Zoology : Introduction to Animals (Ch.27)

1
Zoology Introduction to Animals (Ch.27)

• Zoology is the study of animals. This includes
  the study of the following characteristics of
  animals
• Structure/function
• Classification
• Lifestyle

2
General Features of Animals

• Animals exhibit the following features
• Heterotrophy Tissues
• Mobility Absence of cell wall
• Multicellularity
• Diploidy
• Sexual reproduction
• Blastula formation

3
Animal Features

• Heterotrophy animals cant make their own food,
  and must obtain their food
• Mobility animals have the ability to move
• Multicellularity animals are composed of many
  cells
• Diploidy adults have two copies of each
  chromosome

4
Animal Features

• Sexual reproduction animals reproduce sexually,
  egg cell and sperm cell
• Absence of a Cell Wall animal cells lack a cell
  wall
• Blastula formation after fertilization the
  zygote produced from the sperm and egg forms a
  hollow ball of cells (blastula)

5
Animal Cell Specialization

• Most animals reproduce sexually with an egg and a
  sperm uniting to form a zygote.
• This zygote cell then divides into solid ball of
  cells (morula) and then a hollow ball (blastula)

morula
blastula
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Animal Cell Specialization

• Cells in the morula have the ability to change
  into specialized cells for the animal. ( Hair
  cells, muscle cells, nerve cells, etc.)
• These original cells capable of being specialized
  cells are called stem cells.

7
Animal Cell Specialization

• As a result of the DNA in the cells, animals show
  a wide variety of differences.
• The development of the animal through its genetic
  code and environment shapes the animals anatomy
  and behavior.

8
Animal Embryonic Development

• Upon fertilization of an animal egg by a sperm, a
  zygote is formed. The chromosomes in the egg and
  the chromosomes in the sperm combine to form a
  diploid (2) set of chromosomes containing genes
  for the zygotes development

9
Embryonic Development

• Once a zygote is formed, it appears that genes
  found in the egg control the development of the
  zygote into a blastula.
• Studies have shown that proteins produced by
  genes from the egg determine the initial
  differentiation of cells into specialized body
  parts.

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Embryonic Development

• There are typically four stages of embryonic
  development
• Cleavage
• Patterning
• Differentiation
• Growth

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Embryonic Development

• Cleavage the process of the zygote dividing,
  dividing again, and at different rates at each
  end of the cell to produce a ball of
  approximately a thousand cells.(blastula)

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Embryonic Development

• Patterning In this stage cells organize
  themselves into layers and masses. This process
  is called gastrulation

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Embryonic Development

• During gastrulation the embryo conains different
  layers.
• Endoderm inside
• Ectoderm outside
• Mesoderm middle
• These layers will develop into specialized animal
  organs and areas

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Embryonic Development

• Differentiation the third stage of embryonic
  development includes the division of cells to
  form specialized structures such as nerve cells,
  blood cells, skin cells, etc.

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Embryonic Development

• Growth the final stage of embryo development
  results in division of specialized cells to
  produce organs, organ systems, and the animal.

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Embryonic Development

• Studies have shown that proteins built by the
  eggs genes determine the steps of development.
• In some studies it was found that the addition of
  a protein during the patterning stage will cause
  an animal to have two heads, two tails, no skin,
  etc.

2- headed tadpole as a result of protein given
blastula
Normal tadpole at same stage.
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Animal Embryonic Development

• In most all animals the four stages described are
  observed in their development.

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Sea Urchin Embryonic Development

• Picture A represents a zygote, and picture F a
  late stage blastula.

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Animations/Photos of Different Animal Embryonic
Development

• http//www.luc.edu/depts/biology/dev/devm.htm

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Animal Features

• Tissues animal cells are organized into tissues
• Example of tissues muscle tissue, skin tissue,
  nerve tissue, etc.

Human Skin tissue layers
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Body Symmetry

• Animals have a body plan or shape.
• Sponges have the simplest body plan. Sponges have
  an irregular or asymmetrical.
• Other animals have a form of symmetry to their
  bodies

Sponge asymmetrical body plan
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Body Symmetry

• Radial Symmetry some animals have body parts
  arranged around a central axis. Some aquatic
  animals show this symmetry.
• Ex) sea anemone, jellyfish, etc.

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Body Symmetry

• Bilateral symmetry a body plan of all other
  animals which show distinct right and left
  halves.
• Cephalization having nerves, brain at one end
  of the body

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Symmetry Activity

• Pair up with a classmate and in your journal do
  the quick lab on page 599 to practice the type
  of symmetry animals have.

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Internal Body Cavity

• Animals with bilateral symmetry have one of three
  basic body plans
• Acoelomate animals with no body cavity.
• Pseudocoelomate animals with a falsebody
  cavity
• Coelomate animals with a body cavity within the
  mesoderm.

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Body Segmentation

• Segmented animals have similar units called
  segments.
• Then kingdom Animalia contains about 35 major
  divisions or phyla.
• Phylogenetic tree a branching diagram to show
  animal relationships based upon the anatomy of
  living animals

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End of Section 1

• In your journal do the section 1 review. (Pg.
  603)

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Section 2 Animal Body Systems

• Animals need to perform specific functions for
  survival. The major functions they need are
• Digestion, respiration, circulation, conduction
  of nerve impulses, support, and excretion

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Digestion

• Animals need to acquire energy through food.
• Most animals digest or break down their food
  within a digestive cavity or system.
• Enzymes play an important role in the digestion
  of food.
• Simple animals have a gastrovascular cavity,
  while others have a digestive tract.

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Respiration

• Repiration is the uptake of oxygen and the
  release of carbon dioxide gas.
• Simple animals achieve this through diffusion,
  while other animals achieve this with gills, or
  lungs.

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Circulation

• Many materials must be transported to and from
  the cells of animals. Two types of circulatory
  systems achieve this
• Open circulatory system and closed circulatory
  systems.
• Open a heart pumps blood into the body cavity
• Closed heart pumps blood through blood vessels

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Conduction of Nerve Impulses

• Animals have nerve cells (neurons) which carry
  messages which allow for coordination of the
  body. (senses)
• Simple animals contain ganglia which are a
  cluster of neurons.
• Other animals have brains to coordinate all
  sensory information

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Support

• Animals achieve support by the following
• Hydrostatic skeleton consists of water under
  pressure in a cavity
• Exoskeleton rigid external skeleton
• Endoskeleton hard material bone embedded
  within an animal

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Reproductive Strategies

• Two types of reproduction Asexual and sexual
• Asexual reproduction that doesnt involve the
  fusion of two gametes.
• Sexual a new individual is formed by the union
  of gamestes.

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Reproductive Strategies

• Some animals are hermaphrodites. This means they
  have both testes and ovaries, and can produce
  both types of gametes (sperm and eggs)
• Ex. slugs, some fishes, and earthworms

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Fertilization

• Animals may have external fertilization or
  internal fertilization.
• External sperm fertilizes the egg outside of
  the body
• Internal sperm and egg union occurs within the
  females body

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Ch. 27 Assignment

• Using the internet and other resources choose 1
  animal to research. For your animal explain how
  they achieve the following six important
  functions
• Digestion, respiration, circulation, conduction
  of nerve impulses, support, excretion, and
  reproduction

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Ch. 27 Review

• In your journal answer the following questions
  found on page 612,613.
• Using Key Terms
• Understanding Key Ideas 6-12
• Critical Thinking 17

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Ch. 27 Journal Summary

• Your zoology journal should have the following in
  it
• Symmetry Activity(pg.599)
• Section review Qs (pg 603)
• Ch. 27 Activity animal functions.
• Ch. 27 Review