Reproduction in plants, biology, IG
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Transcript of Reproduction in plants, biology, IG
Made by: Fatima Al-ZahraaGrade: 7ASubject: BiologyTo: Miss Ashraf
REPRODUCTION IN PLANTS
Reproduction??• Reproduction is the process by which animals and plants produce new individuals.
Types of Reproduction
Reproduction
Sexual Reproduction
Asexual Reproduction
Artificial Reproduction
Reproduction in Plants
Plants
Flowering Plants
Non-Flowering
Plants
Flowering Plants• Flowering plants are plants that can reproduce more than one way like sexual and asexual.
E.g. Tulips
Nonflowering Plants• Nonflowering plants are plants that reproduce using spores/ specialized gametes.
E.g. Ferns
Types of Flowers
i. Complete Flower
ii. Incomplete Flower
iii. Bisexual Flower
iv. Unisexual Flower
v. Regular Flower
vi. Irregular Flower
Complete Flowers
•Flowers which have all the four parts of the flower ( petals, sepals, carpel, stamen) are known as complete flowers.
E.g. Roses
Incomplete Flowers
• Flowers that lack one or more parts of a flower is known as an incomplete flower.
E.g. Black walnut
Bisexual Flowers
• Flowers that have both sexes ( stamen and carpel) are known as bisexual flowers.
E.g. Lily
Unisexual Flowers
• Flowers which have only one sex ( carpel or stamen) are known as unisexual flower.
E.g. Watermelon
Regular Flowers
• Flowers that are radially symmetrical are known as regular flowers.
E.g. Crocus
Irregular Flowers
• Flowers that are bilaterally symmetrical are known as irregular flowers.
E.g. Pea
Parts of the Flower
•Four parts which are•Sepals/ calyx•Petals/ corolla•Carpel•Stamen
Sepals/ CalyxFunction?• The sepals protect the flower during bud condition.
Sepals
Petals•Petals are large and bright coloured.
Function?• Its function is to attract insects for pollination.
Very attractive
Stamens•Stamen is the male reproductive organ as it contains the male gametes.Parts of Stamen• Anther It contains pollen which contains male gamete• Filament It supports the anther
Function?•Stores the male gamete and is the male reproductive organ.
Stamen
Carpel• It is the female reproductive organ as it contains the ovum.
Parts of the carpelStigma: It is the receiving surface of pollenStyle: It connects the stigma with the ovaryOvary: It contains and protects ovules.
Function?It contains the ovum and is the female reproductive organ in
the plant.
Carpel
Receptacle•Function?• It is where the flower starts developing.
Pollination• Reproduction in plants can’t occur without pollination. Pollination is the transfer of pollen from the anther to the stigma of a flower.
Pollination
Self pollinati
on
Cross pollinati
on
Self PollinationSelf pollination occurs when the pollen is transferred from the anther of a flower to the stigma of the same flower or another flower of the same plant.
Cross Pollination
• Cross pollination occurs when the pollen is transferred from the anther to a stigma of another flower of another plant of the same species.
Ways of Pollination
Wind Pollination
Insect Pollination
Adaptations of Wind-pollinated flowers
•Petals are dull or absent
•No scent or nectar•Anthers dangling outside flower
•Stigma is feathery
•Pollen is small and light weight
Adaptations of Insect-pollinated flowers
• Petals are large and colourful
• Scent and sweet nectar is present• Filaments are short so stamens are inside flower
• Stigma is smooth
• Pollen is large, spiky and sticky
Fertilisation• After pollination takes place fertilisation occurs.•When the pollen is on the stigma the sticky, sugary solution ( indicates that ovules are mature and ready for fertilisation) stimulates the pollen to grow a pollen tube.• This pollen tube is the path through which pollen travels to the ovule.
•The pollen enters the ovule through the micropyle.•The male gamete unite with the female gamete. This is known as fertilisation.
After Fertilisation
• After fertilisation takes place the ovule becomes a seed and the ovary becomes the fruit.
Seed
Plumule Radicle
Cotyledon
Embryo
Parts of SeedI. TestaII. PlumuleIII. RadicleIV. Cotyledon
Testa/ Seed Coat
• It is a hard covering which the seed develops to protect the embryo.
Testa
Plumule and Radicle
•Plumule is the part of the seed which grows to a shoot/ stem.•Radicle is the part of the seed which grows to a root.
Cotyledon•The cotyledon stores the minerals which the needs to germinate.
Germination• The plant need special conditions so that it can germinate.
•Conditionsi. Waterii. Oxygeniii. Warm temperature
Seed DispersalSeed
Dispersal
Mechanical
Dispersal
Wind Self Water
Zoological
Dispersal
Animal
Why dispersed?
•Plants can’t grow in an overcrowding condition or in their parents’ shade. Seeds have to be dispersed so that they can germinate properly.
Wind Dispersal• Seeds that are wind dispersed are usually light in weight and have wing like structures which will help them to scatter by the wind.
• E.g. Sycamore
Water Dispersal
Plants that are water dispersed should float and should have a waterproof case. It also should be hollow.
E.g. Coconut
Self Dispersal•Some fruits becomes so dry so as a result the fruit explodes and the seeds are scattered away from the parents.
• E.g. Witch hazel
Animal Dispersal
•Seeds that are animal dispersed are usually spiky, large and sticky. Some seeds are released during excretion.
• E.g. Hooked Fruits
FruitsFruits
Simple
Fleshy Fruits Dry Fruits
Aggregate Multiple
Simple Fruits•Simple fruits form from a carpel.
Simple
FruitsFlesh
y Fruits
Dry Fruits
Aggregate Fruits
•These are formed by fusion of a pistil of one flower.
• E.g. Cherimoya
Multiple Fruits•These fruits are formed by fusion of several separate pistils of several grouped flower.
•E.g. Fig
False Fruits•Some fruits, such as apples, are called false fruits because their fleshy part does not grow from part of the flower but from the receptacle on which flower grows.
Asexual Reproduction
• It occurs only with one parent and offspring produced are genetically identical to their parent.
Ways of asexual reproduction
Ways of asexual
reproduction
Runners Tubers Bulbs
Runners •These are side branches of some plants that grow along the surface of the soil. Roots grow down from buds on the runners. These develop into a new plant.
•E.g. Strawberry
Tubers•A swollen, fleshy, usually underground stem of a plant, such as the potato, bearing buds from which new plant shoots arise.
• E.g. Potatoes
Bulbs• A short, modified, underground stem surrounded by usually fleshy modified leaves that contain stored food for the shoot within: an onion bulb.
•E.g. Onion
Advantages of sexual and asexual reproduction and their disadvantages
Type of reproductio
n• Sexual
• Asexual
Advantages
• Shows genetic variation
• More offspring produce
Disadvantages
• Few offspring produce
• No genetic variation
Artificial Reproduction
Artificial Reproducti
on
Grafting Cutting Cloning
Grafting•This method involves making a cut into the stem of a tree. A small stem from another tree which has buds is fitted into the cut.
Cutting•This method involves cutting small piece of the stem which has leaves, the cutting is then placed in water until roots develop. Then this plant is place in the soil and develops into a new plant.•To speed up the process hormone rooting powder can be used.
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You!!