Test 3.1 Flashcards
(26 cards)
What is natural selection?
The process by which organisms better adapted to their environment tend to survive and reproduce more successfully.
What is a predator-prey dynamic?
A relationship where one organism feeds on another, affecting both population sizes over time.
What are limiting factors in population growth?
Factors like food, water, space, and predation that control population size.
What are density-dependent factors?
Factors whose effects increase with population density, such as disease or competition.
What are density-independent factors?
Abiotic factors like weather or natural disasters that affect populations regardless of size.
How does mark-recapture estimate population size?
By capturing, marking, and releasing individuals, then recapturing and using the ratio of marked to unmarked.
Why are population estimates important?
They help track population trends and assess conservation status.
What is a keystone species?
A species with a disproportionately large effect on its ecosystem’s structure and biodiversity.
How do keystone species influence community dynamics?
Their presence or absence can shift species interactions and stability.
What is an ecosystem engineer?
An organism that creates, modifies, or maintains habitat, like beavers building dams.
How do ecosystem engineers affect ecosystems?
They change the physical environment, which influences other organisms.
What is altruism in biology?
Behavior that benefits another individual at a cost to oneself, often explained by kin selection or reciprocity.
What is Batesian mimicry?
A harmless species mimics a harmful one to avoid predation.
What is Müllerian mimicry?
Two or more harmful species mimic each other for mutual benefit.
What is mutualism?
An interaction where both species benefit, like pollination or gut bacteria.
What is intrasexual selection?
Competition among the same sex (usually males) for mates.
What is intersexual selection?
Mate choice, often by females selecting males with desirable traits.
What are common mating systems in animals?
Monogamy, polygyny, and polyandry.
What are the benefits of monogamy?
Both parents care for offspring; higher certainty of paternity.
What is a cost of polygyny?
Only one parent typically raises offspring, increasing their burden.
How does energy enter a food web?
Primarily through photosynthesis or chemosynthesis by primary producers.
What direction do arrows in a food web point?
From prey to predator, showing the direction of energy flow.
What is the difference between biomass and energy pyramids?
Biomass pyramids show mass; energy pyramids show energy transfer between trophic levels.
How do marine and terrestrial pyramids differ?
Marine biomass pyramids can be inverted due to rapid consumption of primary producers.
