Transcript Bioenergetics

Circulatory Systems Move
Nutrients, Gases and Other Materials
• Two basic types:
– Open system:
• Blood periodically leaves the blood vessels, bathes
the tissues, and is recollected into the vessels.
• Found in arthropods
– Closed system:
• Blood never leaves the blood vessels
• Found in humans and other animals
Circulatory Systems Move
Nutrients, Gases and Other Materials
• Circulatory systems have three main
components:
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–
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Vessels
Blood
Hearts
Each evolved from rather simple components in
primitive worms to highly complex ones found
in chordates.
Animals Must Maintain Proper
Water Balance
• For all cells, water is a precious necessity.
• It is necessary to maintain the appropriate
concentrations of solutes in an organism’s
body
– Solute concentrations can be different from
those found in body compared to the
environment.
– Need to have an ability to regulate the solute
concentrations due to these differences.
Animals Must Maintain Proper
Water Balance
• Fish living in
hypertonic
environment:
– Drinks water.
– Loses water through
the gills.
– Loses solutes in urine
and active transport
through the gills.
Animals Must Maintain Proper
Water Balance
• Fish living in
hypotonic
environment:
– Drinks no water.
– Water absorbed by
osmosis through gills
and body surfaces.
– Solutes absorbed by
active transport at gills.
Animals Must Maintain Proper
Water Balance
• Terrestrial animals have 5 ways to reduce
water loss:
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–
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Live in moist environment
Live in habitat with high humidity
Be active at night when humidity is the highest
Special body coverings to prevent water loss.
Animals Must Maintain Proper
Water Balance
• Terrestrial animals
have 5 ways to reduce
water loss:
– Organisms living in the
desert have special
mechanisms for
reducing water loss in
feces and concentrating
wastes in urine
Organisms Must Get Rid of
Metabolic Wastes
• Cellular metabolism produces waste
compounds that must be disposed of.
– Example: Ammonia
• Animals evolved a number of different
excretory systems
– Blind tubes that collect waste to more complex
organs such as kidneys.
How Do Organisms Move?
• External environments are
challenging.
• Four options for dealing
with challenges:
– Isolate themselves
– Seek shelter
– Adjust to changing
conditions
– Move to more favorable
environments
Microbe Movement
• Thick cell walls and shells protect many microbes
from potentially hostile environments.
• Microbes can move using flagella, cilia, and
pseudopodia (false feet)
Animal Movement
• Involves the
interactions between
muscles and their
shells or skeletons
• Among animals, there
exist 3 types of
skeletons:
– Hydrostatic
– Exoskeleton
– Endoskeletons
How Do Organism Reproduce?
• Purpose of life is to reproduce
– Because life can only persist through
reproduction
• Two types
– Asexual
• Binary fission or mitosis
– Sexual
Most Common Form of
Reproduction is Asexual
• Process of one cell becoming two
– Binary fission occurs in prokaryotic cells
– Mitosis occurs in all others
• Also allows for tissue repair
Asexual Reproduction
Sexual Reproduction Evolved
Among Bacteria, Protists and Fungi
• Conjugation
– Cytoplasmic bridge
(pilus) develops
between two
individuals allowing
one-way exchange of
genetic material.
Sexual Reproduction Among
Eukaryotes
• Follows three general types:
– Diploid cycle:
• Seen in all animals and some protists.
• All cells of the organism are diploid except for
gametes.
• Gametes remain single-celled, haploid entities until
fertilization.
Sexual Reproduction Among
Eukaryotes
• Follows three general types:
– Haploid cycle:
• Seen in all fungi and some algae.
• All cells of the organism are haploid.
• Budding and other types of asexual reproduction
produce haploid individuals.
• When reproduce sexually, cells merge, fuse nuclei, and
become diploid.
– Immediately undergo meiosis producing haploid spores
Sexual Reproduction Among
Eukaryotes
• Follows three general types:
– Alternating cycle:
• Seen in all plants and some algae
• Has two distinct generations
– Haploid gametophyte that produces
gametes.
– Diploid sporophyte that produce spores.
Sexual Reproduction in Water is
Relatively Easy
• Aquatic organisms
spew gametes into
the environment
• Gametes must find
each other so
fertilization can
occur
• Timing of gamete
release is important
Sexual Reproduction in Water is
Relatively Easy
• Simultaneous release of gametes is
important. Two reasons:
– Facilitates fertilization.
– Foils predators by “flooding the
market”.
Sexual Reproduction in Water is
Relatively Easy
• Less danger of
gametes drying out.
• Less protected.
• Eggs have less yolk
than those that
reproduce on land.
Many Animals Successfully
Reproduce on Land
• The ability to reproduce on land apparently
evolved independently among segmented
worms, mollusks, arthropods and chordates.
• Each group originated in the ocean and
evolved successfully in different
environments until they became terrestrial
organisms.
Many Animals Successfully Reproduce
on Land
• Transition from water to land is seen most
dramatically by comparing their eggs.
• Marine fish have little yolk and no shells.
• Eggs of freshwater fish amphibians, which
reproduce in nutrient-poor environments, have
considerable more yolk and are surrounded by
slime layers.
Many Animals Successfully
Reproduce on Land
• Eggs of reptiles, birds,
and primitive
mammals are the
largest known, contain
relatively huge
amounts of yolks.
Many Animals Successfully
Reproduce on Land
• The eggs of advanced
mammals have no
shells and no yolk.
• Offspring are retained
within the female’s
body (marsupials)
where they are
protected and
nourished.
After Fertilization, Organisms
Develop and Grow
• Pattern of embryonic
development has three
general phases.
• First phase: fertilized
egg undergoes mitosis
which increases the
number of cells little
or no overall growth in
size.
After Fertilization, Organisms
Develop and Grow
• Second phase:
– Involves the early appearance of organ system.
• Third phase:
– Further refinement of organ systems and
significant growth.
Animal Development
Two patterns of post-hatching and
development in birds
• 1. Hatchlings are
virtually helpless and
totally dependent on
parents for food and
protection.
• 2. Hatchlings can find
their own food and
partially protected
from the environment
by downy feathers.
Mammals Development
• Mammals are helpless at birth and totally
dependent on adults for nourishment and
protection
– Initial nourishment provided by mammary glands.
– Following weaning, young are still dependent on
adults for food.
– Need to learn where to seek food and shelter, how
to avoid predators from associations from parents
and adults.