CLONING vs SEX in plants - PowerPoint PPT Presentation

Loading...

PPT – CLONING vs SEX in plants PowerPoint presentation | free to download - id: 6ad34-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

CLONING vs SEX in plants

Description:

winter bulb multiplication, as in onions and daffodils ... roots at nodes, like strawberry, spider plants, ferns, and Bermuda grass tillers ... – PowerPoint PPT presentation

Number of Views:28
Avg rating:3.0/5.0
Slides: 19
Provided by: qc03
Learn more at: http://campus.queens.edu
Category:
Tags: cloning | sex | plants

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: CLONING vs SEX in plants


1
CLONING vs SEX in plants
2
Natural methods of asexual propagation in plants
  • winter bulb multiplication, as in onions and
    daffodils
  • tubers storage stems with buds eyes which
    form roots and shoots.
  • rhizomes horizontal stems which form branch
    shoots and adventitious roots at nodes, like
    strawberry, spider plants, ferns, and Bermuda
    grass tillers

3
More cloning methods
  • other stems which may produce adventitious roots
    when they touch the ground, like cacti and many
    other succulents, Forsythia, tomatoes
  • (rare) leaves which produce baby plantlets like
    piggyback plant and Witchs tears
  • unfertilized flowers in some species can produce
    fake embryo clones within sterile seeds in
    blackberries and some varieties of oranges. This
    is called apomixis and is probably more common in
    populations which began as polyploids or
    aneuploids.

4
The main advantages of natural asexual
propagation
  • A plant which has good genes for a particular
    habitat can quickly produce many very successful
    offspring
  • Asexual propagation also produces more offspring
    at a lower average energy cost than with sexual
    reproduction.
  • It produces no wasted offspring like the
    professors brother with bad or risky genes
  • Asexual propagation does not have to depend on
    neighbors or wind or insects for pollination.
  • No STDs

5
The main disadvantage of natural asexual
propagation
  • the offspring have genes which are good only in
    a particular habitat. When the environment
    changes, ALL the offspring will have bad genes.
  • Genetic variability is extremely low in
    populations which are perpetuated asexually.
    New research in water fleas.

6
  • self-pollination selfing both gametes coming
    from the same perfect hermaphroditic monoecious
    plant
  • vs
  • cross-pollination crossing out-crossing

7
cross-pollination crossing out-crossing
  • Advantages?
  • vs
  • Disadvantages?

8
self-pollination selfing both gametes
coming from the same perfect hermaphroditic
monoecious plant
  • Advantages?
  • vs.
  • Disadvantages?

9
self-pollination is a compromise
  • Its better than ____?______
  • But safer than ____?________

10
mechanisms which discourage self-pollination
  • various modifications to attract pollinators
    bright colors, strong odors, landing platforms,
    drinking tubes, nectar, UV bulls-eye designs,
    etc.
  • having female parts above the male parts so that
    self-pollen is less likely to reach the female
    parts
  • having female parts on different flowers like
    cucumbers or on different plants like holly
    (dioecious)
  • having female parts or female flowers maturing at
    different times from male parts like lilies
  • having chemical incompatibilities sort of like
    an allergy to self-pollen like tobacco

11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
dispersal of seeds
  • A related issue less chance of inbreeding within
    siblings.
  • Seed dispersal also lowers the competition with
    parents in perennials and helps the population
    expand its territory.
  • Most of the modifications for seed dispersal
    involve the fruit, which contains angiosperm
    seeds.

16
adaptations for seed dispersal (which decreases
the chance of inbreeding)
  • plants trick animals into carrying seeds off by
    making tasty fruits berries and green beans and
    hooked or sticky fruits beggars lice and
    cockleburs. Sometimes the seed itself is tasty
    and the fruit has hard coats to protect the
    dropped seeds grains and nuts.
  • Plants use wind for helicopters, etc., which are
    usually fruits maple, dandelion but sometimes
    just seeds alone milkweed or nearly the whole
    plant tumbleweed.

17
More FRUITY adaptations for seed dispersal
(which decreases the chance of inbreeding)
  • Some fruits and seeds float coconut some seeds
    or fruits are round to help in rolling away from
    the maternal plant hickory nuts and some are
    nearly arrow-shaped to help them lodge between
    soil particles marigolds.
  • Some fruits dry out, then spring open, flinging
    their seeds away from the parent impatiens
  • but others have a water-activated glue, which
    makes the seeds expand and stick to pebbles and
    soil particles so they wont blow away once they
    find a suitably moist habitat.

18
(No Transcript)
About PowerShow.com