Animal form and function (part 1 & 2)

Question 1

Basic information about animal form and function

Answer 1

• Form and function are correlated
• Hierarchical organization
• Animals exchange materials with the environment
• Homeostasis
  e.g. Ears of jackrabbit
  Form: thin and long, Function: acute hearing and heat exchange
  e.g. evolution of form and function in aquatic animals
• Properties of water limit the possible shapes for animals that are fast swimmers
• Fast swimmers have a stream-lined, fusiform shape (an example of convergent
  evolution)

Question 2

Animal cells

Answer 2

• Basic unit of all organisms e.g. stem cells, liver cells, red blood cells, etc…

Question 3

Animal tissues

Answer 3

Epithelial
▪ Covers outside of body, lines organs and cavities
2. Connective
▪ Holds many types of tissues and organs together
3. Muscle
▪ Responsible for movement, heart contraction
4. Nervous
▪ Receives, processes, and transmits information

Question 4

Animal organs

Answer 4

• Collection of tissues that have been adapted to perform a specific function
  ▪ Organs can have distinct physiological roles and belong to more than one organ system
• Ex. Pancreas
  ▪ Produces digestive enzymes (exocrine pancreas)
  ▪ Produces hormones (endocrine pancreas)

Question 5

Coordination

Answer 5

• Example: during long dives, the harbor seal slows its heart rate, collapses its lungs, and lowers its body temperature while swimming
• Example: during exercise, a human increases sweat rate, heart rate, blood pressure, airway diameter, decreases digestion, etc…
• Much of this coordination depends on two systems: the ENDOCRINE system and the NERVOUS system

Question 6

Exchange

Answer 6

• Materials such as nutrients, waste products,
  and gases must be exchanged across the cell membranes of animal cells
• The rate of exchange is proportional to a cell’s SURFACE AREA

Question 7

Homeostasis

Answer 7

• Homeostasis: same; standing still = maintaining internal stability
  ▪ Faced with environmental fluctuations, animals manage their internal environment by regulating or conforming
  ▪ Regulators: maintain a constant internal environment
  ▪ Conformers: allow internal conditions to vary with external ones
  *Large fluctuations in the external environment induce equally large responses of the control system to offset the disturbance

Question 8

Draw the two graphs showing conformers and regulators

Answer 8

DRAW

Question 9

More on homeostasis

Answer 9

• Made usually of negative feedback loops
  Removes or opposes signal
  e.g. Negative: blood sugar regulation
  High: Insulin is released which signals the uptake of sugar into the liver, muscles and adipose tissues = decreased blood sugar
  Low: Glucagon is released which signals the breakdown of glycogen into glucose = increased blood sugar
  e.g. Positive: Birth
• Baby pushes on cervix - cervix stretches - oxytocin is released - oxy. contracts uterus - fetus moves down and pushes on cervix - cervix stretches…

Question 10

Osmoregulation

Answer 10

• Large fluctuations in the external environment induce equally large
  responses of the control system to offset the disturbance
• Net movement (diffusion) of water across a semipermeable membrane from a region of low solute concentration to a region of high solute concentration…. Water diffuses until the solute concentration is EQUALIZED
• Osmolarity: total concentration of all the solutes in a solution
  Isosmotic: Same osmolarity (normal cell)
  Hyperosmotic: Higher osmolarity (lysis - cell bursts)
  Hypoosmotic: Lower osmolarity (crenation - cell looks deflated)

Question 11

Freshwater

Answer 11

• Osmoregulators
• Hyperosmotic
  Water: gains, Ions: loses

Question 12

Marine

Answer 12

• Hypoosmotic
  Water: loses, Ions: gains
  BUT
  Sharks:
• Not hypoosmotic
• Have high levels of urea and trimethylamine oxide (organic molecule that protects proteins from damage by urea)
• Sharks are hyperosmotic but hypoionic to ambient water

Question 13

Kidneys

Answer 13

• Important for conserving water
  in terrestrial (dehydrating) environments
• Made of nephrons which filter the blood - some water / ions are reabsorbed (in the Loop of Henle)
  e.g. Kangaroo rats have a longer LOH which means more water conservation

Question 14

Anti-diuretic hormone (ADH)

Answer 14

• A negative feedback pathway is used to maintain homeostasis in the blood
  (ion concentration/volume of the blood)
• When dehydrated, ADH is released, water is reabsorbed and less urine is expelled