48 Questions
What is the primary factor that determines an animal's body plan?
Pattern of development programmed by the genome
What property of water significantly affects the shape of fast swimming animals?
Its high density
What is the term for the shape of animals that are tapered on both ends?
Fusiform
Which of the following is an example of a physical law that constrains evolution?
Drag caused by water's viscosity
What is the result of millions of years of evolution?
The creation of a body plan
What is a common characteristic of fast swimming animals?
They all have a streamlined shape
What is a key reason why larger animals require thicker skeletons?
To maintain adequate support
What is the estimated running speed of the Tyrannosaurus rex?
30 km/hr
What is the primary means of exchange between an animal and its environment?
Diffusion across the plasma membrane
What is a limitation imposed on animal body plans due to physical laws?
Maximum size
What is the primary factor that limits mobility in larger animals?
Muscle mass
What is an example of convergent evolution mentioned in the text?
Streamlined shapes in swimming animals
What is the primary reason why multicellular organisms require a suitable aqueous environment?
To facilitate exchange of materials with the environment
What is the characteristic of the body plan of a pond-dwelling hydra?
It has a body wall only two cell layers thick
What is the advantage of a flat body shape in certain animals?
It increases the surface area for exchange with the environment
Why is it necessary for every cell in a multicellular organism to have access to a suitable aqueous environment?
To facilitate exchange of materials with the environment
What is a characteristic of the body plan of a parasitic tapeworm?
It has an elongated flat body shape
What is the primary factor that determines the rate of exchange in a cell?
The surface area of the cell membrane
What is the primary reason for the evolution of specialized exchange surfaces in animals?
To enable sufficient exchange with the environment
What is the effect of increasing the number of cells in a multicellular organism?
It decreases the ratio of outer surface area to total volume
What is the function of internal body fluids in animals?
To link exchange surfaces to body cells
Why do larger animals require more extensive exchange surfaces?
Because they have a smaller surface area to volume ratio
What is the advantage of branched or folded exchange surfaces?
They increase the surface area for exchange
What is the effect of the body plan of a flat, thin shape in certain animals?
It places most cells in direct contact with the environment
What is the primary function of interstitial fluid in complex body plans?
To facilitate exchange of nutrients and wastes between cells and the circulatory fluid
What is the benefit of having an external skeleton in complex body plans?
To protect against predators
What is the organizational level above organs in complex body plans?
Organ systems
What is the function of specialized filtration systems in complex body plans?
To adjust the composition of internal fluid
Why are complex body plans advantageous for animals living on land?
Because it enables the maintenance of a stable internal environment
What is the organizational level below organs in complex body plans?
Tissues
What is a benefit of having specialized cell types in the stomach lining?
Production of digestive juices and mucus
What is a characteristic shared by all four main types of animal tissues?
Similar structure and function
What is the organizational level below organs in complex body plans?
Tissues
What is the pancreas an example of in terms of organ systems?
A single organ with multiple functions
What is the primary role of the stomach in the digestive system?
Initiation of protein breakdown
What is a characteristic of the specialized organs in animal bodies?
They have specific roles in the body
Which system is responsible for body defense?
Immune and lymphatic
What is the primary function of the excretory system?
Disposal of metabolic wastes and regulation of osmotic balance of blood
Which system is responsible for gas exchange?
Respiratory
What is the function of the skeletal system?
Body support, protection of internal organs, and movement
Which system is responsible for internal distribution of materials?
Circulatory
What is the function of the endocrine system?
Coordination of body activities
What is the primary function of the circulatory system?
Internal distribution of materials
Which system is responsible for the coordination of body activities such as digestion and metabolism?
Endocrine system
What is the primary function of the integumentary system?
Protection against mechanical injury, infection, dehydration
Which system is responsible for the uptake of oxygen and disposal of carbon dioxide?
Respiratory system
What is the primary function of the skeletal system?
Body support, protection of internal organs, movement
Which system is responsible for the production of gametes and promotion of fertilization?
Reproductive system
Study Notes
Evolution of Animal Size and Shape
- Animal body plans have arisen through evolution, with physical laws (e.g., strength, diffusion, movement, heat exchange) constraining the possible forms
- Fast swimmers (e.g., tuna, sharks, penguins, dolphins, seals) have evolved streamlined, fusiform shapes to reduce drag
- Physical laws also influence animal body plans with regard to maximum size, as larger bodies require thicker skeletons and more massive muscles for locomotion
Exchange with the Environment
- Animals must exchange nutrients, waste products, and gases with their environment, which imposes limitations on body plans
- Exchange occurs through the plasma membrane of each cell, with the rate of exchange proportional to the membrane surface area involved
- Multicellular organisms require a suitable aqueous environment, either internally or externally, to enable exchange
Body Plans and Internal Organization
- Cells form a working animal body through emergent properties, which arise from successive levels of structural and functional organization
- Cells are organized into tissues, which are grouped into organs that work together to form organ systems
- Organ systems include specialized organs made up of specialized tissues and cells, with examples including the digestive system, circulatory system, and nervous system
Types of Animal Tissues
- There are four main types of animal tissues: epithelial, connective, muscle, and nervous
- Epithelial tissues protect the body, absorb and transport substances, and detect sensations
- Connective tissues provide support, connect, and transport materials, and include bone, cartilage, and fat
- Muscle tissues contract to produce movement, and include skeletal, smooth, and cardiac muscle
- Nervous tissues detect, integrate, and respond to stimuli, and include the brain, spinal cord, and nerves
Learn about the correlation between animal form and function at different levels of organization. Understand how size and shape affect animal-environment interactions and how body plans are shaped by evolution.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
