Plant Reproduction

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					Plant Reproduction
     How do plants reproduce
► There are two kinds of ways that plants
  reproduce. Do you know what they are???
► The two ways are sexual reproduction and
  asexual reproduction.
► What is the difference between the two????
     Sexual Reproduction in Plants
►   Sexual reproduction in plants is the production of seeds.
►   Producing seeds requires combining a pollen grain and
    ovum (egg).
     This combines genes from 2 different parents and causes the plants
      to be genetically different.
     What are some benefits of genetic variation????
►   Sexual reproduction in seed plants usually involves flowers.
     What function do the flowers serve?????
►   There are other ways that plants reproduce sexually that
    don’t involve flowers but they work in similar ways.
     Pine trees use cones to reproduce. The cones are both male and
      female and serve the same purpose as flowers.
Did you know??? That most flowers have both male
and female parts on the same flower, and often they
are capable of fertilizing themselves.
Plant life cycle: Sexual reproduction
►A  plant starts out as a pollen grain and an
  unfertilized egg.
► This produces a seed through the process of
  fertilization.
► When the seed settles it grows into a
  seedling.
► The seedling grows into a mature plant
  which is capable of producing more pollen
  and eggs, which grow new plants.
The process of fertilization
             Parts of a Flower
► The Stamen is the male reproductive part of the flower. It
  contains the pollen.
► Pollen is responsible for fertilizing the ovum (egg).
► The Pistil is the female reproductive organ.
     At the base of the pistil is the ovary, which contains the ovum.
►   Pollen travels down the stigma where it meets the ovum
    (egg) and fertilizes it.
►   Once the ovum is fertilized the plant concentrates its
    energy on producing a seed.
     The seed must have high energy stores so that the embryo inside it
      can grow until it is developed enough to produce its own food.
     That is why nuts are so high in energy.
Question: What is the function of the petals on the flower????
Answer: The petals may have more than one function, but the most
common function is to attract insects and animals that will move pollen
and fertilize the plants.
         Pollen and pollination
► As we said before pollen is what fertilizes
  the ovum.
► Pollination is the process of fertilization.
► Pollinators are the organisms (birds/insects)
  that help in the process of fertilization.
   Hummingbirds, bees, and other insects get
    pollen stuck to them when they are collecting
    nectar. When the move to the next flower
    some of the pollen will fall off and fertilize the
    that flower.
              Seed distribution
      are dispersed in a number of different ways.
► Seeds
 How many can you think of????
   Some seeds are dispersed by the wind, like dandelions.
   Some fall to the ground and grow only where they fall.
   Some are eaten by animals and when the animals pass
    them they are dropped in the soil.
   Some seeds stick to the fur of animals and are dropped
    in other places. You’ve probably had these types of
    seeds stuck to your shoelaces when you walk through
    the forest.
What is Asexual reproduction???
► Asexual  reproduction is the process of
  reproduction which only one parent is
  required
    Asexual reproduction in plants is also known as
     vegetative reproduction.
    Asexual reproduction creates plants that are
     genetically identical to one another.

 Questions: What are the advantages and disadvantages of creating genetically
 identical plants???
 What ways do you know of that plants reproduce asexually????
Types of Vegetative reproduction
► Runners:   Runners are long stems that grow along
  the surface of the soil. Eventually they will grow
  into a new plant.
► Rhizomes: Stems that run underground and
  sprout new plants.
► Suckers: Roots from the parent plant that
  produce new plants.
► Cuttings: When you cut the stem of a plant and
  put the stem into a good growing medium (soil,
  water) the cutting can produce new roots and
  continue to grow.
                   Grafting
         is another form of asexual
► Grafting
 reproduction.
   Grafting is when a cutting from one plant is
    inserted into the stem of a different plant.
   The cutting uses the other plants root systems
    to grow the cutting.
   This means that you could potentially have and
    apple tree that grows three different types of
    apples.
One example of how grafting is done

				
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