Animal Lesson 1 Flashcards
5 core concepts of biology as they relate to animal development and physiology?
- Structure & Function
- Evolution
- System
- Information flow
- Transformation of energy and matter
Structure & Function
Each thing has a specific function. The shape and makeup of biological structures.
Evolution
How these structures appear in animals to pass the genes on to the next generation.
Systems
All structures need to be interconnected in animals bodies.
Information Flow
Can be chemical or electrical. The systems need to communicate with each other somehow.
Transformations of energy and matter
Need energy to function and transfer the energy so we can see it.
What is an animal?
- Multicellular
- Heterotrophic
- Lack cell walls
- Capable of movement at some stage of development
- Possess regulatory genes called Hox Genes
Heterotrophic
Obtains energy and nutrients from other organisms.
Hox genes
They are involved in development. They make the body part. The order they are set up corresponds to the different parts of the body in which they code proteins for.
What are the functions animals need to carry out?
- Reproduction and development.
- Obtain matter and energy and transport it throughout the body.
- Gas exchange between internal and external environments (need O2 for cellular respiration and get rid of CO2).
- Protection from external environment, pathogens. ie. Heat, cold, viruses, bacteria.
- Maintenance of water and solute concentrations in the internal environment.
- Support and movement of the body.
- Coordination of body functions (so we don’t have to think about breathing).
Hierarchical organization of structures
- Molecules
- Organelles (ie. nucleus)
- Cells (ie. cheek cells)
- Tissues
- Organs (ie. heart)
- Organ Systems (ie. digestive system)
- Organisms (ie. dog)
Main molecules
Lipids, Carbs, proteins, nucleic acids.
Tissues
Similar cells held together in some form of matrix (membrane or fibres).
Tissue types
- Epithelial tissue. Line gut, mouth, etc.
- Muscle tissue (ie. cardiac and nervous tissues).
- Connective tissue. A combo of cells and fibres that keeps structure together. (ie. bone and blood).
How is structure related to function?
Structure enables function. Structure constrains function.
Structure enables function
A structure’s physical and chemical characteristics
influence its interactions with other structures, and
therefore its function.
Structure constrains function
Functional-trade offs. Specialization for one
function may limit a structure’s ability to perform
another function. It is impossible to optimize
for all parameters (the structure can’t do everything). Through evolution certain features favour one direction, and same in the other.
Functional trade-off example
Cartilage has high flexible and low strength, while bone is low flexible and high strength. Both are connective tissue. ie. If you have a boney body, you’re heavier/stronger but not as flexible. So many fins other structures to do other thinned like float in water.
What membrane would function best in allowing molecules to move between two compartments?
A layer with fewer membranes to travel through and with less space. Narrower and flat is better.
How is evolution related to function of structures?
It’s where function can have an impact on structure. Structure to Function to Fitness through evolutionary pressure, then back to structure. Through natural selection organisms become adapted to their
environment. A better functioning structure for environment might be passes on to the next generation.
Example of Grey Seal
Structures make sense in the context of the animal’s
environment. On land the seal looks like it can’t move very well, but it moves very well in water.
Sponges
Are animals, and have their own version of hox genes that are a bit different.
Biological structures interact to form complex systems?
A change in one component of a network can affect
many other components.
Example of knee injury
Cells: Changes at the molecular and cellular level trigger.
Tissues: Degradation of cartilage to repare it.
Organ: Knee
Organ systems: Musculoskeletal system must compensate.
Organism: Locomotion is compromised. ie. limp.
Emergent properties
Each level of organization has properties not exhibited by lower levels. Emerge into something new. Combine them and it levels up.
Emergent properties example
E.g., Structure → emergent property
– Cardiac muscle (tissue) → contracts
– Cardiac muscle + other tissues = heart (organ) → coordinated pumps
– Heart + vessels + blood = circulatory system
→delivers O2 around the body
i.e., muscle alone cannot pump heart; heart
alone cannot deliver O2
What represents a structure to emergent pairing
Cell to life, because it’s the basis of life on its own.
All cells must exchange material with what?
The external environment. Materials go in and out.
How do simple structures exchange materials with the environment?
Some animals are structurally simple enough that all cells are in direct contact with the external
environment.
Hydra example
Hydra: two layers of cells and both exchange materials with the outside layer. One layer exchange with the outside, the other exchange with the gastrovascular cavity filled with fluid.
More complicated bodies require organ systems that what?
− can exchange material with the external environment.
− can transport material around the body.
What systems exchange with external
environment?
Digestive system
Excretory system
Respiratory system
Integumentary system
What systems transport of material
within the body?
Circulatory system
Why does the lining of the small intestine have a lot of surface area?
To be able to absorb nutrients.
Excretory system
Includes the kidneys and bladder. Cleaning of blood and waste material.
Lung tissue
Very thin layer of tissue for the gases to pass through
The body systems are what?
All connected to environments. The circulatory system brings all these features around the body.
Interstital fluid
Help facilitate exchange of nutrients in gases. In organs and between them.
Why are bodies wet?
Because membranes are wet because of the interstitial fluid.
All perception and response requires what?
Informational flow.
Chemical (hormones) and/or electrical signaling (through nervous system)?
Between cells coordinates responses at the cellular, tissue, organ, and system levels.
Endocrine and nervous systems are the major
systems that what?
Control responses to stimuli and coordinate body activities. Info flow
Homeostasis
The maintenance of a relatively stable internal environment, regardless of the response that’s happening externally. Have large external fluctuations, but small internal fluctuations.
Why is a stable environment important?
Cells have conditions under which they function optimally. ie. Enzymes and membranes are sensitive to changes in their surroundings.
Homeostasis relies on what?
The negative feedback loop to maintain set point.
Negative feedback
Control mechanism in which the response opposes the original stimulus.
Positive feedback
Control mechanism in which the response reinforces the original stimulus.
Temperature example
Set point: Room temp at 20.
Stimulus: room temp increases.
Sensor/control center: thermostat turn heater off.
Response: heating stops.
Then room temp decreases and back to set point.
Set point: Room temp at 20.
Stimulus: Room temperature decreases.
Sensor/control center: thermostat turns heater on.
Response: heating starts.
Then the room temp increases then back to set point.
Examples of negative feedback?
Our bodies sweat to cool down when we are hot. An excessively high concentration of a molecule
inhibits its production. High blood CO2 triggers more rapid breathing.
Examples of positive feedback
Giving birth and breastfeeding.
Regulated changes in physiological
parameter set points (and their normal
ranges) are essential to what?
Normal body functions
Examples of regulated changes
- Stage of life
– E.g., Puberty - Cyclic
– E.g., Menstrual cycles, Circadian rhythm - Response to environmental change
– E.g., Acclimatization
All physiological functions require what?
Energy
What does food do to the body?
how animals obtain:
– chemical energy (e.g., sugars, fats, proteins; energy stored within bonds). They break bonds and release chemical energy.
– and molecular building blocks (e.g., amino acids). To build a different structure in your body.
Stored chemicals energy is converted to what?
ATP. It will function everywhere in your body. They need to store food once on the body.
– Also stores energy within bonds (aka chemical energy).
– Needed to carry out the cellular work necessary for
physiological activities.
Natural selection favours the evolution of
efficient use what?
Resources (food and energy), within constraints.
Organisms have limited energy and material
resources. Requires efficient allocation across competing functional demands.
Resources Trade off
Put resources towards one part of the body but not the other parts of body to pass on genes.
E.g., Reduced capacity for wound healing when
producing eggs in ornate tree lizard. Reproductive function often takes precedence.
E.g., Wait to digest food when oxygen is not limited. Because digestive systems need oxygen in to power up the cells needed. In grey seal.
Function trades-off example
The ability of skin to protect is limited by its
need to exchange materials.
Life history trade-off example
Animals that produce many offspring at once
provide little care for those offspring.
Resource/ energetic trade-off example
Overtraining in elite female athletes can cause
them to cease menstruating.
