Chloë van Beukering Life Sciences Notes 2020
Reproduction in Flowering Plants
- Sexual reproduction: mode of reproduction by bringing together genetic material of two
parents
- Asexual reproduction: mode of reproduction of a new generation by one parent
- Binary ssion: a single cell that produces a new identical cell e.g. amoeba, bacterium
- Budding: a new cell develops as an outgrowth or bud e.g. yeast
- Vegetative propagation: one plant grows from a fragment of a parent plant
- Grafting: plant that has a twig or bug attached to another to growth together e.g. roses
- Cuttings: stem cut from a parent plant and re-planted e.g. plum
- Tissue culture: growth of a new plant in a cultured medium (agar)
Asexual Reproduction
- Asexual reproduction needs only one parent, unlike sexual reproduction, which needs two
parents
- Since there is only one parent, there is no fusion of gametes and no mixing of genetic
information
- As a result, the offspring are genetically identical to the parent and to each other
- They are clones
- Asexual reproduction in plants can take a number of forms
- Many plants develop underground food storage organs that later develop into the following
year’s plants
- e.g. potato plants and daffodil plants
Advantages of asexual reproduction:
1. Large number of offspring are produced rapidly and simply, in favourable conditions
2. Energy expenditure is low as no gametes are produced
3. Offspring will adapt easily to same environmental conditions as the parent, as they are
identical
Disadvantages of asexual reproduction:
1. No recombination of genes
2. An asexual population tends to be genetically static
3. Mutant alleles more likely to get passed on
4. Overcrowding may occur with resources becoming limited
General types of asexual reproduction:
1. Binary Fission
- Most common form of reproduction in prokaryotes and occurs in some single-celled eukaryotes
- After replicating its genetic material, the cell divides into two equal sized daughter cells
- The daughter cells are genetically identical (unless a mutation occurred during replication) to
each other and the parent cell
- e.g. amoeba and bacterium
2. Budding
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fi
, Chloë van Beukering Life Sciences Notes 2020
- A form of asexual reproduction in which a new organism develops
from an outgrowth or bud on another one
- The small bulb-like a projection coming out from the yeast cell is
called a bud
- The new organism remains attached as it grows, separating from the
parent organism when it is mature
- Since the reproduction is asexual, the newly created organism is a
clone and is genetically identical to the parent organism
Asexual reproduction in plants:
Vegetative propagation
- A form of asexual reproduction of a plant
- Only one plant is involved and the offspring is the result of one parent
- The new plant is genetically identical to the parent
- New plants grow from parts of the parent plant
- Involves artificial means and natural means by which plants reproduce
- Propagation is faster than from seed because there’s no gamete formation, pollination etc.
- The new plants are of a consistent quality, as they will all have the same genetic makeup
- Larger quantities of plants can be produced cheaply, easily and quickly
- Plants can be produced naturally using runners, e.g. grass
- Grafting can produce disease resistant plants, and plants that grow more quickly to maturity
and thus to fruit production
Natural Forms of Vegetative Propagation
- The production of plants from vegetative parts of the plants like stems, roots, leaves etc.
1. Runners / stolons - Some plants produce long side shoots that
develop roots, eventually forming a new
plant
- e.g. strawberry, spider plant
2. Leaves Some plants, such as the Leaf of Life, have
young plants on their leaves which will grow
into new plants if planted or when they fall off
3. Rhizomes - These are underground theme that can
develop into new plants
- They grow sideways in the soil and have a
shoot with leaves
- e.g. ginger
4. Suckers - Banana is a good example of a plant that
reproduces in this manner
- A new stem grows from the base of an old
one, forming a new plant
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Reproduction in Flowering Plants
- Sexual reproduction: mode of reproduction by bringing together genetic material of two
parents
- Asexual reproduction: mode of reproduction of a new generation by one parent
- Binary ssion: a single cell that produces a new identical cell e.g. amoeba, bacterium
- Budding: a new cell develops as an outgrowth or bud e.g. yeast
- Vegetative propagation: one plant grows from a fragment of a parent plant
- Grafting: plant that has a twig or bug attached to another to growth together e.g. roses
- Cuttings: stem cut from a parent plant and re-planted e.g. plum
- Tissue culture: growth of a new plant in a cultured medium (agar)
Asexual Reproduction
- Asexual reproduction needs only one parent, unlike sexual reproduction, which needs two
parents
- Since there is only one parent, there is no fusion of gametes and no mixing of genetic
information
- As a result, the offspring are genetically identical to the parent and to each other
- They are clones
- Asexual reproduction in plants can take a number of forms
- Many plants develop underground food storage organs that later develop into the following
year’s plants
- e.g. potato plants and daffodil plants
Advantages of asexual reproduction:
1. Large number of offspring are produced rapidly and simply, in favourable conditions
2. Energy expenditure is low as no gametes are produced
3. Offspring will adapt easily to same environmental conditions as the parent, as they are
identical
Disadvantages of asexual reproduction:
1. No recombination of genes
2. An asexual population tends to be genetically static
3. Mutant alleles more likely to get passed on
4. Overcrowding may occur with resources becoming limited
General types of asexual reproduction:
1. Binary Fission
- Most common form of reproduction in prokaryotes and occurs in some single-celled eukaryotes
- After replicating its genetic material, the cell divides into two equal sized daughter cells
- The daughter cells are genetically identical (unless a mutation occurred during replication) to
each other and the parent cell
- e.g. amoeba and bacterium
2. Budding
1 of 9
fi
, Chloë van Beukering Life Sciences Notes 2020
- A form of asexual reproduction in which a new organism develops
from an outgrowth or bud on another one
- The small bulb-like a projection coming out from the yeast cell is
called a bud
- The new organism remains attached as it grows, separating from the
parent organism when it is mature
- Since the reproduction is asexual, the newly created organism is a
clone and is genetically identical to the parent organism
Asexual reproduction in plants:
Vegetative propagation
- A form of asexual reproduction of a plant
- Only one plant is involved and the offspring is the result of one parent
- The new plant is genetically identical to the parent
- New plants grow from parts of the parent plant
- Involves artificial means and natural means by which plants reproduce
- Propagation is faster than from seed because there’s no gamete formation, pollination etc.
- The new plants are of a consistent quality, as they will all have the same genetic makeup
- Larger quantities of plants can be produced cheaply, easily and quickly
- Plants can be produced naturally using runners, e.g. grass
- Grafting can produce disease resistant plants, and plants that grow more quickly to maturity
and thus to fruit production
Natural Forms of Vegetative Propagation
- The production of plants from vegetative parts of the plants like stems, roots, leaves etc.
1. Runners / stolons - Some plants produce long side shoots that
develop roots, eventually forming a new
plant
- e.g. strawberry, spider plant
2. Leaves Some plants, such as the Leaf of Life, have
young plants on their leaves which will grow
into new plants if planted or when they fall off
3. Rhizomes - These are underground theme that can
develop into new plants
- They grow sideways in the soil and have a
shoot with leaves
- e.g. ginger
4. Suckers - Banana is a good example of a plant that
reproduces in this manner
- A new stem grows from the base of an old
one, forming a new plant
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