“Alive”
All Living Organisms share 5 fundamental characteristics
- Cells
- Replication/Reproduction
- Information (Genes)
- Energy
- Evolution
Land Plants (Chap. 28.1)
Why do Biologists study plants?
1. Plants provide Ecosystem services
- Produce Oxygen (a byproduct of photosynthesis)
- Build soil
- Hold soil - nutrients, and H2O - water
- Moderate the climate - Provide shade, wind block
2. Plants are primary producers
- They convert energy from sunlight into chemical bond energy (sugars)
- This supports virtually all other organisms in terrestrial habitats
3. Plants provide humans with food, fuel, fiber, Building materials, and medicines
How do Biologists study Land Plants?
- To understand diversification, they:
1. Compare morphological traits
2. Analyze the fossil record
3. Build phylogenetic trees
Comparing Morphological Traits:
A. Nonvascular plants - lack vascular tissue (dedicated cells that only conduct water
or dissolved nutrients within the plant) (E.g. Mosses-representative group)
a. Mosses still need water for reproduction because the sperm still needs to
swim to the egg, and need drops or splashes of water for the sperm to
swim
b. Mosses can not grow very tall due to lack of vascular tissue - so their cells
have to move things to next to them
c. Mosses: Gametophyte (n) is the larger life stage that we see- only lineage
like this.
d. Mosses were the first plants to evolve - these 3 traits vital for living on
land
e. Cuticle is a waxy layer that prevents water loss from stem and leaves
f. Pores open and close via the Stomata to allow gas exchange.
g. These are now found in almost all plants
, B. Seedless vascular plants have well-developed vascular tissue but do not make
seeds (E.g Ferns- representative group)
a. Vascular tissue make of xylem (carries water) and phloem (carries
nutrients)
b. Still need water for reproduction so sperm can swim to the egg
c. Do not produce seeds
d. From here forward, Sporophyte (2n) is the larger life stage we see
e. Ferns have cuticle, pores, and stomata
f. Ferns are the first plants we see with these further adaptations for living
on land:
i. Vascular tissue
ii. Roots
iii. True leaves - allow for more control within the environment
iv. Tracheid cells for water transport
C. Seed Plants have vascular tissue and make seeds
a. Gymnosperms produce “naked” seeds that do not develop in an enclosed
structure (E.g. Ginkgo, confers) Are vascular and make seeds but are
flowerless (1st seed-bearing plants)
i. Ginkgo - most people want the male trees due to the bad smell ;
Cycads are called “Sago palms” here, but not really palms
ii. Ginkgo, Cycads, Pines:
1. 1st lineage to make pollen (we see a lot of yellow powder
coating everything in the spring - pine pollen is large)
2. Pollen innovation makes them independent of water
reproduction
3. Poll protects, holds, and carries the sperm - water is not
needed to carry sperm and are not stuck around water
areas and can colonize other areas
4. Gymnosperms are the first plants we see with further
adaptations for living on land:
a. Wood - comes from dead old vascular tissue
b. Pollen
c. Seeds
b. Angiosperms - (E.g: All flowering plants); “Encased” seeds develop inside
a protective structure (fruit) Are vascular and make seeds, flowers, and
fruits
i. 90% of all plants
ii. Angiosperms have all the innovations of earlier lineages of land
plants, and their own innovations:
1. Flower- specialized reproductive shoot
All Living Organisms share 5 fundamental characteristics
- Cells
- Replication/Reproduction
- Information (Genes)
- Energy
- Evolution
Land Plants (Chap. 28.1)
Why do Biologists study plants?
1. Plants provide Ecosystem services
- Produce Oxygen (a byproduct of photosynthesis)
- Build soil
- Hold soil - nutrients, and H2O - water
- Moderate the climate - Provide shade, wind block
2. Plants are primary producers
- They convert energy from sunlight into chemical bond energy (sugars)
- This supports virtually all other organisms in terrestrial habitats
3. Plants provide humans with food, fuel, fiber, Building materials, and medicines
How do Biologists study Land Plants?
- To understand diversification, they:
1. Compare morphological traits
2. Analyze the fossil record
3. Build phylogenetic trees
Comparing Morphological Traits:
A. Nonvascular plants - lack vascular tissue (dedicated cells that only conduct water
or dissolved nutrients within the plant) (E.g. Mosses-representative group)
a. Mosses still need water for reproduction because the sperm still needs to
swim to the egg, and need drops or splashes of water for the sperm to
swim
b. Mosses can not grow very tall due to lack of vascular tissue - so their cells
have to move things to next to them
c. Mosses: Gametophyte (n) is the larger life stage that we see- only lineage
like this.
d. Mosses were the first plants to evolve - these 3 traits vital for living on
land
e. Cuticle is a waxy layer that prevents water loss from stem and leaves
f. Pores open and close via the Stomata to allow gas exchange.
g. These are now found in almost all plants
, B. Seedless vascular plants have well-developed vascular tissue but do not make
seeds (E.g Ferns- representative group)
a. Vascular tissue make of xylem (carries water) and phloem (carries
nutrients)
b. Still need water for reproduction so sperm can swim to the egg
c. Do not produce seeds
d. From here forward, Sporophyte (2n) is the larger life stage we see
e. Ferns have cuticle, pores, and stomata
f. Ferns are the first plants we see with these further adaptations for living
on land:
i. Vascular tissue
ii. Roots
iii. True leaves - allow for more control within the environment
iv. Tracheid cells for water transport
C. Seed Plants have vascular tissue and make seeds
a. Gymnosperms produce “naked” seeds that do not develop in an enclosed
structure (E.g. Ginkgo, confers) Are vascular and make seeds but are
flowerless (1st seed-bearing plants)
i. Ginkgo - most people want the male trees due to the bad smell ;
Cycads are called “Sago palms” here, but not really palms
ii. Ginkgo, Cycads, Pines:
1. 1st lineage to make pollen (we see a lot of yellow powder
coating everything in the spring - pine pollen is large)
2. Pollen innovation makes them independent of water
reproduction
3. Poll protects, holds, and carries the sperm - water is not
needed to carry sperm and are not stuck around water
areas and can colonize other areas
4. Gymnosperms are the first plants we see with further
adaptations for living on land:
a. Wood - comes from dead old vascular tissue
b. Pollen
c. Seeds
b. Angiosperms - (E.g: All flowering plants); “Encased” seeds develop inside
a protective structure (fruit) Are vascular and make seeds, flowers, and
fruits
i. 90% of all plants
ii. Angiosperms have all the innovations of earlier lineages of land
plants, and their own innovations:
1. Flower- specialized reproductive shoot
