All the cells in a _______ are diploid; all the cells in a _______ are haploid.
The sporophyte generation begins with a ______ and ends with a ______; the gametophyte genation begins with a _____ and ends with a _______.
- zygote; spore
- spore; gamete
Fertilization triggers the transition from ______ to ______ generation; meiosis triggers the transition from _______ to ______ generation.
- gametophyte; sporophyte
- sporophyte; gametophyte
- primary function: growth, repair & development
- two "daughter" nuclei produced
- daughter nucleus have the same number of chromosomes as parent nucleus
- daughter nuclei is genetically identical to original cell
- daughter nuclei are genetically identical to each other
- Primary function: makes spores in plants; gametes in animals
- Four "daughter" nuclei produced
- Half the number of chromosome found in the parent nucleus are in each daughter nucleus
- Daughter nuclei are not genentically identical to original cell and are not genetically identical to each other
Having half the number of chromosomes found in the diploid spore mother cell.
Meiosis in animals
Only occurs in the gonads -- the diploid ovary and testes that produce haploid eggs and sperm
Both meiosis and mitosis are usually followed by ______.
the division of the cytoplasm
the offspring that is produced when a haploid egg and sperm fuse.
Major evolutionary trends
- reduction in the size of the gametophyte
- complex vascular systems
- the seed
Primitive vascular plants produce only one type of spore in one kind of sporangium
water-soaked, slightly rotted plant debris
impregnated with minerals from teh swamp waters
petrified lumps of fossil peat
Which half of the life cycle is dominant, the gametophyte or the sporophyte?
The sporophyte, except for in moss, gametophyte is dominant in moss
How do the sperm in non-flowering plants get to the egg?
The flagella helps it swim
In non-flowering plants, what is the primary mode of dispersal?
By spores, "naked seeds (inside cones)
The green portion of the moss is the ______.
why do mosses usually grow only in moist, shady habitats?
They need water/moisture for sperm to travel to femal gametangia.
Which generation is independent (capable of photosynthesis) in mosses and which one is "dependent" on the other for nutrition?
gametophyte is independent and provides nutrition for dependent sporophyte generation
why don't all the gametophytes have a sporophyte growing from their tops? Are those without sporophytes the "male" gametophytes?
some gamtetophytes are males and others are female and the sporophyte can only grow from the female
what is the primary mode of dispersal in mosses?
how do the gametophytes produce haploid gametes without meiosis?
exponlixis: a sexual reproduction, deregulation of meiosis resulting in mitotic cell division
large, leathery leaves normally found on ferns
Sporophytes on mosses
brownish, hair-like structures growing out of the top of some of the gametophytes
Mosses are ______ that lack _______: they have no true stems.
bryophytes; vascular tissues
underground, creeping stem that roots grow off of
clusters of (spore producing) sporangia, found on the underside of the fronds
part of the sporophyte, along with the fronds, the roots, and the rhizomes
in what sense can ferns be considered "intermediate" between bryophytes and higher plants?
- like bryophytes, ferns produce sexually by making spores rather than seeds
- like higher plants, ferns have stems with vascular tissue
what is the primary method of dispersal in ferns?
wind an water, especially wind
how is water transported in ferns?
ferns are vascular plants with vascular tissue that allow active water transport
why are ferns most common in moist habitats?
they need water to reproduce
not protected inside a fruit
plants with flowers in which sexual reproduction occurs, in which seeds are formed, and from which fruits develop
stalk of a solitary flower
bears sepals and petals
sepals (collectively: calyx)
usually green; protects bud
petals (collectively: corolla)
often pigmented to attract pollinators
- male flower organ
- stalk supporting anther
- produces pollen
- female organ
- often "sticky" to receive pollen
- stalk supporting stigma
- enlarged base that ripens into fruit; contains one or more "ovules" (potential seeds)
how are microspores formed?
Each microspore mother cell divides by meiosis to produce four haploid microspores
are microspores haploid or diploid?
microspore mother cells are diploid, microspores are haploid
The ovary and egg formation
- 1. diploid megaspore mother cell undergoes meiosis and produces 4 haploid megaspores
- 2. three haploid megaspores die, one haploid megaspore left
- 3. single haploid megaspore undergoes mitosis producing 2 identical haploid nuclei
- 4. 2 identical nuclei undergo mitosis and form 4 identical haploid nuclei
- 5. 4 identical haploid nuclei undergo mitosis and form 8 identical haploid nuclei in mature ovule
what is the difference between pollination and fertilization?
in pollination, pollen is transferred in plants enabling sexual reproduction. in fertilization, fusion of gametes produce a new organism