Animal Form and Function

Question 1

What is environmental exchange?

Answer 1

Animals must exchange nutrients, waste products and gases → further limitations on body size and shape
- Rate of exchange is proportional to surface area, while amount of material that needs to be exchanged depends on volume

Question 2

What are the approaches that animals have for environmental exchange

Answer 2

» Optimise body shape for exchange

» Develop specialised exchange surfaces and a circulatory system

Question 3

How do animals optimise their body shape for environmental exchange

Answer 3

Some animals have body shapes that allow them to put many of their cells in contact with the environment → can still rely on diffusion, Which makes it easier to have environmental exchange

Question 4

What are two examples of animals optimising their body shape for environmental exchange?

Answer 4

» eg gastrovascular cavity in hydras, jellyfish and other cnidarians
» eg flat body in planarians

Question 5

Draw the two types of gastrovascular cavity in hydras

Answer 5

in work book

Question 6

Why are there more systems in more complex animals?

Answer 6

• Complex organisims have multiple systems that have specialised surfaces which increase surface area for environmental exchange.
• These include: respiratory system, digestive system, excretory system and circulatory system

Question 7

What is the relationship between the exchange surfaces and the circulatory system?

Answer 7

• Respiratory system brings in oxygen from the environment and uses it to oxidize the blood for our organs and releases CO2 back into the environment.
• Digestive system brings in food from the environment which provides nutrients. This is absorbed by microvili and sent into the blood stream to be taken around the body.
• Excretory system takes waste products out of the blood (kidneys) and this goes back into the environment

Question 8

Draw the Exchange surfaces and circulatory system diagram.

Answer 8

in work book

Question 9

What are the benefits of a more complex body plan

Answer 9

Despite challenges of exchange, complex body plans have several advantages over simpler ones
» External skeleton protect ≠ predation
» Sensory organs provide detailed information about environment
» Internal digestive organs digest food gradually, controlling energy storage
» Maintaining body internal environment allows living in a variable external environment

Question 10

How many types of tissue are cells divided into

Answer 10

Cell are organised into 4 types of tissues

Question 11

What are the four types of tissue

Answer 11

» Epithelial: sheets of cells that cover the outside of the body and line organs and cavities inside the body
» Connective: spare cells embedded in extracellular matrix; binds and supports other tissues
• Loose or fibrous connective tissue, cartilage, bone, adipose tissue, blood
» Muscle: filaments of actin and myosin, which work together to enable contractions; responsible for nearly all types of body movement
» Nervous: receive, process and transmit information

Question 12

What are organs made up of?

Answer 12

multiple types of tissues

- eg. skin is made of fat, connective tissue, etc

Question 13

What are organ systems made up of?

Answer 13

• Groups of organs that work together to make up an organ system
• there are usually 7 organs that make up an organ system
  eg. digestive system

Question 14

What are the major organ systems?

Answer 14

There are 11 and they are based on what an animal need to do to survive
- Obtain nutrients and oxygen: Digestive, respiratory, circulatory, excretory
- Fight off infections: Integumentary, immune
- Produce offspring: Reproductive
We also have to have systems that allow us to have these systems run smoothly which are:
- Coordinate body functions: Nervous, endocrine
- Move: skeletal, muscular

Question 15

What does an animal need to be able to coordinate body functions?

Answer 15

• Tissues, organs and organ systems must work together -> need coordination

Question 16

What are the two internal communication systems?

Answer 16

• Endocrine

- Nervous

Question 17

What is the Endocrine system?

Answer 17

• Signalling molecules (hormones) are released into the blood stream and carried to all locations in the body
• Only cells that have receptors for that specific hormone respond
• Hormones remain in blood for min to hours → long lasting effect

Question 18

What is the nervous system?

Answer 18

Neurons transmit signal (nerve impulse) along dedicated routes (axons) to specific locations
» Can act on other neurons, muscle cells, cells and glands that produce
secretions
- Extremely fast communication, and effect only last a fraction of a second

Question 19

How do nerve impulses travel?

Answer 19

A Nerve impulse will travel a long distance along an axon as a change in voltage (electrical signal) and will travel a short inter-cell distance as a chemical signal (neurotransmitter)

Question 20

What is the difference between the endocrine system and the nervous system?

Answer 20

Endocrine and nervous system differ in signal type, transmission, speed and duration → which are all adapted to their different functions

Question 21

What are the effects of the Nervous and Endocrine systems?

Answer 21

• Endocrine:
  » Gradual change that affect whole body, such as growth, development, reproduction, metabolism, digestion
• Nervous:
  » Immediate and rapid responses to environment, such as reflexes and movement

Question 22

What is homeostasis?

Answer 22

To maintain a stable environment

Question 23

Why is it important to have homeostasis?

Answer 23

so that there is a stable environment is perfect for our cells to do their work

Question 24

How is Homeostasis achieved?

Answer 24

Achieved via feedback control
» Sensor
» Control center (compare to set point)
» Effector (response)

Question 25

What does it mean that animals can either be regulators or conformers?

Answer 25

An animal that is a regulator works hard to regulate its internal environment and maintain homeostasis, whereas a conformer will conform to the external environment around it

Question 26

How do animals regulate homeostasis?

Answer 26

• Homeostasis can involve a variety of processes
• Form
• Function
• Behaviour

Question 27

How do animals undergo Thermoregulation by form?

Answer 27

• Insulation (feathers, fur, blubber)
• Circulatory adaptations (eg countercurrent heat exchanger)
• Brown fat

Question 28

How do animals undergo Thermoregulation by function?

Answer 28

- Thermogenesis in endotherms
» Muscle activity (shivering)
» Increased metabolic activity
- Evaporative cooling (sweat) 
- Vasodilation (widening of blood vessels) and vasoconstriction (narrowing of blood vessels)

Question 29

How do animals undergo Thermoregulation by behaviour?

Answer 29

• Basking in the sun, or seeking out the shade in ectotherms
• Ectothermy (cold blooded animals have to be warmed by the sun) consumes much less energy than endothermy (warm blooded animals use metabolism to warm up)

Question 30

What are the energy requirements of an animal?

Answer 30

• Energy flow and transformation in an animal (“bioenergetics”)
  » Determines nutritional needs,
  » Is related to size, activity and the environment
• Remember that animals are heterotrophs
  » Harvest chemical energy harvested from food (by digestion) to produce ATP, which is then used to fuel metabolism and activity

Question 31

How do we balance our energy budget

Answer 31

Energy harvested from food needs to be invested in the different needs of the organism
» Maintenance
• Basal metabolism
• Thermoregulation
• Repair
» Activity
» Growth
» Reproduction