Division Angiosperm Flashcards
What does the term ‘angiosperm’ mean?
The word ‘angiosperm’ comes from Greek words meaning ‘vessel’ and ‘seed,’ referring to plants with seeds enclosed in an ovule.
What are angiosperms?
Angiosperms are vascular plants that produce flowers and enclosed seeds within an ovule.
Why are angiosperms considered the most successful land plants?
They can survive in all habitats, produce flowers, fruits, and seeds, and exhibit greater adaptability than other vascular plants.
What does ‘siphonogamy’ mean?
Siphonogamy is the condition where plants develop pollen tubes for transferring male gametes to the egg.
Why are angiosperms classified as siphonogamous?
Because they use pollen tubes to transfer sperm, unlike lower plants where sperm cells swim to the egg.
List three key survival factors for angiosperms.
- Ability to adapt to various habitats.
- Production of flowers, fruits, and seeds.
- Greater plasticity and variability than other vascular plants.
What adaptations help angiosperms survive in different environments?
Ability to grow in various soils, temperatures, and climates. Symbiotic relationships with fungi and parasites.
Name some examples of flowering plants.
Okra, Thevetia, Flamboyant, Pride of Barbados, Beans, Groundnut, Mango.
Into what two classes are angiosperms divided?
- Dicotyledonae (Dicots)
- Monocotyledonae (Monocots)
Give examples of monocots and dicots.
Monocots: Maize, Rice, Wheat.
Dicots: Beans, Mango, Groundnut.
What are the main parts of a flower?
- Stamen (Androecium) – Male reproductive part.
- Carpel (Gynoecium/Pistil) – Female reproductive part.
- Sepals (Calyx) – Protects the flower bud.
- Petals (Corolla) – Attracts pollinators.
What are the parts of the stamen?
- Filament – Slender stalk.
- Anther – Stores and produces pollen grains.
What are the parts of the carpel?
- Stigma – Mouth of the carpel, receives pollen.
- Style – Connects stigma to ovary.
- Ovary – Contains ovules.
What is pollination?
The transfer of pollen from the anther to the stigma.
Name three pollination agents.
Wind, water, and insects (e.g., bees, butterflies).
What is cross-pollination vs. self-pollination?
Cross-pollination: Pollen transfers between flowers of different plants.
Self-pollination: Pollen falls on the stigma of the same flower or plant.
What happens after pollination?
The pollen tube grows down the style, two sperm cells travel through the tube, one fertilizes the egg (forming the zygote), and the other fuses with the polar nuclei (forming the endosperm).
What is double fertilization?
- One sperm fertilizes the egg, forming a zygote.
- The second sperm fuses with two polar nuclei to form a triploid endosperm, which nourishes the seed.
What is alternation of generations?
A life cycle in which plants alternate between a diploid sporophyte and a haploid gametophyte phase.
What are microspores and megaspores?
Microspores: Develop in the anther and become pollen grains.
Megaspores: Develop in the ovary and become ovules.
What is an embryo sac?
The female gametophyte containing the egg cell, synergids, antipodal cells, and polar nuclei.
What happens to the ovary and ovule after fertilization?
The ovary becomes the fruit, and the ovule becomes the seed.
How do monocots and dicots differ in seed structure?
Monocots: One cotyledon.
Dicots: Two cotyledons.
How do monocots and dicots differ in leaf venation?
Monocots: Parallel venation.
Dicots: Net-like venation.
