The Structure and Function in Living Things

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The Structure and Function in Living Things
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Chapter Fifteen The Diversity of Life

• 15.1 Taxonomy and Systematics
• 15.2 Algae and Fungi

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Investigation 15B
Bread Mold

• What is mold and how does it grow on bread?

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15.2 Evolution of sexual reproduction

• The first prokaryotic cells appeared about 3
  billion years ago.
• Prokaryotic cells reproduce asexually by
  splitting in two.
• Asexual reproduction does not allow for genetic
  variation unless a mutation occurs.

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15.2 Evolution of sexual reproduction

• About 1 billion years ago, the first eukaryotic
  cells appeared.
• Eukaryotic cells evolved the ability to reproduce
  sexually.
• Organisms that reproduce sexually produce more
  genetic variation among their offspring.

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15.2 Evolution of sexual reproduction

• Sexual reproduction increases genetic variation
  and leads to new species.

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15.2 Protista

• The Kingdom Protista, often called protists,
  contains many groups that evolved separately.
• Scientists categorize the many groups under three
  main types.

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15.2 Algae

• Algae are photosynthetic protists that are
  plant-like in many ways.
• Kelp is a good example of multicellular algae.

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15.2 Algae

• Some multicellular algae, such as Ulva, follow a
  pattern of reproduction called alternation of
  generations.

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15.2 Fungi

• Originally classified as plants, fungi (singular
  fungus) do not make their own food.
• Yeast, mushrooms, molds, and are examples of
  organisms in the Kingdom Fungi.

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15.2 Fungi

• Fungi do not eat their food as animals do.
• Instead, they release digestive enzymes into
  their surroundings.
• The enzymes break down organic material and the
  fungi absorb the nutrients directly into their
  cells.

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15.2 Fungi

• Some fungi live in symbiotic relationships with
  algae, bacteria, or plants.
• In those relationships, both the fungi and the
  other organism benefit.

Lichens are made of two organismsa fungus, and a
green algae or cyanobacteria.
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15.2 Fungi

• All fungi are made up of thread-like filaments
  called hyphae.
• The cells that make up the hyphae sometimes
  contain two, three, or even more nuclei.
• The hyphae form a cottony mass of threads called
  a mycelium.

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Ecology Connection
Likeable Lichens

• Lichens are important indicators of a healthy
  ecosystem.
• Many lichens are sensitive to chemical pollutants.

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Activity
How to Make a Simple Cladogram

• In this activity, you will use fruit to learn how
  to make a simple cladogram.