Plants Reproduction Flashcards
(29 cards)
What is meant by when the seed is dormant
Period of time after seed dispersal when the seed is inactive
Seed waits for the perfect conditions for germination
Waht are the conditions required for germination?
The seed must :
absorb water through the micropyle
Absorb oxygen through the micropyle for respiration
Have a slightly warm surrounding temperature to provide the optimum condition for the enzymes involved in the process of germination
Some seeds require light to germinate Auto absorb
Why does the seed need water for germination to occur
The water has to be absorbed through the micropyle to :
Mobilise the enzymes- eg giberllin
To transport materials through xylem and phloem
To make the cells size increase through the formation of vacuoles so that the testa can split and oxygen can enter the seed to need the increasing rate of respiration
Waht is a monocotyledon
Single seed leaf /cotyledon
Undergoes endospermic germination
Eg maize seed
Are fruits
Waht is a dicotyledonous seed
One that undergoes non endospermic germination so it depends on the cotyledon as a source of food
Is a seed not a fruit
Has 2 seed leaves/ cotyledons
Waht is the process of germination of an endospermic seed
Water is imbibed through the micropyle Absorb oxygen
This activates gibberlin which is in the the cotyledon
The gibberlin is absorbed in the the outermost layer of the endosperm (‘which is full of starch ) called the aleurone layer
The aleurone layer contains amino acids stored in proteins which are released on hydrolysis of these proteins .
The amino acids erased are used in the transcription of DNA and the translation of MRNA for the formation of hydrolytic enzymes amylase and maltase.
The amylase breaks down the starch of the endosperm into maltose
The matase breaks down the morose into gluscose
The glucose is absorbed in the embryo where the plumule and the radicle use it for respiration for the production of ATP for growth
What is the food source for an endospermic seed
The endosperm which is full of starch
Waht is the food source for an non endospermic germinating seed
The cotyledon which it has two of
What is the process of germination in a non endospermic seed
Water is imbibed through the micropyle and oxygen is absorbed initially through the micropyle
More water is being taken up so casing the cells to increase in size due to the formation of vacuoles
This causes the testa to split and for eoxygen to enter the seed to need with the increasing rate of respiration
One the water has entered the enzymes are activated the enzymes amylase and maltase are secreted by the embryo plant which breaks down the starch into glucose this is absorbed by the embryo plant and is used for growth
The radicle is the frost part of the seedling to grow.
It absorbed water and minerals form the soil
It anchors the seedling to the dip through the formation of lateral roots
The the epicotyl whcih s the stem of the plume grows through vacuolation and it pull the leaves of the seed backward through the soil.
Once the leaves are out of the soil there begin to photosynthesise
Waht is the first part of a seedling to grow
The first part of a seedling to grow is the radicle which absorbs water an nutrients form the soil and anchors the seedling to the ground through the formation of lateral roots
How does the radicle anchor the sealing to the soil
OThrough the formation of lateral roots which absorb water and minerals
Whcih ares of the plant are constantly undergoing cells divisor
The shoot and root tip
Why does the epicotyl pul the seeds backward
Toe prevent damage
Waht re the parts of a dicotyledonous seed
The radicle
The plumeule
The cotyledon - huge area
The micropyle
Outer layer - testa
Waht are the different parts of an endospermic seed (‘monocotyledonous seed)
Endosperm (big area)
Aleurone
Cotyledon
Radicle
Plumule
Testa
Embryo
Waht is geminstion
The process of a plant growing form a seed
When does germination start and when does it end
Germination only benign s after water has been imbued and oxygen a has entered through the micropyle (‘for non- endosperm ) and it ends when the fist set of photosynthesising leaves are produced by which time all the food store o f the endosperm and the cotyledon is used up
What are the different types of pollination
Self pollination
Cross pollination
Waht are the different types of cross pollination
Wind pollinaition
Insect pollination
How does wind and insect pollinated flowers differ from each other
Insect :
colourful petals with nectar guides
Has sweet scent with neat tar (‘often sucrose)
Small quantity of sticky sculpted pollen
Anther inside the flower
Stigma is within the flower
Larger pollen grains
Wind pollinated flowers:
Petals are usually absent of small green and incinpsuous
No scent not nectar
anther hangs out side the flower
Large feathery stigma hangs out side the flower
Large quantities of smooth pollen
Pollen grains are small
Waht are the female parts of a flower
Carmen the carpel-
Stigma
Style
Ovary
Ovule
Embryo sac
Waht are the male parts of the flower
Stamen- anther and filament
Waht is the cell wall of a pollen grain made up of
The exine and the intine
Exine outer layer
Intine innner layer
Waht are the different parts of the anther
The anther has a line of dihesance
Tapetum- outer layer of the pollens and it provides nutrient the developing pollen sacs it later grows into to the cell wall of the developing pollen grains the feel wall prevents deescaiyon to prevent the ceels wall form drying out when begin tgtransferd to the stigma of thanother flower
