Flashcards in Bio 108 - Lecture 12 Deck (29):
One Phylum of Angiosperms
- Majority of seed plants, 250 000 species
- Includes all sizes
Microsporophylls on a flower
Stamens = Anther + Filament (male)
Megasporophylls on a flower
Carpels = Stigma + style + ovary (female)
Perfect vs Imperfect Flower
Perfect: Both stamens and carpels
Imperfect: Only has either stamens or carpels
- When an imperfect flower has male and female flowers on same individual plant
mono = one
Oikos = House
When an imperfect flower has male and female flowers on different individual plants
What is a fruit?
- A mature ovary containing seeds
- The "container" part of the angiosperm
- Can be dry and thin, or thick and fleshy
How does fruit effect Seed dispersal?
Fruit aids dispersal of seeds, by either catching wind, or by catching animals
What is a Cotyledon?
- an embryonic seed leave present inside the seed
- Radicle (embryonic root) is also present in seed
Dicots vs Monocots
Dicots: Two cotyledons
Monocots: One cotyledon
What do anthers produce?
Microspores that produce male gametophytes inside pollen
What do Ovules Produce?
Ovules produce megaspores that produce female megagametophytes called embryo sac
Have many cells in a angiosperm megagametophyte?
7 cells, much smaller then gymnosperm megagametophyte
When does Polination occur?
When pollen lands on stigma
What is a polar body?
When a megagametophyte cell has two nuclei
What happens during germination?
1) The generative cells divides to form 2 sperm
2) The pollen tube grows down style to ovule in ovary, taking sperm with it
What is Double Fertilization?
1) One sperm fuses with egg and produces a 2n zygote
2) Other sperm fuses with polar bodies and becomes a triploid endosperm
What is the role of the Triploid Endosperm?
1) Takes nutrients from parent gametophyte
2) Undergoes mitosis to produce food for embryo
When did Angiosperms start appearing?
During Cretaceous and early Tertiary periods
How Cyads are like Angiosperms
- Larvae of weevil develops in male cones
- When adult weevils emerge and get dusted with pollen
- Adult weevils are attracted to sugary fluid produced by female cones
- Pollen fertilized the egg
3 Gymnosperms that reproduce like Angiosperms
3) Welwitschia Mirabilis
Some Characteristics of Gymnosperms being related to Angiosperms
- Some gymnosperms reproduce by double fertilization.
- Each sperm gets fertilized, but as zygote grows, the, other aborts
3 Advantages to Angiosperm - Style Fertilization
1) Food store for seed develops only after fertilization
2) Female gametophyte reduced in size and is cheaper to produce
3) Production of female gametophyte takes only a few days rather then months
What is the oldest angiosperm?
6 Main Differences between Monocots and Eudicots
1) 1 vs 2 Cotyledons
2) Parallel vs Netlike Veins
3) Scattered vs Ring-like vascular tissue
4) Fibrous root vs taproot
5) 1 vs 3 openings in pollen
6) Flower parts in 3's vs 4's or 5's
A monophyletic subset of dicots