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Angiosperms (6 Cards)

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1
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What are the 2 classes which 97% of all angiosperms belong to?

- Eudicotyledons (eudicots)
- Monocotyledons (monocots)

Tags: angiosperms, classes
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2
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When did angiosperms first appear? When did they become ecologically dominant?

First appeared c. 130 million years ago, during the Cretaceous period. Became dominant by 90 mya.

Tags: angiosperms, cretaceous
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3
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What are the characteristics of monocots (in terms of flowers, leaves, vascular bundles, pollen, and seeds)?

Flowers: Petals occur in multiples of 3
Leaves: Parallel venation
Vascular bundles: scattered throughout stem
Pollen: one pore, furrow
Seeds: 1 cotyledon (hence, the mono)

Tags: angiosperms, characteristics, monocots
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4
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What are the characteristics of dicots (in terms of flowers, leaves, vascular bundles, pollen, and seeds)?

Flowers: petals occur in multiples of 4 or 5
Leaves: Netlike venation
Vascular bundles: in ring around stem
Pollen: 3 pores or furrows
Seeds: 2 cotyledons

Tags: angiosperms, characteristics, dicots
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5
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Describe the angiosperm life cycle (1 - 5).

1. Microsporangia in anthers produce pollen (microspores) by meoisis.

2. Microspores germinate, form 3-nucleate microgametophytes with 2 sperm cells.

3. Megasporangia in ovules produce megaspores by meoisis.

4. Megaspores develop into 8-nucleate megagametophytes with 1 egg cell.

5. Double fertilization produces an embryo in a seed (from ovule) in a fruit (from ovary)

Tags: angiosperms, life cycles, megaspores, microspores
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6
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Describe 3 characteristics of an angiosperm seed.

1. Seed coat is from integuments of maternal sporophyte

2. Nutrition for embryo from 3N endosperms.

3. Endosperm absorbed into 1 or 2 cotyledons.

Tags: angiosperms, cotyledons, integuments, seed coat, seeds
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