Chapter 14 - Plant Reproduction Flashcards
Asexual reproduction
New individuals are formed from only one parent
What are runners?
Asexual reproduction where the plant produces special stems called runners. At a certain distance runner forms a new root and new shoot
Sexual reproduction
To sex cells unite
Gamete
A sex cell
Sexual reproduction in plants involves…
i) Pollination
ii) Fertilisation
iii) Seed and fruit formation
iv) Seed and fruit dispersal
v) Germination
What is the function of the sepals?
Protect the flower when it is a bud
What is the function of the petals?
Protect the internal parts of the flower. In many plants the petals are brightly coloured to attract insects
What is the function of the carpel?
The female part of the flower.
- Each carpel produces the egg cell.
- The nucleus of the egg is the female gamete.
- Some have more than one carpel
What is the function of the stamen?
The male part of the flower.
- Produces pollen grains.
- The nucleus in the pollen grain is the male gamete.
- Most flowers have a large number of stamens
What parts of the flower make up the carpel?
○Stigma ○Style ○Ovary ○Egg ○Ovule
What parts of the flower make up the stamen?
○Filament
○Anther
What is the function of the stigma?
Place where pollen grains will land
What is the function of the style?
Connects the stigma to the ovary. In some plants the style is very short
What is the function of the ovary?
Contains one or more ovules. Each ovule produces an egg. The nucleus of the egg is the female gamete
What is the function of the filament?
Stalk that supports the anther. Ensures the anthers are high up in the flower, so pollen can leave easily
What is the function of the anther?
Makes pollen grains. The nucleus in each pollen grain is the male gamete
Pollination
The transfer of pollen from a stamen to a carpel
What are the agents used for pollination?
Wind and insects
Fertilisation
Joining of the male and female gametes to form a zygote
How does fertilisation take place?
- Pollen carried to top of carpel
- Pollen forms tube which grows down through carpel
- Pollen nucleus, male gamete, passes down pollen tube.
- Male gamete joins to nucleus of egg, female gamete
- Fertilisation takes place in base of carpel
- Zygote will grow to form seed
- Seed consists of young plant surrounded by food supply
- Seed or seeds become surrounded by another food supply called fruit
The embryo of a plant consists of…
○Plumule
○Radicle
What is the plumule?
Will form the future shoot of a plant
What is the radicle?
Will form the future roots of a plant
Dispersal
The carrying of a seed as far as possible from the parent plant
Why are seeds dispersed far from the parent plant?
Reduces competition between the seedlings and parent plant for light, space, water and minerals
What are the main methods of seed dispersal?
○Wind
○Animal
○Self dispersal
○Water
Describe wind dispersal
The seeds are often small and light, or have special devices so the wind can carry them further. e.g Dandelions have a ‘parachute’ and sycamore seeds have wings like helicopters
Describe animal dispersal
There are two ways:
- Swallow the fruit (and seeds). The fruit is digested and the seeds are passed out sometime later. e.g Blackberries
- Fruit/seeds stick to the animal and are carried away to fall off later. e.g Burdock
Describe self dispersal
Usually involves the fruit (pod) bursting open when ripe meaning the seeds are flung as far away as possible
Describe water dispersal
Some fruits/seeds are able to float. This allows them to be carried away by streams, rivers and ocean currents e.g coconuts
Germination
The growth of a seed to form a new plant
What are the conditions necessary for germination?
Water, oxygen and a suitable temperature
