reproduction in plants

me when plants have more game than me

Describe the features of an insect pollinated flower that helps it attract insects

Describe the features of an insect pollinated flower that helps it attract insects

- Large petals - attract insects

- Coloured petals - attract insects

- Scent - makes insects push past stamen

- Nectar - makes insects push past stamen

- Sticky pollen grains - attach to insect

Describe the features of a wind pollinated flower

• Exposed stamens - allows pollen grains to be easily released

• Feathery stigma - catches drifting pollen grains

• Small petals - allows stamens and stigmas to be exposed

• Small pollen grains - easily carried by the wind

Describe the events that lead to seed formation

• Pollen lands on stigma

• Pollen tube grows down style into ovary

• Male gamete (pollen) fuses with female gamete (egg)

• Ovule => seed

• Ovule wall => seed coat

• Ovary => fruit

Describe the structure of a seed

Plumule

Padicle

Cotyledon (Food store)

Testa (Seed coat)

What is germination?

• Food store in seed is used up

• Radicle grows down

• Plumule grows up towards light and starts photosynthesis

What conditions are needed for germination?

• Water - to activate enzymes

• Oxygen - for respiration

• Warm temperature - optimum temp for enzyme controlled reactions

Describe an investigation into the factors required for germination

• Set up 4 test tubes, each containing 15 seeds on cotton wool

  • In one test tube (A) leave cotton wool dry

  • In one test tube (B) add water to cotton wool, to make it moist

  • In one test tube (C) add water to cotton wool, then add a later of oil on top to prevent oxygen diffusion to the seeds

  • In one test tube (D) add water to the cotton wool to make it moist, then place it in the fridge

  • Leave tubes A B and C at room temperature

  • Leave all tubes for a set period of time, like 5 days

  • Compare results and see which tube has the greatest number of germinated seeds

Which test tube would you expect to see the greatest number of seeds germinating?

• B

  • only tube providing water, oxygen and warmth

  • all others missing at least one vital factor

Give the independent variable for this investigation?

Number of seeds germinating after 5 days

Give control variables for this investigation

• Temperature of tubes A B C

• Species of cress seeds used

• Parent plant of cress seeds

• Type of water used (boil first and then cool)

• Light intensity

Give examples of natural asexual reproduction in plants

• Strawberry runners

• Tubers

Describe how strawberry runners reproduce asexually

• Runners = horizontal stems growing sideways from parent plant

• When runners touch the soil, plantlets grow roots

• New plantlets grow and become independent from parent plant

Give an example of an artificial method of asexual reproduction in plants

• Taking a cutting

Describe the process of taking a cutting

• A piece of a plants stem is cut off

• Dipped in rooting powder with plant growth hormones

• Transferred to soil

• Grow into genetically identical plants