Plant and Animal Reproduction Flashcards
What 3 factors are required for germination? (3)
Moisture from the soil, oxygen and the right temperature.
Describe the stages of germination (4)
When a seed has found the right conditions it breaks open and it sends out a root and a green shoot. This is called germination.
The root grows down to take up nutrients from the soil and the shoot grows up towards the sunlight to become a stem. The seed becomes a seedling.
As this happens the plant is using the food store in the seed to grow, but as leaves begin to form, the plant can start making its own food in a process called photosynthesis.
What are the male and female parts of the plant and what is their function? (7)
Sepals: Protect the unopened flower bud
Petals: May be brightly coloured and scented to attract insects:
Stamens: The male parts of the flower consisting of the anther held up on the filament
Anthers: Produce male gametes (in pollen grains)
Stigma: The top of the female part of the flower which collects pollen grains
Ovary: The bottom of the female part of the flower, produces the female gametes (in ovules)
Nectary: May be present to produce sugary nectar to attract insects
Define and describe the stages of Pollination, Fertilisation and Seed Formation. (4)
Pollination is the transfer of pollen grains from an anther to a stigma. Pollen can be transferred by an animal or by the wind.
Fertilisation takes place inside the ovary when the nucleus of pollen grain fuses with the nucleus of an ovule to produce a zygote.
Shown below are the steps involved in pollination, fertilisation, and seed formation of a flowering plant.
Step one: After pollen has landed on the stigma, it grows a pollen tube down through the style to the ovary.
Step two: The nucleus of the pollen grain travels down the pollen tube and fertilises the nucleus in the ovule.
Step three: The fertilised ovule develops into a seed. The seed contains the plant embryo, which contains genetic material from both parents. The ovary develops into the fruit.
Describe the 4 methods of seed dispersal. (8)
Seed dispersal is the transport of seeds from the plant to another area in order to grow.
These are the main ways in which seeds can be dispersed:
Animals: Some plants use hooks on their fruits. These attach themselves to the fur of mammals or feathers of birds and get carried from one place to another.
Explosion: Have a pod that bursts open when ripe, throwing the seeds away.
Wind: Some plants have seeds that act as parachutes, which are carried away by the wind/Some seeds are winged. They spin like helicopters as they fall from the tree, providing a longer time for dispersal by wind.
Water: Some plants grow near rivers, lakes, streams or oceans. Their fruits or seeds fall from the plant and are carried away by the water.
Define photosynthesis and write a full word equation for the reaction. List the reactants and products. (5)
Photosynthesis is a process that occurs in the leaves of a plant and needs both chlorophyll and light energy.
During photosynthesis, the chlorophyll in leaves help convert carbon dioxide and water into the products oxygen and glucose.
The product glucose acts as a vital source of food for the plant.
Carbon dioxide, water and light are all needed for photosynthesis to take place.
Carbon Dioxide + Water —(Sunlight)–> Glucose + Oxygen
What is chlorophyll, where is it found and what is its role in photosynthesis? (2)
Chloroplasts contain a green substance called chlorophyll. This traps the light energy needed to make photosynthesis happen. Plants and algae can only carry out photosynthesis in the light.
What is the role of light in the photosynthesis reaction? (1)
The light is the fuel/energy for photosynthesis.
Where does Photosynthesis take place, which cell organelle and which part of the plant? (2)
Photosynthesis takes place inside chloroplasts which are small objects inside plant cells. It takes place in the leaves.
How is a leaf adapted to its function? (6)
Thin: Provides a short distance for carbon dioxide to move by diffusion into the leaf
Large surface area: It can absorb a lot of light
Contains chlorophyll: Traps light
Stomata: Small holes in the underside of the leaf that allow carbon dioxide and oxygen to move in and out of the leaf by diffusion
Guard cells: To open and close the stomata depending on the conditions
Network of tubes: To transport water and food
