study guide Flashcards
(30 cards)
What are the main factors driving current species extinction?
Habitat destruction
overexploitation
invasive species
pollution
climate change.
How do human population growth and resource consumption threaten ecosystems and human welfare?
They increase demand for:
food
water
energy
leading to resource depletion
pollution
biodiversity loss.
What are examples of human impact on the biosphere through pollution and resource depletion?
Deforestation
overfishing
water contamination
fossil fuel combustion
agricultural runoff
plastic waste accumulation.
How do CO₂ and CH₄ contribute to climate change?
They trap heat in the atmosphere, causing global warming and climate instability.
What are some consequences of climate destabilization?
Biodiversity loss, food insecurity, increased disease spread, and extreme weather events.
What is alternation of generations?
A life cycle alternating between multicellular haploid gametophytes and diploid sporophytes.
What do sporophytes produce and by what process?
Spores by meiosis.
What do gametophytes produce and by what process?
Gametes by mitosis.
How are flowers, fruits, and seeds adapted to life on Earth?
Flowers attract pollinators; fruits help seed dispersal; seeds protect and nourish embryos
How do r- and K-selected strategies apply to plants?
r-selected plants grow fast and produce many seeds; K-selected plants grow slower with fewer seeds and longer life cycles.
What are some examples of asexual reproduction in plants?
Runners (strawberries), bulbs (onions), and stem cuttings.
How do plants absorb nitrogen, and in what form?
Through their roots as nitrate (NO₃⁻), which is used to synthesize amino acids.
What are examples of asexual reproduction in animals?
Budding (hydra) and parthenogenesis (whiptail lizards).
What is a hermaphrodite?
An organism with both male and female reproductive organs (e.g., earthworms).
How do r- and K-selected strategies apply to animals?
r-selected = many offspring, no care (e.g., insects)
K-selected = few offspring, lots of care (e.g., elephants).
What is innate immunity?
The non-specific, first line of defense including skin, inflammation, and fever.
What is acquired immunity
Specific immunity involving B-cells (antibodies) T-cells (cell killers), developed after exposure
What is hypersensitivity?
An excessive immune response like allergies or autoimmune disorders.
What is exponential growth?
Population increases rapidly with no limiting factors (J-curve).
What is logistic growth?
Population growth slows as it approaches carrying capacity (S-curve).
What are density-dependent factors?
Factors like food, disease, and space that limit population size as it grows.
How do plants and animals differ in nutrient acquisition?
Plants synthesize nutrients from soil and air; animals digest organic matter.
What is the 10% rule in trophic levels?
nly about 10% of energy is passed to the next trophic level.
Where do most humans get their drinking water from?
Flowing surface water like rivers, which is limited in supply.
