Flowering Plants
description
Transcript of Flowering Plants
Flowering Plants
ByNeil Bronks
The Parts of a Flower
• Most flowers have four parts:
• sepals,• petals,• stamens,• carpels.
The parts of a flower
• Sepals protect the bud until it opens.
• Petals attract insects.
• Stamens make pollen.
• Carpels grow into fruits which contain the seeds.
Stamen (male)
• Anther: pollen grains grow in the anther.
• When the grains are fully grown, the anther splits open.
Pistil (female)
• Stigma• Style• Carpel (ovary)• Ovules (eggs)
Parts of a Flowering Plant
Male Parts
Anther
Filament
Together called the STAMEN
Female Parts
Stigma
Style
Ovule
Ovary
Together called the CARPEL
Pollination• Flowering plants
use the wind, insects, bats, birds and mammals to transfer pollen from the male (stamen) part of the flower to the female (stigma) part of the flower.
Pollination
• A flower is pollinated when a pollen grain lands on its stigma.
• Each carpel grows into a fruit which contains the seeds.
Fertilisation
• Fertilised ovules develop into seeds.
• The carpel enlarges to form the flesh of the fruit and to protect the ovary.
PollenPollen is produced in the ANTHER
The anther explodes and pollen just goes everywhere
Some of the pollen sticks on the STIGMA
The pollen goes down a small tube to the EGG
There are lots of eggs in most plant ovaries.
Pollen Sexual reproduction is where two different cells meet
Sex cells are called GAMETES
Pollen is the male gamete
The female gamete is the EGG
When the pollen and egg meet this is called FERTILISATION
Ways to Scatter Pollen
Wind Insect
Wind Scattered Pollen
Anthers
Outside
Carry a large amount of very small pollen.
Petals
Small and green
No Scent or Nectar
Examples-
Grass
Oak Trees
Wind pollination
• Some flowers, such as grasses, do not have brightly coloured petals and nectar to attract insects.
• They do have stamens and carpels.
• These flowers are pollinated by the wind.
Insect Scattered PollenPetals
Colourful
Scented
Contain sweet liquid called
NECTAR
Anthers contain a small amount of large pollenExample
Roses
Dandelions
Fertilisation
When the male gamete POLLEN
Gets inside the female gamete or EGG
They form a ZYGOTE
This is the first cell of a new plant
Zygote
• The zygote grows to form a baby plant
• The first cells divide and form an EMBRYO
Zygote
• The embryo starts to become a root
• If the flower has lots of ovules it makes lots of seeds (Apples)
Seed or Fruit Formation
Testa
Food Supply(OIL and STARCH)
Plumule (Stem)Radicle (Root)The two together make the
EMBRYO
Germination – When?
Seeds Germination
Lateral roots form
Next the shoot grows up to the light
Embryo becomes primitive root
The first leavesZygote
forms here
Wet and warm conditions
Seed dispersal
Seeds are dispersed in many different ways:
• Wind• Explosion• Water• Animals• Birds
Seed DispersalThe carrying of the seed (and its surrounding fruit) as far away from the parent plant as possible
WIND
Dandelion
Sycamore
ANIMALS
EATEN
Berries
STICKY
Thistles
SELF DISPERSAL
Fruit Wall (Pod)
Pod bursts and flings seeds out
WATER DISPERSAL
A floating seed is carried by sea or river
How birds and animals help seed dispersal
• Some seeds are hidden in the ground as a winter store.
• Some fruits have hooks on them and cling to fur or clothes.
How birds and animals help seed dispersal
• Birds and animals eat the fruits and excrete the seeds away from the parent plant.
Asexual ReproductionA plant produces another plant without involving a second plant
No gamete cells are used.
The plant sends out runners
Summary
H/Wp 188-190
Q 5,6,9,11,12,15