Plant Reproduction Click to Enter Plant Reproduction Home

Plant Reproduction Click to Enter

Plant Reproduction Home Page 4 1 Seed dispersal Flower structure 5 2 Germination Pollination 3 6 Fruit development Test

Flowers are the reproductive organs of plants Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Click image to view a video on plant reproduction If the hyperlink does not work then copy and paste this url into a new browser window and you can watch the video then, url: http: //vimeo. com/1594037? pg=embed&sec=1594037 Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Flower structure stigma anther style stamen filament ovary ovule petal sepal peduncle Flower Structure Pollination Fruit Development receptacle Seed Dispersal Germination Test carpel

Structure and function of the flower stigma anther style stamen filament ovary ovule petal sepal receptacle peduncle Flower Structure Pollination Fertilisation Seed Dispersal Germination Test carpel

Flower Structure Quiz • What is the name of the structure labelled X in the diagram? carpel sepal X stamen peduncle Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Flower Structure Quiz • Where is pollen made? stigma sepal anther ovary Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Flower Structure Quiz • Where is the ovule found in a flower? petals style nectary ovary Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Flower Structure Quiz • Which parts of the flower are labelled below: X X = style, Y = stigma X = filament, Y = anther Y X = stigma, Y = style X = anther, Y = filament Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination The pollen grain contains the male sex cell (gamete) Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination is the transfer of pollen from the anther to the stigma • This is an example of cross-pollination as the pollen travels from one flower to a different flower. This is desirable in plants as it promotes variation. Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollen can be carried between flowers by insects or by wind Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Insect-pollinated flowers are adapted to attract insects to them to enable transfer of pollen Pollen has barbs for hooking onto insect fur nectar and a scent present Anthers positioned to rub pollen onto insects Sticky stigma to collect pollen Flower Structure Pollination Brightly coloured petals Fertilisation Seed Dispersal Germination Test

Wind-pollinated flowers are different in structure because they do not have to attract insects to them but do need to be exposed to the wind. Pollen grains are very small and light. They occur in very large numbers Anthers are exposed to the wind so that pollen can easily be blown away Stigma are feathery to catch pollen carried on wind Petals are small and green as there is no need to attract insects Flower Structure No scent or nectary Pollination Fertilisation Seed Dispersal Germination Test

Self-pollination occurs when pollen falls from the anther onto the stigma of the same flower • Self-pollination is not desirable as it reduces variation Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Flowers will prevent self-pollination by either having stigma above stamen or… Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

…by having stamen and stigma mature at different times. Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Click on the icons below to view the summary videos on pollination If the hyperlink does not work then copy and paste this url into a new browser window and you can watch the video then, url: http: //www. youtube. com/watch? v=b. Z 3 J 4 UWwd 2 Q Pollination (9 minutes) If the hyperlink does not work then copy and paste this url into a new browser window and you can watch the video then, url: http: //www. youtube. com/watch? v=ge 3 EM 8 AERV 0 Insect pollination (1 minute) Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination Quiz • Pollination is the transfer from…. ? the stigma to anther style to stamen ovule to filament anther to stigma Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Pollination Quiz • The two mechanisms for pollination are? Wind and water Insect and wind Insect and water Wind and birds Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination Quiz • Cross-pollination… Increases variation Decreases variation Is only performed by insects Is only performed by wind Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination Quiz • Flowers are adapted for wind-pollination by… Having bright petals and a scent Having a nectary Having feathery stigmas Having sticky stigmas Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Fertilisation and Fruit Development Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Self pollination Advantages Disadvantage Self-pollination leading to selffertilization has the advantage of greater reliability, particularly where members of the species are uncommon and are separated by large distance. Self-pollination is the extreme form of inbreeding and can result in less vigorous off springs, to fight harsh or change in environment. It is also useful in harsh climate where insects are less common, such as high up on the mountains.

Cross pollination Advantages Disadvantage Cross-pollination is a form of ‘out breeding, and offers greater amount of genetic variation helping them with greater chances of survival of the off springs, against change in environment. Cross-pollination is a disadvantage particularly where members of the species are uncommon and are separated by large distance. Pollens are to be produced in large quantities and its too much wastage of pollens.

Once pollination occurs a tube grows from the pollen grain down through the style to the ovule stigma style carpel ovary ovule Note: Petals not shown in order to simplify diagram Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Fertilisation occurs when the male gamete fuses with the ovule (the female gamete) Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Watch this short introductory video to review fertilisation (1 minute) If the hyperlink does not work then copy and paste this url into a new browser window and you can watch the video then, url: http: //www. youtube. com/watch? v=p. Vh. H 2 GPlck. E

Seed Dispersal Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Watch the video on seed dispersal (lasts just under 10 minutes) If the hyperlink does not work then copy and paste this url into a new browser window and you can watch the video then, url: http: //www. youtube. com/watch? v=zb. Q 1 j. Wl 3 AOM

After fertilisation the petals, stamen and sepals fall off. The ovule turns into a seed, the fertilised egg inside develops into an embryo plant. Cotyledon: Food store Testa: tough seed coat Plumule: Embryo shoot Micropyle: Hole made by pollen tube Radicle: Embryo root Flower Structure Pollination Fruit Development Seed Dispersal Germination Test Embryo plant

Water leaves the seed, it dehydrates and becomes dormant because metabolic reactions stop. The ovary develops to become a fruit. Fleshy wall of the ovary (yes, you are eating an adapted ovary when you crunch into an apple! seed Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Seeds need to be dispersed away from the parent plant in order to reduce competition for space, light, nutrients and water. • Seeds can be dispersed by: • • Wind Water Mechanical Animals

Seed dispersal quiz • Which mechanism for dispersal is used by the seed shown in the picture water mechanical wind animal Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Seed dispersal quiz • Which mechanism for dispersal is used by the seed shown in the picture mechanical animal water wind Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Seed dispersal quiz • Which mechanism for dispersal is used by the seed shown in the picture water wind animal mechanical Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Seed dispersal quiz • Which mechanism for dispersal is used by the seed shown in the picture animal mechanical water wind Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Germination Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

The seed contains the embryo plant and cotyledons (starch stores) Testa Water enters the seed through the micropyle and activates enzymes. Plumule (embryo shoot) The water also softens the testa to allow it to split. Radicle (embryo root) Cotyledon Micropyle Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Enzymes are used in seed germination Plumule starch amylase secreted embryo plant ab so rb ed The enzymes break starch down into maltose and then glucose. The glucose is used in respiration to provide energy for growth maltose Radicle This is the first part to grow out of the seed as it needs to absorb more water Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Whilst germinating the plant uses food stores in the cotyledon to provide energy for growth light The seedling can now photosynthesise and make its own food germination Plant growth and development soil Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Changes in dry mass of the germinating seed: Seed loses weight as it uses up starch stores in the cotyledons as the seedling cannot photosynthesise yet Dry mass/g Weight increases as the seedling can photosynthesise and plant grows Dry mass is the mass of solid matter with all water removed Days Flower Structure Pollination Fruit Development Seed Dispersal Germination Test

Conditions required for germination Pyrogallol (absorbs oxygen) Oxygen present No light Oxygen present No oxygen moist 4 o C A Flower Structure dry moist Warm B Warm C Warm D Warm E Pollination Fruit Development Seed Dispersal Germination Test