Thursday, January 6, 2011

Task 2 - Plantae

Non-flowering Plants

Non-flowering plants do not have flowers or fruits, like mosses and ferns, which reproduce from spores. They are green and can make their own food.

Non-flowering plants do not produce seeds and usually reproduce from spores. Spores are found in spore bags located on the underside of mature leaves or at the end of stalks.

Spores are tiny and can only be examined under a microscope. They are generally dispersed by wind as they are light. Like seeds, spores will germinate and grow into young plants when the conditions are favourable.

Other than reproducing by spores, plants can reproduce by plant parts too, such as:

-Underground stem
Such buds have buds and leaves or leaf scars. It’s leaves are not green, and they can be scaly or fleshly. Some common examples are potato, ginger, and onion.

Suckers are shoots that grows from a small bud. These buds are found at the base of the stem of the parent plant. Some common examples are banana plants, palm, pineapple and heliconia.

The plant’s leaves are think and fleshy. Buds are found on the edge of a mature leaf. When the leaf falls to the ground, these buds grow and develop into new plants. Some common examples are bryophyllum, the african violet and the begonia violet.

Done By: Ethan Soh

AND a Science Revision Guide Book (Science psle revision guide. (2007). Singapore: Marshall Cavendish Education.)

Flowering Plants

Flowering plants are also known as Angiosperms or Magnoliophyta, and are the most diverse group of land plants. Angiosperms are seed-producing plants like gymnosperms(plants that reproduce by seeds such as acorns, cones and pines). They have many key derived characteristics, which are:

The flowers, which are the reproductive organs of flowering plants, are the most remarkable feature distinguishing them from the other seed plants. Flowers aid angiosperms by enabling a wider range of adaptability and broadening the ecological niches open to them. This has allowed flowering plants to largely dominate terrestrial ecosystems.

-Stamens with two pairs of pollen sacs
Stamens are much lighter than the corresponding organs of gymnosperms and have contributed to the diversification of angiosperms through time with adaptations to specialized pollination syndromes, such as particular pollinators. Stamens have also become modified through time to prevent self-fertilization, which has permitted further diversification, allowing angiosperms eventually to fill more niches.

(Further Information)
Endosperm formation generally begins after fertilization and before the first division of the zygote. Endosperm is a highly nutritive tissue that can provide food for the developing embryo and sometimes for the seedling when it first appears.

Despite their diversity, angiosperms are clearly united by a suite of synapomorphies(i.e., shared, dervied features) including
Ovules that are enclosed within a carpel, that is, a structure that is made up of an ovary, which encloses the ovules and the stigma, a structure where pollen germination takes place,
Double fertilization, which leads to the formation of an endosperm(a nutritive tissue within the seed that feeds the developing plant embryo),
Stamen with two pairs of pollen sacs,
Features of the gametophyte structure and development and 
Phloem tissue composed of sieve tubes and companion cells.

Done By: Celine Chee


3 exceptions of plants:

They have tiny needle like leaves which help reduces water loss in their habitat, the desert.
The cactus also have a thick stem to store water.
Did you know that most people who goes on desert expeditions, cut cactus to drink the water in it. Cactuses are stored with quite a huge amount of water in them.

Antarctic Plants:
Lichens,Mosses,Algae and liverworts.
Of all the plants, lichens are best adapted to survive in the harsh polar climate.
The peculiarity of lichens is that they are not one homogeneous organism but a symbiosis of two different partners, a fungus and an alga. The fungus part supplies the plant with water and nutritious salt, meanwhile the alga part organic substance, like carbohydrate produce. With this ideal "job-sharing", lichens can survive the hardest conditions.

The grow in swamp areas thus the soil in usually denser, making water harder to flow through to reach the roots.
Thus the roots stick out of the soil to get more water and air.
They have the ability to live in saltwater by strainging freshwater from the saltwater through their roots

Done By: Clarabelle Ang



  1. I have learnt that the flowers are the reproductive organs of flowering plants.
    I have discovered that the growth rate of plants is extremely variable. Some mosses grow less than 0.001 millimeters per hour (mm/h), while most trees grow 0.025-0.250 mm/h. Some climbing species which do not need to produce thick supportive tissue, may grow up to 12.5 mm/h.

  2. 1 thing i learned is that the mangrove trees have roots sticking out of the ground to get more water and air.

    1 thing i discovered is that the cactuses have spongy tissue in its stems to hold the water in and they force all the water down to the roots.

  3. I have learnt that plants can also use their leaves to reproduce. I also learned that lichens are the best to survive in harsh polar climates. Mangroves can strain freshwater from seawater.

    I have discovered that seaweeds are actually under the group algae. They are classified among green, red and brown algae. There are about 3500 species of plant that are defined as seed plants. Fossils of green algae from the Cambrian are the earliest know fossils that can be assigned to the kingdom plantae.

  4. I have learnt that...Lichens are capable to survive in extreme climates. They are actually a symbiosis of two organisms, the Algae and Fungi. The Fungi part supplies the algae with water and nutrients, while the algae produces carbohydrates. They will sustain each other and so Lichens can survive.

    I discovered that...there are other types of non-flowering plants that are called conifers. They reproduce by pine cones, and they tend to grow in cold areas. They can survive through cold weather, such as winter.

  5. I have learnt that of all the plants, lichens are best adapted to survive in the harsh polar climate.

    I have discovered that peculiarity of lichens is not one homogeneous organism but a symbiosis of a fungus and an alga. The fungus part supplies the plant with water and nutritious salt, meanwhile the alga part organic substance, like carbohydrate produce.

  6. I have learnt that different non-flowering plants have many different ways of reproducing, whereas the reproductive organs of flowering plants are always the flowers.

    I have discovered that plants started to vary and more species of plants started to appear somewhere in the mid-Cretaceous period, approximately 100 million years ago. They started to take over places that were previously occupied by ferns and conifers.

  7. I have learnt that:
    different plants reproduce differently and that the are 5 groups of plants, of which includes mosses and flowering plants.

    I have discovered that:
    The first land plant on Earth was thought to be found 400 - 700 million years ago. There are common misconceptions regarding the classification of different species of plants. E.g. Bamboo is a grass and not a tree.

  8. I have learned that the needles on a cactus are actually leaves which helps the cactus to reduce water loss in their desert habitat.

    I have discovered that banana plants can reproduce in 2 different ways,sexually through flowers or asexually through underground stems.

  9. I have learnt that there are some organisms which will help each other to grow, like the fungus and alga.

    I have discovered that there are 350,000 species of plants.

  10. I have learnt Non flowering plants can reproduce using Underground stem,Sucker and Leaf other than spores.

    I discovered that The genotype of a plant affects its growth. For example, selected varieties of wheat grow rapidly, maturing within 110 days, whereas others, in the same environmental conditions, grow more slowly and mature within 155 days.

  11. i have learnt that the needles on a cactus are actually leaves.

    i have discovered that the Echinopsis oxygona cactus' flowers bloom in the evening and dies in the morning

  12. I've learnt that..
    Cactus: Cactuses are stored with quite a huge amount of water in them.
    Flowering plants: The flowers, which are the reproductive organs of flowering plants
    Non-flowering Plants: Non-flowering plants do not produce seeds and usually reproduce from spores.

    I've dicovered that..
    Most seedless vascular plants are homsporous, but some (e.g., the lycophyte Selaginella) are heterosperous
    Homosporous- Sporophyte-> Single type of spore-> Bisexual gametophyte (with both kinds of gametangia)-> Eggs & sperm
    ->Microspore->Male gametophyte->Sperm
    Heterosporous- Sporophyte
    ->Megaspore->Female gametophyte->Eggs

  13. I've learnt:

    the key characteristics of the 3 groups of plants.

    Ive discovered more about some other groups of plants:cactus,mangrove

    What's the difference between a moss and a fern?
    Where's the other 2 groups of plants(I tot there was 5 groups)?

    **Thanks Celine for the Definition of the words**

  14. Mangrove plants have roots sticking out of the water to get more air.

    I learnt that cactus has spongy tissue to hold water.