Lecture 26 Flashcards
What is the primary function of mammalian kidneys?
A: Excretion and osmoregulation — they filter the blood, remove nitrogenous waste, and conserve water, which is a key terrestrial adaptation.
What are the main components found in the filtrate of the nephron?
A: Salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules.
What is the significance of the nephron structure in the kidney?
A: It allows for stepwise processing and reabsorption of essential substances like glucose and salts through proximal/distal tubules and the loop of Henle.
What are the three levels of biodiversity?
A: 1. Genetic (within & between populations)
2. Species-level (e.g., threatened or endangered)
3. Community and ecosystem-level biodiversity.
What are the major human-related threats to biodiversity?
A: Habitat loss, overharvesting, introduced species, and global change.
What defines an introduced species?
A: A species that humans move from their native location to a new geographic region. These can disrupt ecosystems due to lack of native predators or pathogens.
Why are zebra mussels considered ideal invaders?
A: High dispersal, no need for fish hosts, fast reproduction, environmental tolerance, and ability to attach to hard surfaces.
Where are zebra mussels native to?
A: The Caspian and Black Sea regions.
How did zebra mussels arrive in North America?
A: Via ballast water from ships in the Great Lakes in 1986.
What are the ecological impacts of zebra mussels?
Outcompete native mussels
Clear plankton from food webs
Increase toxic algal blooms
Cost millions in infrastructure damage
Alter fish spawning grounds
What can individuals do to prevent the spread of zebra mussels?
Clean, Drain, Dry boats and gear
Report sightings to NBISC or DFO
Educate others
What characteristics help species become successful invaders?
High reproduction rate
Phenotypic plasticity
Ecological competence
Tolerance to varied environments
