Plant evolution and diversity

What are the plant adaptations on life on land

1. Supported by air and soil

2. Respiration through air

3. Nutrition through soil and air

4. Reproduction through air or water

What are the advantages on life on land

1. Unlimited sunlight

2. Abundance of Carbon dioxide

3. Initally, very little pathogens or herbivores

What are the disadvantages on life on land

1. Supporting their bodies in a non-buoyant medium

2. Maintaining moisture inside their cells while surrounded by air

3. Obtaining resources from both the soil and air

4. Reproducing and dispersing offspring without water

Xylem

Consists of dead cells forming pipes and conveys water and minerals from roots

Phloem

Consists of living cells and conveys carbohydrates

List the characteristics of bryophytes

Have apical meristems and embryos on parent plant

Lack true roots and leave

No lignin in cell walls = Form mats

Retain water = flagellated sperm

Characteristics of Lycophytes and Monilophytes

1. Have well developed roots

2. Rigid stems (lignin)

3. Still requires moist condition for fertilisation

4. Disperse offspring as spores through air

characteristics of seed plants

1. Facilitates wide dispersal

2. A seed is a embryo packed with a food supply within a protective covering

3. Seed plants (Gymnosperms and Angiosperms) have pollen grains to carry sperm-producing cells

Gymnosperms

Plants that have naked seeds = Not produced in specialized chambers

Usually Conifers (cone bearers)

Characteristics of seedless plants

1. Seedless plants produce flagellated sperm that need moisture to reach an egg

2. Offspring are haploid, single-celled spores that survive independently as gametophytes before producing sporophytes