BIOL 1011 Lecture Notes - Lecture 3: Microfibril, Cuticle, Lobelia Cardinalis
20 Aug 2018
School
Department
Course
Professor
Flowering Plants & Structure and Growth of Land Plants
Overview
1. Div. Coniferophyta: recap
2. Div. Anthophyta, the Flowering Plants
a) Characteristics
b) The flower
c) Monocots & Eudicots
d) Pollination
e) Pollination syndromes
f) Life cycle & double fertilization
g) Fruit types & dispersal
3. Land Plant Structure
a) Roots and shoots
b) Cell walls
Plant evolution
Next invention
Flowers
PLANT EVOLUTION
Flower
Seed
Pollen
SeedPlants
Div. Anthophyta – flowering plants
Charachteristics
- ~250,000+ species
- Reproductive organs in flowers
- Sporophyte dominant
- Heterosporous
2 sizes of gametes
- Microgametophyte = pollen!
- Megagametophyte:
Highly reduced: only 8 nuclei
- Triploid (3 copies of haploid chromosomes) - 3n - endosperm – new invention
Flower structure
Let’s Draw:
4 whorls of modified leaves
Flower is basically a shoot that is a stem, with leaves
Leaves = modified, don’t think of them as leaves
Contains a whorl = a collection of structures that come from the same point on a stem
starting by the outside:
1. whorl 1 – the sepal
most outter whorl – outer part of the flower
all the sepals together = the calyx
2. whorl 2 - Petals
often colorful and produce odors
All petals together = corolla
3. whorl 3 - Male tissue: stamens
produces microspores that develop into pollen grains (male gametophyte)
Each stemen has 2 major parts
1- The anther
Where meiosis occurs
Each blob is a sporangium (microsporangium)
Meiosis occurs in each one to create spores (microspores)
= become pollen grains
2- The filament
The stalk on which the anther sits
All the male tissue, so all the stamen together = androecium (house of male)
4. Whorl 4 - female tissue: carpel
Flowers can have 1 or multiple carpels
Each has 3 parts:
1- Stigma
pollen is received at this area and grows down to the style:
2- Style
Leads from the stigma to the ovary
3- Ovary
Contains the ovules (one or more)
becomes a seed when fertilized
contains the fruit (technical term – seed becomes the fruit)
female tissues all together = gynoecium (house of woman)
Flower structure - picture
