Reproduction – Human & Plant
Types of Reproduction:
- Sexual Reproduction: Is the fusion of male and female gametes during
fertilization to produce non-identical offspring that inherit
characteristics from both parents
- Asexual Reproduction:
Asexual reproduction does not involve sex cells or fertilization
Only one parent is required, so 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 (clones)
Asexual Vs Sexual Reproduction:
Asexual Reproduction Sexual Reproduction
One parent is needed Two parents are needed
Cells divide by fission, budding or Cells divide by mitosis
fragmentation
Very little chance for genetic variation Genetic variation in offspring
No formation of gametes Formation of gametes (haploid)
Found in lower organisms (Bacteria) Found in higher, more complex organisms
(mammals)
Whole parent body, bud/fragment/single Unit is the gamete that results in fertilization
somatic cell (diploid zygote)
Creates a minimum of two offspring Creates a minimum of one offspring
Plants:
Pollination:
- Flowers are the reproductive organ of the plant
- They usually contain both male and female reproductive parts
- Plants produce pollen which contains a nucleus inside that is the male
gamete
- Unlike sperm, pollen is not capable of locomotion (moving from one
place to next)
, - This means plants need mechanisms in place to transfer pollen to the
female part of another plant
- This is known as pollination, and there are two main mechanisms by
which it occurs
Insect pollinated: Insects carry the pollen on them to the next
plant
Wind pollinated: Wind lifts pollen into the air to the next plant
- The structures of wind and insect pollinated plants are slightly different
as each is adapted for their specific function
Parts of the flower and their functions:
- Sepal: Protects unopened flower
- Petals: Brightly coloured for insect pollinated plants to attract insects
- Stamens: Male part of the flower, consisting of filament and anther
- Filament: Positions anther to release male sex cell (pollen grain)
- Anther: Produces and releases male sex cell
- Carpel: Female part of the flower, consisting of stigma, style, and ovary
- Stigma: Top of the female part of the flower which collects pollen
grains
- Style: Connects the stigma to the ovary
- Ovary: Produces the female sex cell (ovum)
- Ovule: Contains the female sex cells
- Nectary: Produces a sugary solution called nectar to attract insects
Adaptations of different types of plants:
Feature: Wind-Pollinated: Insect-Pollinated:
Pollen Grains Smooth and light so Sticky so they are able
they can be easily to be picked up and
carried by the wind in carried by insects from
large amounts, to make one plant to the next,
sure some reach other in moderate amounts
flowers
Anthers On the outside of the On the inside of the
flower, loose on long flower, stiff and
filaments so that pollen attached so that insects
can be released easily can brush past and
collect the pollen
Stigma On the outside of the On the inside of the
flower, feathered so it flower, sticky so pollen
Types of Reproduction:
- Sexual Reproduction: Is the fusion of male and female gametes during
fertilization to produce non-identical offspring that inherit
characteristics from both parents
- Asexual Reproduction:
Asexual reproduction does not involve sex cells or fertilization
Only one parent is required, so 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 (clones)
Asexual Vs Sexual Reproduction:
Asexual Reproduction Sexual Reproduction
One parent is needed Two parents are needed
Cells divide by fission, budding or Cells divide by mitosis
fragmentation
Very little chance for genetic variation Genetic variation in offspring
No formation of gametes Formation of gametes (haploid)
Found in lower organisms (Bacteria) Found in higher, more complex organisms
(mammals)
Whole parent body, bud/fragment/single Unit is the gamete that results in fertilization
somatic cell (diploid zygote)
Creates a minimum of two offspring Creates a minimum of one offspring
Plants:
Pollination:
- Flowers are the reproductive organ of the plant
- They usually contain both male and female reproductive parts
- Plants produce pollen which contains a nucleus inside that is the male
gamete
- Unlike sperm, pollen is not capable of locomotion (moving from one
place to next)
, - This means plants need mechanisms in place to transfer pollen to the
female part of another plant
- This is known as pollination, and there are two main mechanisms by
which it occurs
Insect pollinated: Insects carry the pollen on them to the next
plant
Wind pollinated: Wind lifts pollen into the air to the next plant
- The structures of wind and insect pollinated plants are slightly different
as each is adapted for their specific function
Parts of the flower and their functions:
- Sepal: Protects unopened flower
- Petals: Brightly coloured for insect pollinated plants to attract insects
- Stamens: Male part of the flower, consisting of filament and anther
- Filament: Positions anther to release male sex cell (pollen grain)
- Anther: Produces and releases male sex cell
- Carpel: Female part of the flower, consisting of stigma, style, and ovary
- Stigma: Top of the female part of the flower which collects pollen
grains
- Style: Connects the stigma to the ovary
- Ovary: Produces the female sex cell (ovum)
- Ovule: Contains the female sex cells
- Nectary: Produces a sugary solution called nectar to attract insects
Adaptations of different types of plants:
Feature: Wind-Pollinated: Insect-Pollinated:
Pollen Grains Smooth and light so Sticky so they are able
they can be easily to be picked up and
carried by the wind in carried by insects from
large amounts, to make one plant to the next,
sure some reach other in moderate amounts
flowers
Anthers On the outside of the On the inside of the
flower, loose on long flower, stiff and
filaments so that pollen attached so that insects
can be released easily can brush past and
collect the pollen
Stigma On the outside of the On the inside of the
flower, feathered so it flower, sticky so pollen
