Midterm 1 Flashcards
Define Acclimation
adjustment to single environmental factor
Define Acclimatization
adjustment to multiple environmental factors
Define thermogenesis
adjustment of metabolic heat production to maintain body temp
Define osmolarity, and describe what it does
it’s the solute concentration in a solution and it determines the movement of water across a selectively permeable membrane (water goes from low solute concentration to high)
How many living animal species are there?
1.3 million
What are the 5 stages of embryonic development? And where does cleavage occur?
1) Zygote
Cleavage
2) 8-cell stage
Cleavage
3) Blastula
4) Gastrulation
5) Gastrula
What characteristic defines Ecdysozoans? (Ecdysis)
they’re invertebrates that shed their exoskeletons in a process called ecdysis
What does the word Arthropod mean?
Jointed feet
How long ago did the common ancestor of all animals live?
It lived between 700-770 million years ago
What Protist resembled the common ancestor of all living animals?
Choanoflagellates
What 3 pieces of evidence suggest that choanoflagellates resemble the common ancestor of all living animals?
1) cell morphology
2) cell morphology unique to animal cells
3) DNA homologous
What 4 things do physical laws constrain?
1) strength
2) movement
3) diffusion
4) heat exchange
What is physiology the study of?
Biological functions
What are the 3 internal exchange surfaces of complex animals?
1) Lungs: wet sponge-like surface for gas exchange
2) Small intestine: finger-like structures to expand surface area, thus increasing nutrient absorption
3) Kidneys: blood filtered across surface of long, narrow blood vessels
Define Regulators and give one example
They use internal control mechanisms to moderate internal changes in the face of environmental fluctuations. Example: Otter
Define Conformers and give one example
They allow their internal conditions to vary with certain external changes, Example: Large-mouth Bass
What do mechanisms of homeostasis do?
They moderate changes in internal environment
Is homeostasis a positive or negative feedback loop? And explain why
Negative because fluctuations above the set point act as stimulus, which is detected by a sensor, and it triggers a response, which returns the variable to the set point
In animals and plants, what rhythm governs physiological changes?
Circadian rhythm
Define Thermoregulation
Maintain internal temp within a certain range
Define ectothermic and give examples
Animals that gain heat from external sources and can tolerate more variation in internal temp. Examples: Fish, invertebrates, amphibians, and non-avian reptiles
Define endothermic and give examples
Animals that generate heat via metabolism, which is more energetically costly as they maintain internal temps even with external fluctuations. Examples: mammals and birds
What are 4 things to balance heat loss and heat gain
1) Radiation
2) Evaporation
3) Conduction
4) Convection
What are 5 adaptations that help animals thermoregulate?
1) Insulation: Skin, blubber, fur, feathers
2) Circulatory adaptations: marine animals = countercurrent exchange, circulate blood near surface
3) Cooling by evaporative heat loss: sweating, bathing, panting
4) Behavioural responses: Postures in invertebrates to min or max solar absorption, honeybees huddling
5) Adjusting metabolic heat production: shivering, moving, nonshivering (mitochondria increases metabolic activity)
Why are specialized compartments for digestion important?
Important as it reduces the risk of an animal digesting its own cells and tissues
What kind of digestion is used by simple animals?
Intracellular digestion where food particles are engulfed by phagocytosis
What kind of digestion is used by complex animals?
Extracellular digestion where food is broken down outside of cells
What is broken down in the alimentary canal due to the amylase in our saliva?
sugars
What do parietal cells and chief cells do in the stomach?
Parietal cells secrete H+ and Cl- separately into the stomach of the lumen and Chief cells secrete inactivated pepsinogen which is activated to pepsin in the lumen of the stomach when coming into contact with HCl
What’s the pH of the stomach and what are gastric juices made of?
pH = 2 and it’s made of HCl and pepsin (protease that breaks down proteins into smaller peptides)
What protects the stomach lining?
mucus