Saturday, 10 December 2011

Tallest grass   - Bamboo 25m
Tallest cactus   Saguaro 18m
Biggest fern – Norfolk Island tree fern 20m
Biggest seed – Coco-de-mer palm 20kg
Biggest carnivorous plant – Nepenthes vines 10m
Longest leaf – Amazonian bamboo palm 20m
More than 80 per cent of all green plants have flowers. Flowers make seeds that develop into new plants. A plant that lives for only one year flowers at the end of its life. Most plants that live for many years flower every year.

ª These flowers come from the flax plant.Flax was the most important vegetable fibre in Europe before cotton.It is still used to make linen.

ª Bird of paradise flowers have a flat ‘landing platform’ for the birds that visit to feed on nectar.

ª Poppies die as soon as they have flowered.Each flower produces hundreds of seeds.

ª Thriff flowers grow at the tips of grass-like tufts on cliffs, rocks and salt marshes from April to October.

ª The yellow stigmas o the purple saffron crocus make saffron a valuable spice.

ª Apple blossoms are usually pink.They get their colour from anthocyanin pigments, which also turn leaves red in autumn.

ª Primrose flowers provide a vital source of nectar for early spring butterflies, such as the brimstone.Flowers grow from the base of the plant on long stalks.

ª Snowdrops flower early in the year, using energy stored in underground bulbs.

ª Passion flowers have in the middle of their flowers an unusual rig of flaments.
ª Daisies look like a single bloom but they actually consist of many small flowers.Those around the edge each have a single petal.

Plants have developed many different shapes of leaf in order to 
survive in different conditions.

ª     Tri-part leaf

ª     Heart-shaped

ª     Multiple

ª     Simple

ª     Spiky

Leaves are a plant’s powerhouse,using sunlight to make sugar,the plant’s fuel.Many leaves are broad and flat to catch the maximum amount of sunlight.Other shapes and styles may help to conserve water or help plants to cling to surfaces.

Ï Leaves come in many different shapes and sizes but there are two main types:needle-shaped leaves and broad leaves.
Ï Conifers,such as pine trees have needle-shaped leaves.
Ï Broad leaves are made by some trees and other woody plants in the flowering plant group.A broad leaf may be just a single leaf,such as an oak tree leaf or be made from a group of  leaflets, such as an ash tree leaf.
Ï Leaves are joined to the stem by a stalk called a petiole.
Ï The flat part of the leaf is called the blade.
Ï The leaf blade is like a sandwich with two layers of cells holding a thick filling of green cells.
Ï The green in the leaf comes from the chemical pigment chlorophyll.This traps the Sun’s energy, so that the plant can make sugar by photosynthesis.
Ï Chlorophyll is held in tiny bags in each cell called chloroplasts.
Ï To cut down water loss in dry places,leaves may be rolled-up,long and needle-like or covered in hairs or wax.
Ï Climbing plants such as peas have tips that coil into stalks called tendrils.The tendrils help the plant cling to vertical surfaces.
Ï Magnolia trees have the largest leaves and flowers of any tree outside the tropical forests.
Ï Bougainvillea does not produce colourful flowers but has colourful leaves instead.
Ï The leaves of the water hyacinth swell up with air to help the plant float.


1. Cycads were widespread by about 250 million years   
   ago.They were probably eaten by some dinosaurs.

2. The world’s smallest flower is the Wolffia angusta duckweed
of Australia.This is a floating water plant 0.6 mm long and  
0.33 mm wide.It can only be seen clearly when viewed under
a magnifying  glass.

3. One wild fig tree near Ohrigstad.Mpumalanga,South Africa  
is believed to have roots that reach down to a depth of 120m.

Ø Orchids living high on rainforest trees have special roots that absorb water from the air. Their thick, waxy leaves help to stop water escaping from the plant.

This farmer is harvesting seaweed. Many seaweeds are edible and in some places are considered delicacies. In addition, seaweed is used as an ingredient in many food product, including ice cream. Most of the water in ice cream freeze into very small ice crystals. Adding chemicals from seaweed slows down the growth of ice crystals in the ice cream and helps to keep the ice cream smooth. Seaweed is also used in cosmetics and as a fertilizer for farm craps.
v Tea is the dried leaves of the evergreen tea plant, which grows in the tropics, mostly at an altitude of between 1000 and 2000m. Tea plants can grow 9m tall, but they are pruned to 3m on tea plantations. Workers called tea pluckers pick leaves from mature tea plants by hand. The leaves are then taken to a nearby factory to be dried, crushed and treated.

Ë There are about 375,000 species of plant. The biggest plant family is the flowering plants or angiosperms, with over 250,000 species. Other important plant groups are mosses and liverworts (seen here),ferns and horsetails and conifers and cycads. Fungi used to be classed as plants,but as they cannot make their own food, they are now put in a class of their own, which includes about 100,000 species.
Ï What all plants share is the ability to capture the energy in sunlight. Plants, such as this sunflower,use this energy to fuel their own life processes, such as growth and reproduction. Animals, in turn, derive energy from plants by eating them.In this way,plants power all life on Earth.

Thursday, 1 December 2011


  The oldest living trees are bristlecone pines,some of which are more than 4000 years old.They have a long lifespan ,because they  grow  very slowly and live in cool,dry areas,such as Nevada,Utah and California in USA.

ª    The small, hardy rowan,also known as mountain ash ,grows up to 15m tall.It is most common throughout western and northern parts of the UK.

ª    Chocolate is made by grinding the kernels of cocoa beans to a paste called chocolate liquor.The liquor is hardened in moulds to make chocolate.

ª    The cycads and gingkos of today are the direct descendants of the first seed plants to appear on land.

ª    One orchid flower may produce more than 2 million tiny seeds.An orchid seed needs the help of a fungus to sprout  and obtain food.

Tuesday, 29 November 2011

ª    The survival of animals and plants are important to maintain the species.
ª    If the species of plants become extinct,the world may face a shortage of food.
ª    This is because plants are the main sources of  food to another animals.
ª    The animal is also a source of food to another animal.
ª    Some species of animals and plants may also be in danger of extinction because of some other factors such as deforestation or natural disaster.
Ë Plants also need to ensure the survival o their species.
Ë When the fruit of a plant is ripe, it either falls to the ground or splits open to release the seeds.
Ë If all the mature seeds falls straight down and germinate near the parent plaant will be crowded.
Ë Thus the young plants will have to compete or sunlight,water and mineral.
Ë To prevent this from happening,the seeds need to be adapted for dispersal.
Ë Dispersal means scattering or distributing the seeds to other places for germination.
Ë Different plants disperse their fruits and seeds in different ways.
Ë They are dispersed far and wide by agents such as:
·       Water
·       The wind
·       Animals
·       Explosive mechanism

1.Besides protecting themselves from danger and enemies,plants also need to  adapt  themselves to extreme weather conditions.
2.Some of these weather conditions include:
Ï  Hot and dry weather
Ï  Strong winds
Ï  Extremely cold weather

Ø Plants also have to adapt to their environment to survive.
Ø Plants have special characteristics to protect them from being destroyed by humans and animals.
Ø The following are some special characteristics of plants:-

 a thick and hard bark

 fine hairs

 production of latex

 production of poisonous substances

Sunday, 13 November 2011

1. Plants need to reproduce in order to continue to exist.
2.If plants do not reproduce,humans will not get food supply.Animals
  that feed on plants will also not survive and will become extinct.
3.Diffrent typaes of plants reproduce in different ways.
4.Ways of plant reproduce include reproducing:-
a) by seeds
b) through the leaves

c) through suckers

d) by spores

e) by the cuttings of stems

f) through underground stems

Saturday, 5 November 2011

1. Different parts of plants respond to different stimuli.
2. The movement of a plant involves the growth of certain parts of the plant.
3. Plants respond to the following stimuli:
a) gravity
b) water
c) sunlight
d) touch
4.When a part of a plant grows towards a stimulus it is said to show a positive  
5. However,when a part of the plant grows away from the stimulus it is said to
   show a negative response.

1. This is the growth of certain parts of a plant in response to gravity.
2. The roots o the plant grow downwards into the soil while the shoots and
     branches grow upwards.
3. The plant grows downwards into the soil to get water in order to make food.