algae and land plants Flashcards
what are plants
Eukaryotic, photosynthetic organisms include green algae, mosses, ferns, gymnosperms, and angiosperms.
What is the connection between green algae and land plants?
Green algae are the ancestors of all land plants. They share key features like chlorophyll a and b, starch storage, and similar chloroplast structures.
Why did plants move to land?
to access more sunlight and CO₂, and to escape competition in aquatic environments. Adaptations like cuticles, stomata, and vascular tissue allowed them to survive on land.
What is the cuticle, and why is it important?
A waxy layer on the surface of leaves and stems that prevents water loss. It helps plants survive in dry terrestrial environments.
What are stomata, and what is their function?
Tiny pores on leaves that open and close to regulate gas exchange (CO₂ in, O₂ out) and minimize water loss.
What is vascular tissue, and what are its two main types?
Vascular tissues are tubes that transport water, nutrients, and sugars throughout the plant. The two types are:
Xylem: Transports water and minerals from roots to leaves.
Phloem: Transports sugars from leaves to other parts of the plant.
What is sporopollenin, and why is it important?
A tough outer coating that protects spores and pollen from drying out. It was a key adaptation for reproduction on land.
What are gametangia, and what are the two types?
gametangia are specialized structures that protect gametes (sperm and eggs) from drying out
- antheridia: protects sperm
- archegonia: protects eggs
What is the alternation of generations?
A life cycle that alternates between two multicellular stages:
Gametophyte (haploid): Produces gametes (sperm and eggs) through mitosis.
Sporophyte (diploid): Produces spores through meiosis.
What is the role of the sporophyte in the plant life cycle?
The sporophyte is the diploid (2n) stage of the plant life cycle. It produces haploid spores through meiosis, which grow into gametophytes
What is the role of the gametophyte in the plant life cycle?
The gametophyte is the haploid (n) stage of the plant life cycle. It produces gametes (sperm and eggs) through mitosis, which fuse to form a diploid zygote.
state the basic structures of plants (roots, shoots and leaves, vascular tissues, flowers, fruits and seeds)
roots: collects water and nutrients from the soil
shoots and leaves: not all the tissues in plants photosynthesize. gathers sunlight and CO2
vascular tissues: links roots and shoots, transports water, sugars, nutrients
flowers, fruits and seeds: reproduction and dispersal
what are non-vascular plants, what are some examples and characteristics
-Called Bryophytes. eg, mosses, liverworts, hornworts
- Plants that lack vascular tissue (xylem and phloem). Examples include mosses, liverworts, and hornworts. They are small and live in moist environments. They reproduce using spores, not seeds
characteristics:
- rely on diffusion and osmosis for water and nutrient movement movement
- small and low growth due to a lack of support structures
What is the ecological importance of plants?
Plants are primary producers, produce oxygen, store carbon, stabilize soil, and form the base of terrestrial food chains. They also provide food, fuel, fibre, and medicines for humans.
detailed answer:
Primary producers: Plants form the base of terrestrial food chains by converting sunlight into energy through photosynthesis.
Oxygen production: Plants produce oxygen via photosynthesis, essential for life on Earth.
Carbon storage: Plants absorb CO₂ from the atmosphere and store carbon, helping to regulate the climate.
Soil stabilization: Plant roots prevent soil erosion and improve soil health.
Human uses: Plants provide food, fuel, fibre, building materials, and medicines.
What are seed plants, and what are the two main groups?
Plants that produce seeds for reproduction. The two groups are:
Gymnosperms: Plants with naked seeds (e.g., pine trees).
Angiosperms: Flowering plants with seeds enclosed in fruit (e.g., roses, oak trees).
Seedless Vascular Plants
Examples: Ferns, horsetails.
Have vascular tissue for water and nutrient transport.
Reproduce using spores, not seeds.
