Plants Summary Notes Int 1

Lasswade High School Centre Biology

Intermediate 1

Plants Summary Notes 1 Seed part Embryo plant Food store Seedcoat

Function Grows into new plant Provides energy for growth Protects seed

Germination – when a seed starts to grow.

Conditions of germination: - oxygen, water, and warmth.

Dormancy – when seedsdo not grow until conditions are suitable.

Photosynthesis – processwhere plants make their own food.

Plants absorb sunlight in their leaves with the chemical called chlorophyll . Sun is the energy needed to start photosynthesis. Sugar is stored as starch. Water enters plant via roots.

Equation: Carbon dioxide + Water  Oxygen + Sugar

Sowing Seeds SeedSize Small Medium Large

Method of Sowing Mixed with silver sand, or pelleted to space them out Scattered between thumb and finger Placed out

Pelleted seedsare wrapped in clay, and can sometimes contain chemicals.

Chitting or pre-germination – starting a seed to grow before sowing. This helps seedswith tough seed coats. It involves cutting the seedc oat with a file or knife.

Watering Automatic watering systems; 1. Trickle irrigation (pipe from a water tank supplies water to plants).

2. Capillary matting (mat which absorbs water) 3. Water retentive gel (gel beads which store water) Too much water – leaves becomesoft, yellow, and rotten, compost becomesgreen and slimy.

Too little water – brown and dry leaves.

Compost

Main part Other parts

Loam Compost Loam (soil) Peat (holds water) Sharp sand/perlite (drainage) Fertiliser (nutrients)

Loamlesscompost Peat (holds water) Sharp sand/perlite (drainage) Fertiliser (nutrients)

Rooting compost – 1 peat : 1 sand Potting compost – 3 peat : 1 sand Nutrients needed by plants are : Nitrogen (N) for leaf growth, Phosphorus (P) for root growth, and Potassium (K) for fruit development Pricking out – to give seedlings more spacefor growing.

Potting on – roots too big for pot, re-potted to bigger pot for more room.

Lasswade High School Centre Biology

Intermediate 1

Plants Summary Notes 2 Vegetative propagation – plant grown from only one parent.

Bulbs – food store, buds develop into new bulbs.

Tubers – swollen food store on roots, which can grow into new plant.

Runners – stem from baseof parent plant, with plantlet at end.

Plantlets – baby plants on leaf edge which can grow into new plant.

Offsets – plantlets produced as side shoots at base of parent plant.

Stem cuttings – part of stem cut below a node, which can grow into new plant.

Leaf cuttings – part of leaf which can grow into new plant.

Propagator – heated box, reducing water loss from cuttings. Putting cuttings in a polythene bag can also prevent water loss.

Layering – cut part of stem, and peg down to produce new plant.

Monitoring Environmental Conditions Temperature • Max/min thermometer to show highest, and lowest temperatures of the previous day.

• Thermostat controls temperature and keeps it steady, making sure it is not too hot or cold.

Greenhouses,polythene tunnels, and clochescan be used for protecting plants from cold, wind, rain, and frost.

Humidity • Amount of water vapour in the air • Higher the temperature, higher the humidity • Measured using a wet and dry thermometer, or hygrometer Ventilation • Good ventilation allows control of temperature and humidity.

• Can be controlled by window cylinders and fans fitted to a thermostat.

Pests

• •

Include greenfly (aphids), ants, spiders, slugs, snails, botrytis (fungal disease) etc.

Can be controlled by good hygiene (e.g., washing tools), or using chemicals to kill pests.

Types of Plants Different plants need different conditions to grow.

Flowering plants – moderate light and water needed, removing dead flowers (“deadheading”) encouragesmore flowers.

Ferns – damp, dull areas.

Foliage plants – grown for attractive leaves, need moderate light and water.

Succulent plants (cacti) – hot, dry, and sunny areas, they can store water in their leavesor stems.