Botany Unit Notes

1
Botany Unit Notes

• Part II

2
Seed Producing Plants

• Plants require water to photosynthesize sugars
  and make food
• Many plants even need water for reproduction!
• The evolution of seed plants did away with the
  need for water in reproduction
• This was one reason leading to the success of
  seed plants on Earth

3
Seed Producing Plants

• Seed plants form male and female gametes
• Sperm are the male gametes and they are in the
  form of pollen
• The female gamete is an egg
• Pollination is when a pollen grain fuses with the
  egg cell of the female plant/organ

4
Advantages for Seeds

• Seeds nourish and protect plant embryos
• Under the right conditions a seed will germinate
  (next slide)
• Seeds allow plants to be dispersed other places
• Seeds can pass through the digestive system of
  most animals without being damaged

5
Seed Germination
6
Types of Seed Plants

• There are Two types of Seed Plants
• Gymnosperms are seed plants that do not produce
  fruits
• Most have cones as reproductive organs like pine
  trees and cycads
• Gymnosperm means naked seed
• Angiosperms are the flowering plants that do
  produce fruits and have flowers as reproductive
  organs
• enclosed seed

7
Gymnosperms

• Gymnosperms make up 3 distinct groups
• Gnetophytes phylum Gnetophyta makes up about 70
  species today and are considered living fossils
• Cycads phylum Cycadophyta are palm-like plants
  that reproduce using large cones and appeared
  around 225 mya!
• Conifers phylum Coniferophyta are the
  traditional pine trees making up the majority
  of Gymnosperms with 500 species

8
Conifer Life Cycle
9
Angiosperms

• Angiosperms are also called flowering plants
• They have flowers as their reproductive organs
• Angiosperms produce many different kinds of
  fruits
• Fruits are considered the wall of tissue
  surrounding the seed
• Fruits come in many forms like an apple or a
  dandelion

10
Angiosperms

• Angiosperms owe their success to their ability to
  attract pollinators and seed dispersers
• Animals that eat the fruits can pass the seed
  through their digestive tracts and deposit the
  seed far away from the original plant!

11
The Flower

• Flowers have male and female organs
• Ovule egg
• Pollen sperm
• Pollen stick to the top of the stigma and
  travel down the style to the ovary (pollination)

12
Angiosperm Life Cycle
13
Angiosperm Diversity

• Angiosperms are the most diverse plant group on
  the planet with over 230,000 species!
• We can categorize Angiosperms based on three
  traits
• Monocots Dicots (aka. Eudicots)
• Woody Herbaceous
• Annuals, Biennials, and Perennials

14
Monocot vs. Dicot
15
Monocot vs. Dicot

• Monocots have fibrous roots while
• Dicots have taproots

16
Woody vs. Herbaceous

• A plants stem is an identifying characteristic
• It can be herbaceous when it is soft and easily
  cut with sheers
• It can also be woody and be rough to the touch
  like the bark of a tree

17
Plant Lifespan

• Plants can live anywhere from one year to several
  years
• Annuals are plants that mature from seeds,
  produce flowers fruit, and die all in one year
• Biennials are plants that take two years to
  complete their life cycle storing some of their
  nutrients in underground rhizomes at the end of
  the first year
• Perennials are any flowering plants that live
  for more than two years