete
they are short-lived and require hydration, they can also fuse with another gamete to form a new individual
what is a spore
a spore does not require hydration and is long-lived, and they can survive air because of sporopellenin, a spore once dispersed can grow into a new individual
4 major stages in the life cycle of seed plants?
- spore formation
- gametophyte development
- pollination/feriltzation
- seed maturation
what happens in stage 1. spore formation
2 types of spores are formed, each produced in different sporangia
which plants are unisexual
seed plants gametophytes
pollen tube
it is a tube that grows outwards from the pollen which allows the male gametophyte the sperm to the egg.
why is dormancy good
they delay germination events conditions for growth are favourable to help prevent them from negatives
how do moss gametophytes release sperm
they release when it is moist because of raindrops, so they stick to the female gametophytes
