Characteristics of Invertebrates Feeding mechanisms. Excretion and Osmoregulation. Circulation and...
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Transcript of Characteristics of Invertebrates Feeding mechanisms. Excretion and Osmoregulation. Circulation and...
Characteristics of Invertebrates
• Feeding mechanisms.• Excretion and Osmoregulation.• Circulation and Gas Exchange.• Nervous System.
Feeding mechanisms.(Protozoa and Metazoa)
• Heterotrophic: ingest organic material.
I. Intracellular digestion-within a
cell: Endocytosis (phagocytosis
and pinocytosis)
Feeding mechanisms.(Protozoa and Metazoa)
• Heterotrophic: ingest organic material.
I. Intracellular digestion-within a
cell: Endocytosis (phagocytosis
and pinocytosis)
II. Extracorporeal digestion-outside
the body.
Feeding mechanisms.(Protozoa and Metazoa)
• Heterotrophic: ingest organic material.
I. Intracellular digestion-within a
cell: Endocytosis (phagocytosis
and pinocytosis)
II. Extracorporeal digestion-outside
the body.
III. Extracellular digestion-in a gut.
Excretion and Osmoregulation.
• Excretion is the elimination from the body of metabolic waste.
• Osmoregulation is the regulation of water and ion balance within the body fluids.
Excretion and Osmoregulation.
• Excretion is the elimination from the body of metabolic waste.
• Osmoregulation is the regulation of water and ion balance within the body fluids.
• Both vary depending on environment of invertebrates.
Nitrogenous Wastes and Water Conservation (Figure 3.21 A)
H2O H2O
Salt
Salt
Marine (isotonic environment): Organism is isotonic and waste is released as ammonia.
Fresh water (hypotonic environment): Organism is hypertonic and waste is released as ammonia.
Nitrogenous Wastes and Water Conservation (Figure 3.21 B)
H2O
Salt
Nitrogenous Wastes and Water Conservation (Figure 3.21 C)
H2O
Salt (in solution)
Terrestrial (“dry environment): Organisms is hypotonic and waste is released as uric acid.
Excretory and Osmoregulatory Structures
Related to surface-to-volume ratio, and animals bauplan.
1. Contractile vacuoles and water expulsion
vesicles (WEV).
Excretory and Osmoregulatory Structures
Related to surface-to-volume ratio, and animals bauplan.
1. Contractile vacuoles and water expulsion
vesicles (WEV).
2. Nephridia (Protonephridia and
Metanephridia).
Circulation and Gas Exchange
• The transport of materials from one place to another depends on the movement and diffusion of substances in body fluids.
The Big Picture
The size and bauplan of invertebrates determines the type of excretory, osmoregulatory, circulatory, gas exchange, and nervous system.
The diversity comes from the constraints placed on the particulate invertebrate group due to its bauplan.