What characteristics unify angiosperms?
Angiosperms are flowering plants, that only reproduce sexually through pollination taking place in flowers. Seeds of angiosperms are contained within a protective barrier called a fruit.
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| This is a picture of a angiosperm flower being pollinated by a bee. |
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| Four pictures of flowering angiosperms. |
Below is a diagram of the alternation of generation life cyle of an angiosperm.
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The angiosperm life cycle starts with the development of the diploid flower on the sporophyte plant. After pollination, the pollen grain develops on the stigma, and a pollen tube grows. This process has double fertilization which is unique to flowering plants. The mature ovary forms a fruit around the seed.
Monocot or Dicot?
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| Irises are monocots |
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Pansies are Dicots
You can tell the difference between dicots and monocots by looking at the number of petals the flower has.
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Monocot flowers tend to have a number of parts that is divisible by three, or six.
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| Daffodils are monocots, they have 6 petals |
Dicot flowers on the other hand, tend to have parts in multiples of four or five.
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| Buttercups are dicots, they have 5 petals |
Another way to differentiate between monocots and dicots is to look at the leaf patterns.
In monocots, there are usually a number of major leaf veins which run parallel the length of the leaf.
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| Monocot leaf |
In dicots, there are usually many smaller veins which sprout off of the major ones.
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| Dicot leaf |
Another way to tell is looking at the arrangement of the vascular bundles located within the stem. If the stem vascular bundles are scattered, then the plant is a monocot. If the stem vascular bundles form a ring, then the plant is a dicot.
How do the angiosperm features aid in survival in a land environment?
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- A major advantage of flowers is
that they have allowed angiosperms to use other organisms to move their pollen
about.
- Fruit protects and encloses the seeds and aids in their dispersal.
- Roots are used by the angiosperms to absorb nutrients from the soil.
- Leaves are the major site of food production for the plant
- Vascular tissues provide channels for the transport of water and nutrients.
The stem Protects the vascular system of the plant from the dangers on land
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from wikipedia:
ReplyDelete"A cotyledon (/ˌkɒtɪˈliːdən/; "seed leaf" from Latin cotyledon,[1] from Greek: κοτυληδών kotylēdōn, gen.: κοτυληδόνος kotylēdonos, from κοτύλη kotýlē "cup, bowl") is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed."[2] The number of cotyledons present is one characteristic used by botanists to classify the flowering plants (angiosperms). Species with one cotyledon are called monocotyledonous ("monocots"). Plants with two embryonic leaves are termed dicotyledonous ("dicots")."