Reproduction Topic 16
Reproduction means
producing new
living organisms . There are two types of reproduction : Sexual & Assexual Sexual Reproduction :
Two parents
·
with sex
organs
Assexual reproduction : Bacteria , Fungi & Plants Sex
organs make gametes (sex cells)
-
Involves 1 parent which provides all genetic information M F
All (clone)
genetically identical to Animals
-
off spring a re the parent Sperm cells egg cells
Little variation (any caused
by the environment :
availibility of nutrients & water) Plants pollen grains in Ovules
Must divide copied then chromosomes
by mitosis : first chromosomes &
-
,
cell
organelles are ,
are
pulled to opposite cell & the nucleus divides .
Finally the & cell membranes divide
sides of the
cytoplasm
During
·
sexual reproduction the ,
nuclei of the
gametes fuse together
at fertilisation . The fertilised egg (Zygote) divides to form an
embryo .
A gamete
zygote has a nucleus that contains 2 Sets of chromosomes -
one from each
Off spring aren't <Variation
·
genetically identical
Assexual Sexual
-
Fast -
Better able to survive & evolve
-
Little variation (cannot survive disease or
changes in the environment )
.
Compete with each other for resources
Reproduction in Plants :
Tuber formation :
Binary Fission :
Stem tubers swollen underground that parent Bacterial
grow from
stems the plant. cell divides into two cell wall. Their DNA loop copied
:
by making a new is for
·
The parent plant dies at the end of the leaving tubers to the winter
growing s e as on
,
survive over each new cell.
Spores :
Spores a re small & light they float through
,
the air .
When a spore lands on a damp surface it
, splits open , & a thread Chypha) grows
out It.
grows over the surface forming a mycelium (a dense network of threads)
Eventually ,
short hyphae grow upwards & produce sporangia (Spore cases) Inside . each
sporangium ,
hundreds of new
spores a re formed asexually by division of nuclei. Each nucleus gains a small quantity
of cytoplasm & a protective spore case . When ready ,
the sporangia break open & spores are dispersed .
Flower Structure :
Flowering plants reproduction by producing
·
carry out sexual flowers
Pollination :
process of transfer of pollen grains (made by male gametes ,
carried to female gametes)
Fertilisation fusion of : male & female gametes
Reproduction means
producing new
living organisms . There are two types of reproduction : Sexual & Assexual Sexual Reproduction :
Two parents
·
with sex
organs
Assexual reproduction : Bacteria , Fungi & Plants Sex
organs make gametes (sex cells)
-
Involves 1 parent which provides all genetic information M F
All (clone)
genetically identical to Animals
-
off spring a re the parent Sperm cells egg cells
Little variation (any caused
by the environment :
availibility of nutrients & water) Plants pollen grains in Ovules
Must divide copied then chromosomes
by mitosis : first chromosomes &
-
,
cell
organelles are ,
are
pulled to opposite cell & the nucleus divides .
Finally the & cell membranes divide
sides of the
cytoplasm
During
·
sexual reproduction the ,
nuclei of the
gametes fuse together
at fertilisation . The fertilised egg (Zygote) divides to form an
embryo .
A gamete
zygote has a nucleus that contains 2 Sets of chromosomes -
one from each
Off spring aren't <Variation
·
genetically identical
Assexual Sexual
-
Fast -
Better able to survive & evolve
-
Little variation (cannot survive disease or
changes in the environment )
.
Compete with each other for resources
Reproduction in Plants :
Tuber formation :
Binary Fission :
Stem tubers swollen underground that parent Bacterial
grow from
stems the plant. cell divides into two cell wall. Their DNA loop copied
:
by making a new is for
·
The parent plant dies at the end of the leaving tubers to the winter
growing s e as on
,
survive over each new cell.
Spores :
Spores a re small & light they float through
,
the air .
When a spore lands on a damp surface it
, splits open , & a thread Chypha) grows
out It.
grows over the surface forming a mycelium (a dense network of threads)
Eventually ,
short hyphae grow upwards & produce sporangia (Spore cases) Inside . each
sporangium ,
hundreds of new
spores a re formed asexually by division of nuclei. Each nucleus gains a small quantity
of cytoplasm & a protective spore case . When ready ,
the sporangia break open & spores are dispersed .
Flower Structure :
Flowering plants reproduction by producing
·
carry out sexual flowers
Pollination :
process of transfer of pollen grains (made by male gametes ,
carried to female gametes)
Fertilisation fusion of : male & female gametes
