LIFE SCIENCES GRADE 11 CAPS STRUCTURED CLEAR PRACTICAL

LIFE SCIENCES GRADE 11 CAPS STRUCTURED, CLEAR, PRACTICAL - HELPING TEACHERS UNLOCK THE POWER OF NCS KNOWLEDGE AREA: Diversity, change and continuity TOPIC 1: Biodiversity of Plants and Reproduction Seeds

SUMMARY OF PRESENTATION: Bird pollinated Flowers Significance of seeds Advantages of the Seed for the Plant Seeds as sources of food The Need for Seed and DNA banks

BIRD POLLINATED FLOWERS Flowers that are pollinated by birds have the following adaptations: 1. Long tube shaped flowers. 2. The flowers are bright red and yellow. 3. They have no odour � When the bird obtains nectar, it sticks its thin long beak into the flower. � The pollen grains sticks to their beak. �

BIRD POLLINATED FLOWERS � � When they visit the next flower some of this pollen is transferred to the stigma of the next flower. Some examples of flowers that are pollinated by birds are Aloes and bird of paradise. Strelitzia- (Bird of paradise)

SIGNIFICANCE OF SEEDS � All seed bearing plants belong to the phylum Spermatophyta. plants in this phylum maybe divided into 2 groups. � These 2 groups are: 1. Gymnosperms 2. Angiosperm � The gymnosperms are plants who bear seeds but their seeds are naked, they do not occur within fruit. � The angiosperms also bear seeds but their seeds occur within fruits. � The

SIGNIFICANCE OF SEEDS A seed has the following structure: � It is surrounded on the outside by a seed coat or testa. � The testa protects the contents of the seed from drying out. � The testa encloses the cotyledon. � The cotyledon is a source of stored food for the embryo. � The embryo is found within the seed. The embryo is made up of the radicle, plumule and axis.

ADVANTAGE OF THE SEEDS FOR PLANTS: � The seed has 4 advantages for the plant. � These advantages are: 1. Seeds have a dispersal mechanism, for example the seed of the pine plant has a parachute that enables them to be carried by the wind. These dispersal mechanisms allow the seeds to be widely dispersed. This reduces competition amongst the plants.

ADVANTAGE OF THE SEEDS FOR PLANTS: 2. The testa and cotyledons helps the embryo survive unfavourable conditions because the testa prevents the embryo from drying out and the cotyledons provide the embryo with food, thus 3. enabling the embryo to remain dominant until favourable conditions return. The testa and cotyledon is able to provide the 4. embryo with in the early stages of development. The cotyledon is able to provide the seedling with protection growth energy for until it is able to produce its own food, when its leaves develop.

SEEDS AS A SOURCE OF FOOD: � Some seeds provide humans with food. For example maize, wheat, rice and beans. Many of these seeds form the staple part of the diet. maize wheat rice

SEEDS AS A SOURCE OF FOOD: � Seeds can be used to make beverages such as cocoa and coffee. � Seeds can also be used as spices, for example black pepper, mustard and cumin. Coffee Beans Cocoa

SEEDS AS A SOURCE OF FOOD: � Other parts of the seed bearing plants can provide us with food. Such as potatoes and sweet potatoes. � About 80% of all food eaten by humans come from 6 seed bearing plants, they are rice, maize, wheat, potatoes, sweet potatoes and cassava. Cassava

THE PRESERVATION OF OUR ENDEMIC SPECIES USING SEED &DNA BANKS. � There are 3 areas in South Africa that are biodiversity hotspots. � These are the Cape Floristic region, the Succulent Karoo and Maputoland-Pondoland-Albany hotspot of the Eastern Cape. � These areas have many endemic plant species, for example about 80% of the plants found in the Cape Floristic region are endemic, 40% of the plants in the Succulent Karoo are endemic, it also has 3 endemic mammal species, 8 endemic reptile species and 1 endemic amphibian species.

THE PRESERVATION OF OUR ENDEMIC SPECIES USING SEED &DNA BANKS. � Remember endemic means that species only occurs in that area or region and no where else in the world. � Therefore it is extremely important to ensure that these species are protected. �Indigenous � Remember species must also be conserved. it is possible that these species may have uses that have not yet been discovered. � For example they could be a source of food or even a cure for an illness that has not yet been discovered.

THE PRESERVATION OF OUR ENDEMIC SPECIES USING SEED &DNA BANKS. � Therefore seed banks and DNA banks have been established. � It is hoped that these banks will helps us preserve all these species. � In 2001 an international programme was started in the Royal Botanic Gardens in Kew, England. � This programme is called the Millennium Seed Bank Project. � It is a 9 year plant conversation programme. � This programme aims to collect and conserve 10% of the world’s seed bearing flora by 2010.

THE PRESERVATION OF OUR ENDEMIC SPECIES USING SEED & DNA BANKS. � It hopes to achieve this by developing partnerships with other countries. � It hopes encourage these countries to develop their own seed banks. � The South African partner of this programme is the South African National Biodiversity Institute (SANBI). hopes to collect about 10% of South Africa’s indigenous flowering plants. � Especially those species that are endangered or endemic or threatened with extinction. � SANBI

THE PRESERVATION OF OUR ENDEMIC SPECIES USING SEED & DNA BANKS. �A DNA bank was also established in the Kirstenbosch Botanical Gardens in the Western Cape. � A DNA bank is a freezer set at -80˚C. � It stores extracts of DNA at this temperature. � Its objective is to store the nuclear, mitochondrial and plastid DNA extraction of all the plant species found in South Africa. � There are 22 000 of these species.

TERMINOLOGY: � Spermatophyta: the phylum made up of seed bearing plants. � Endemic: means that the species only occurs in that area or region and no where else in the world � Mitochondrial DNA: is the DNA found in the mitochondria. � Plastid DNA: is the DNA found in the chloroplast. � Nuclear DNA: is the DNA found in the nucleus. � Indigenous species: these are species that occur naturally in the area.

QUESTION 1 The radicle grows into the… A. First root B. Stem C. Leaf D. A and B

QUESTION 2 The part of the seed that protect the embryo in its early stages are… A. Testa and cotyledon B. Testa and seed coat C. Cotyledon and plumule D. Testa and plumule

QUESTION 3 The seedling obtains its food… A. Through photosynthesis even when it has just emerged from the seed. B. From the cotyledon until it is able to produce its own food. C. From the plumule. D. From the axis.

QUESTION 4 The phylum that produces seed-bearing plants is called… A. Bryophyta B. Pteridophyta C. Gymnosperm D. Spermatophyta

QUESTION 5 The phylum that produces naked seeds is called… A. Bryophyta B. Pteridophyta C. Gymnosperm D. Angiosperm

QUESTION 6 The phylum that bears seeds within fruit is… A. Bryophyta B. Pteridophyta C. Gymnosperm D. Angiosperm

SOLUTION: 1. 2. 3. 4. 5. 6. A A B D C D