* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Plant Reproduction
Survey
Document related concepts
Plant breeding wikipedia , lookup
Plant nutrition wikipedia , lookup
Plant secondary metabolism wikipedia , lookup
Plant physiology wikipedia , lookup
Evolutionary history of plants wikipedia , lookup
Plant ecology wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Plant morphology wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
Ecology of Banksia wikipedia , lookup
Gartons Agricultural Plant Breeders wikipedia , lookup
Perovskia atriplicifolia wikipedia , lookup
Pollination wikipedia , lookup
Flowering plant wikipedia , lookup
Transcript
* Flowers Seeds Pollination Germination *In order for plants to be successful in many different environments they must be able to reproduce themselves. *The reproductive patterns of plants reflect the reproductive patterns of any other organism. * *Male must meet female in some way. *Male reproductive cells are smaller, numerous and motile (able to move). *Female reproductive cells are large, single and sessile (not able to move) *A plant will spend most of it’s time and energy on making sure that the ovuole is taken care of as there is only one per flower. *Some flowers are only female, some flowers are only male and some flowers have both male and female gametes (pollen and ovuole). *These flowers are considered hermaphroditic (can fertilize themselves). *A flower is a specialized shoot with four circles of modified leaves: sepals, petals, stamens, and carpals. Fig. 30.13a *The sepals at the base of the flower are modified leaves that enclose the flower before it opens. *The petals lie inside the ring of sepals. *These are often brightly colored in plant species that are pollinated by animals. *They typically lack bright coloration in wind-pollinated plant species. *Neither the sepals nor petals are directly involved in reproduction. * Stamens, the male reproductive organs, produce microspores (pollen) that will give rise to gametophytes (new plants). *A stamen consists of a stalk (the filament) and a terminal sac (the anther) where pollen is produced. *Carpals are female reproductive organs that produce megaspores (ovuole) and their products, female gametophytes. *At the tip of the carpal is a sticky stigma that receives pollen. *A style leads to the ovary at the base of the carpal. *Ovules and, later, seeds are protected within the ovary. * Fruits are produced by the ovary developing. The fruit will protect the seeds and aid in dispersal. Fruits in angiosperms include vegetables and fruits. * Plants use pollination as a way to reproduce. * As the pollen matures, the anther bursts open releasing all the pollen. * This is carried to the stigma of the same or other flowers. * Process is called pollination * Definition: transfer of pollen from anther to stigma * *There are 2 types of pollination: *1) Self Pollination – is when the pollen of one flower falls on the stigma of the same flower or another flower of the same plant. *2) Cross Pollination – is the transfer of pollen from the stigma or one flower to the anther of a flower of another plant of the same species. *Cross Pollination can be by wind or animals but mostly insects. * *During fertilization, the pollen nucleus fuses with the female nucleus to produce the zygote. *The zygote grows into the seed. *The ovary grows into the fruit – different adaptations for seed dispersal. *Fruit forms from concentration of nutrients * *Fruits can be dry – roses, dandelions or peas. *Fruits can be juicy – apples, cherries or plums. * * *Seed and Fruit Dispersal results in the spreading of fruits and seeds to other environments and ecosystems. *Important because: *1) The seeds will not overcrowd in an area and this minimizes competition for resources. *2) It spreads the seeds to other environments which might offer better chances of survival for these plants. * Fruits – Seed dispersal - Wind Fruits – Seed dispersal - Water Fruits – Seed dispersal - Animals * Internal/External Structure, Metabolic events and Needs for Germination – Why do we have seeds? *Plumule: develops into the stem. *Cotelydon: stores or absorbs food for the developing embryo. *Radicle: first part of a seedling (a growing plant embryo) to emerge from the seed during the process of germination – primitive root *Micropyle: small pore on the seed coat for absorption of water. *Testa: outer seed coat, protective layer * * *1) Water is needed to: *Activate hormones and enzymes *Swelling of the seeds = bursting of seed coat. *Transport of simple materials to the embryo – to be used for respiration and growth. *Metabolic and enzyme actions – occur in solution, therefore need water. *Conversion of storage compounds into simple components (i.e. starch to glucose) * *2) Oxygen is needed for aerobic respiration. *Without a supply of oxygen, seeds fail to germinate because of the lack of energy – in the form of ATP. * *3) Suitable temperature *All reactions (in germination) are controlled by enzymes. *Optimal temperature for enzyme activity leads to faster rate of germination. *Freezing = inactivates enzymes *Very high temperatures = denatures enzymes * *1) Water enters the seed through a hole in the seed coat – microplye. *2) Water moves into the tissues and cells by osmosis. *3) The seed swells and the seed coat bursts. *4) Water activates gibberelline, the hormone needed for breaking the dormancy of the seed. * *5) Gibberelline activates amylase which catalyzes the break down of starch to maltose to glucose. *6) Glucose is mobilized (transported) to the embryo. *7) Embryo absorbs glucose and uses it for respiration (oxygen needed). *8) Cell division, growth and elongation occurs in the embryo = radicle to root, plumule to stem. * *9) Nutrients needed for growth all supplied by food stored in cotelydons. *10) As nutrients are consumed, first leaves start to appear = photosynthesis. *11) When photosynthesis starts, seedling absorbs water and minerals from the soil, Co2 from the atmosphere and sunlight. * * Starch, Proteins and Lipids * Plants make glucose in the process of photosynthesis. * Glucose is used for respiration to produce energy which powers different processes in the plant such as active transport. * Excess glucose can be converted to storage materials. * *There are 3 main types of storage materials: *1) Starch *2) Proteins *3) Lipids * *Examples include: * Corn seeds * Potato tubers * Rice and wheat grains * *Examples include: * Seeds of leguminous plants: * Peas * Beans * Lentils * *Examples include: * Olive fruits and seeds * Sunflower seeds *