topic 6: reproduction in plants
Plant reproduction is the production of new individuals or offspring in plants. Reproduction is either sexual or asexual. Sexual reproduction is the formation of offspring by the fusion of gametes (pollen and ova). Asexual reproduction is the formation of offspring without the fusion of gametes. Sexual reproduction results in offspring genetically different from the parents. Asexual offspring are genetically identical. New individuals may be packaged in a protective seed, which can be long lived and can disperse the offspring some distance from the parent. In flowering plants, the seed is contained inside a fruit, which protects the seed and helps in their dispersal.
Explain the differences between sexual and asexual reproduction
Plants have two ways of reproduction; sexual and asexual. .
Sexual reproduction produces offspring by the fusion of gametes. This results in genetically different offspring. Asexual reproduction produces new individuals without the fusion of gametes. These are genetically identical to their parents.
Plants have two main types of asexual reproduction. Vegetative reproduction involves a vegetative piece of the original plant. Apomixis occurs in many plant species and also in some non-plant organisms.
Asexual reproduction in plants can occur in a variety of forms, including budding, vegetative propagation, and fragmentation
Sexual reproduction produces offspring by the fusion of gametes. This results in genetically different offspring. Asexual reproduction produces new individuals without the fusion of gametes. These are genetically identical to their parents.
Plants have two main types of asexual reproduction. Vegetative reproduction involves a vegetative piece of the original plant. Apomixis occurs in many plant species and also in some non-plant organisms.
Asexual reproduction in plants can occur in a variety of forms, including budding, vegetative propagation, and fragmentation
Types of asexual plant reproduction
Describe the structures of the flowering plant
Petal - Colourful part of the flower. Attracts insects in insect-pollinated plants
Anther - Male part of the plant. Makes pollen.
Filament - Joins the anther to the rest of the flower.
Stigma - Female part of the plant. Receives pollen.
Ovary - Contains the ovules
Ovule - Eggs – female gametes
Pollen - Male gamete
Nectary - Makes nectar to attract insects in insect-pollinated plants
Sepal - Protects the flower when it is in bud
Anther - Male part of the plant. Makes pollen.
Filament - Joins the anther to the rest of the flower.
Stigma - Female part of the plant. Receives pollen.
Ovary - Contains the ovules
Ovule - Eggs – female gametes
Pollen - Male gamete
Nectary - Makes nectar to attract insects in insect-pollinated plants
Sepal - Protects the flower when it is in bud
image from internationalgcsebiology.wikispaces.com
Explain that fertilisation involves the fusion of a male and female gamete to produce a zygote that undergoes cell division and develops into an embryo
Gametes are sex cells of the plant; the male one being pollen; the female one being an ova. When they join together it is know as fertilisation. At this point the fused gametes become a zygote. The zygote divides repeatedly and becomes an embryo.
Describe the structures of an insect-pollinated and a wind-pollinated flower and explain how each is adapted
for pollination
for pollination
Describe how fruits and seeds may be adapted for dispersal
A seed (mature ovule) is a miniature plant with a protective cover in a suspended state of development. Most seeds contain a built-in food supply called endosperm.
The outer covering of a seed is called the seed coat. Seed coats help protect the embryo from injury and also from drying out. Seed coats can be thin and soft or thick and hard. Endosperm, a temporary food supply, is packed around the embryo in the form of special leaves called cotyledons. These generally are the first parts visible when the seed germinates.
Plants are classified based upon the number of cotyledons in the seed. Plants such as grasses can be monocots, containing one cotyledon. Dicots are plants that have two cotyledons.
The outer covering of a seed is called the seed coat. Seed coats help protect the embryo from injury and also from drying out. Seed coats can be thin and soft or thick and hard. Endosperm, a temporary food supply, is packed around the embryo in the form of special leaves called cotyledons. These generally are the first parts visible when the seed germinates.
Plants are classified based upon the number of cotyledons in the seed. Plants such as grasses can be monocots, containing one cotyledon. Dicots are plants that have two cotyledons.
image from singlemotherof4plantbabies.blogspot.com
Describe the structural changes that accompany germination of the seed
Seeds remain dormant or inactive until conditions are right for germination. All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also. Some germinate better in full light while others require darkness to germinate.
When a seed is exposed to the proper conditions, water and oxygen are taken in through the seed coat. The embryo start to enlarge. Then the seed coat breaks open and the radicle emerges, followed by the plumule that contains the leaves and stem
When a seed is exposed to the proper conditions, water and oxygen are taken in through the seed coat. The embryo start to enlarge. Then the seed coat breaks open and the radicle emerges, followed by the plumule that contains the leaves and stem
Key Terms
|
sexual reproduction asexual reproduction
cuttings disperse stigma style ova ovary |
fruit
anthers stamen ovules ovaries pollen tube self-pollination cross-pollination |
wind pollinated carpel
filaments sepals petal radicle plumule germinate |
testa
disperse cotyledon dormant dicotyledonous monocotyledonous micropile insect pollinated |
bulb
stolen runners rhizome hypocotyle fertilisation pollen tube |
Classroom Material
Reproduction in Plants (ppt)
Reproduction in Plants (study guide)
Flower dissection practical
Flower Structure and Reproduction in Plants worksheet
Reproduction in Plants (ppt)
Reproduction in Plants (study guide)
Flower dissection practical
Flower Structure and Reproduction in Plants worksheet
Part 1 Plant Reproduction
Part 2 Parts of the Flower
Part 3 Pollination and Fertilization
Part 4 Germination
Useful Links
Asexual reproduction from BBC Bitesize
Sexual reproduction from BBC Bitesize
A nice review on Plant Reproduction from Biology4Kids
Shmoop Biology Plant Reproduction
Pollination vs Fertilisation Buzzle
A review of plant reproduction from Think Quest
Biology 4 Kids
Flowering Plant Reproduction animation from W.W. Norton
Excellent resource on Pollinators from USDA
Asexual reproduction from BBC Bitesize
Sexual reproduction from BBC Bitesize
A nice review on Plant Reproduction from Biology4Kids
Shmoop Biology Plant Reproduction
Pollination vs Fertilisation Buzzle
A review of plant reproduction from Think Quest
Biology 4 Kids
Flowering Plant Reproduction animation from W.W. Norton
Excellent resource on Pollinators from USDA
Video Clips
Plant Asexual Reproduction
Sexual reproduction in flowering plants
Another great video clip by Hank Green on Plant Reproduction. Don't pay too much attention to the ferns and spores. It is interesting, but not needed.
Bill Nye talks about flowers
Methods of Pollination
Emerging Explorer Dino Martins says that from long-tongued bees to hawk moths, pollinators are the hidden workers that keep the planet running.
This video was shown at the TED conference in 2011, with scenes from "Wings of Life", a film about the threat to essential pollinators that produce over a third of the food we eat. The seductive love dance between flowers and pollinators sustains the fabric of life and is the mystical keystone event where the animal and plant worlds intersect that make the world go round.
Plants use many ingenious methods to distribute their seeds. Here we see some of the ways this is done, from a high pressure jet to using rain power. This video is taken from BBC's The Private Life of Plants documentary series.
Discovery Education Plant gernimation
Amazing timelaspe video on seed germination
