reproduction in flowering plants

carinazainatul 11,490 views 23 slides Oct 26, 2014
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REPRODUCTION IN FLOWERING PLANTS

The Parts of a Flower In a typical flower, there are four main parts: Petals, sepals, stamen and carpel. There are two main types of flower: Insect- pollinated flowers Wind- pollinated flowers Chapter 2 reproduction in flowering plants

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

What is the name of the structure labelled X in the diagram? sepal stamen peduncle carpel X

Flower Structure Quiz Where is pollen made? stigma sepal anther ovary

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

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

1. Petals (corolla): often with bright color, pattern and scent to attract insects and birds. 2. Carpels(female gametes) : Stigma :sticky surface that collects pollen Style : a neck that joins the stigma to the ovary Ovary : part of the ovary that produces ovules

3. Stamen (male gametes): anther :head of the stamen that contain pollens grain Filament : long stalk to supports the anther 4. Sepals ( calyx) : leaves that protect the young flower buds

Pollen can be transported from the anther to the stigma by insects, birds o r other animals, wind and water ,

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

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. Petals are small and green as there is no need to attract insects Stigma are feathery to catch pollen carried on wind Anthers are exposed to the wind so that pollen can easily be blown away Pollen grains are very small and light. They occur in very large numbers No scent or nectary

Self-Pollination and Cross-pollination Self –pollination : if the pollen goes from an anther to the stigma of the same flower or other flowers on the same plant. Cross-Pollination : it the pollen goes from an anther to stigma of a flower on other plant of the same species.

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 Click to show animation of self-pollination Flower Structure Pollination Fertilisation Seed Dispersal Germination Test

Pollination Quiz Pollination is the transfer from….? the stigma to anther style to stamen anther to stigma ovule to filament

Pollination Quiz The two mechanisms for pollination are? Wind and water Insect and water Insect and wind Wind and birds

Pollination Quiz Cross-pollination… Increases variation Decreases variation Is only performed by wind Is only performed by insects

Pollination Quiz Flowers are adapted for wind-pollination by… Having feathery stigmas Having a nectary Having bright petals and a scent Having sticky stigmas

Fertilisation When a pollen grain reaches the stigma, a small tube forms and grows down into the ovary. The pollen cells travel down this tube until they reach the ovary. When a male pollen cell reaches the ovary, it joins with a female ovule to fertilise it.

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

Fertilisation occurs when the male gamete fuses with the ovule (the female gamete) Complete the fertilisation section of the worksheet (you will need to refer to your text book) Flower Structure Pollination Fruit Development Seed Dispersal Germination Test Click to view the animation

Dispersing the fruits and seeds A plant produce many fruits. If they were all fall to the ground around their parent, they would compete with each other for light, water and minerals in the soil, and so many would die. Over crowding is prevented by fruit and seed dispersal .

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
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