Plant reproduction

1. Lesson 15

2.  Plant reproduction is the process of producing y
oung plants. Plants reproduce in two different w
ays:
 Asexual Reproduction involves one parent pro
ducing genetically identical plants. Each plant is
a clone or exact copy of its parents.
 Sexual Reproduction involves two parents, a
male and a female, producing genetically differe
nt plants. The new plants are different from each
other and from the parents.

3.  There are several reasons why seed plants find
this form of reproduction advantageous. If the e
nvironment has been stable for many generatio
ns, variability may not be as essential to the sur
vival of the species.
 Asexual reproduction which is not as complex a
nd requires far less energy, would be preferabl
e.
 When colonizing a new area, finding a mate for
sexual reproduction may be difficult or impossibl
e.

4.  If the environment is particularly harsh, the m
ore delicate or susceptible organs or stages
of sexual reproduction may not be able to sur
vive.
 Many plants which inhabit such areas as des
erts or arctic tundra only reproduce asexually
.

5. Root Stem Leaf
The new dahlia plant
grows from a root
The new strawberry pl
ant grows from the ste
m or runner of a paren
t plant.
Roots and tiny new pl
ants form at the botto
m of a leaf cutting fro
m an African violet

6.  Nursery and greenhouses workers produce n
ew plants by Grafting. In grafting, the stem
of the one plant grows on the root system of
another plant. Experienced nursery workers
are knowledgeable about which plants can b
e grafted and different methods of grafting.
A
B

7.  Plant A grows excellent fruit
 Plant B grows strong roots
 Grafting combines desirable qualities of two
different plants. This allows us to combine tre
es that produce good fruit with trees that hav
e strong roots.

8.  Name four ways that plants reproduce asexually
 1 Roots
 2 stems
 3 Leaves
 4 Grafting

 What is the advantage of grafting plants?
 we can mix the good traits of plants


9.  Plants flowers contain its reproductive cells.
Many plants have both the male and female
sex organs on the same plant. In some case
s they will have male and female flowers on t
he same plant or they can have both the mal
e and female organs on the same flower.

10.  These plants are called Hermaphrodites
. Some plants such as poplars have separate
male plants and female plants. This type of s
exual reproduction is called? Sepa
rate Sexes

11.  Seeds are the product of sexual repro
duction in most plants. A seed is a complete r
eproductive package that contains an
Embryo , a food supply, and a seed coat
which protects it from Drying
Out .

12.  Two groups of seed-bearing plants are
Angiosperms and Gymnosperm
s .
 Flowering plants are called Angiosperms
. Seeds form inside the Flowers .
 The seeds are enclosed in a case called a
Pod or a shell .
 Some angiosperms include: Apples ,
Tomatoes , and sunflowers .

13.  Plants that do not produce flowers are called
gymnosperms .
 The seeds are produced inside Cones
.
 The seeds are not enclosed in a case but ha
ve Coat that protects them from
dehydration.
 Some gymnosperms include: Pine tr
ees and Fir trees

14.  Other plants such as ferns and
mosses reproduce sexually without bearing
seeds.

15.  The reproductive organs of an angiosperm ar
e found in the Flowers .
 The female reproductive organ is called the
Pistil . The pistil contains 4 parts.

16.  The stigma is the sticky part that c
aptures the pollen grains.
 The Style is the stalk that suppor
ts the stigma.
 The Ovary contains the ovules.
 The Ovules are sacs containing th
e female gametes.

17.  The male reproductive organ is called the
Stamen . The stamen contains 3 parts.
 The Anther is where the pollen is p
roduced and stored.
 The Pollen Grains are ca
ses containing the male gametes.
 The Filament is a stalk that supports t
he anther.

18. Pollen
Grains
Anther
Filament
Style
Ovary
Ovules
Stigma
Anther

19.  Pollination is the process of Pollen Grain
s from the anther reaching the stigma of th
e Pistil so that seeds can develop i
nside a flower.
 If the male and female gametes ( Egg and Sp
erm ) come from the same plant the process is call
ed Self pollination.
 If the gametes come from two different plants the pro
cess is called Cross Pollination .
 In order for fertilization to occur, the pollen grain grow
s and extension called a pollen Tube .


20.  A Zygote is formed when a sperm r
eaches an Egg . In some plants the o
vary surrounding the zygotes develops into t
he Fruit . The fruit helps to protect and
disperse the seeds.

21.  The transport of seeds away from the parent
plant is called Dispersal .
 Seeds can be eaten by Animals and fal
l far away as droppings.
 Seeds can also stick to Fur of mammal
s until rubbed off.
 Seeds can also be transported by the Wi
nd and by running water .

22.  The process by which a plant starts to grow i
s called Germination .

 Gymnosperms are also called Conifers
because their seeds are formed inside cones
.