Lecture 2 Study Guide - Physical Environment
Define a plant:
autotroph, eukaryotic, multicellular, generally adapted to terrestrial existence, have a cell wall, take in CO2
What is an autotroph?
an organism that makes its own food from inorganic molecules
Define an animal:
heterotrophic, eukaryotic, multicellular, take in O2, specialized sensory organs
What is a heterotroph?
cannot make own food, must consume it
What is a theory?
an explanation of a natural phenomenon supported by many observations
What are the basic steps of the Scientific Method?
How much of the earth's surface is water?
71%
How much of earth’s water is drinkable?
3%
How much of the earth’s water is saline versus freshwater?
97% saline, 3% fresh
Which two elements make up water?
- Hydrogen
- Oxygen
What is polarity? How does it work to dissolve substances in water?
unequal sharing of electrons, partial charge attracts other polar molecules, often dissolving them
What is cohesion? Give an example.
water sticks to itself, creates surface tension
What is adhesion? Give an example.
water sticks to other things, helps draw water up the plant
What is transpiration and how does it use cohesion and adhesion?
evaporation through the leaf’s stomata (pores), water “pulls” itself up against gravity
What is capillary action?
water moves up stem in xylem tissue system
What is transpiration?
water evaporates through stomata
What are epiphytes and how do they help plants retain moisture?
live on another plant, usually up high, takes water from the air and traps it
What are the six main macronutrients? Why are they important?
- Nitrogen (N) - proteins, nucleic acids
- Phosphorus (P) - nucleic acids, phospholipids, bone
- Sulfur (S) - proteins
- Potassium (K) - solute in animal cells
- Calcium (Ca) - bone, plant cells, regulator of cell permeability
- Magnesium (Mg) - chlorophyll, enzymes
What is bedrock?
underlying geology
What is soil porosity and why does it vary?
amount of “room” between particles (poor size) based on particle size
Which soils have the highest nutrient availability? Why?
soils with large amounts of clay and organic matter, holds nutrients well
What are two ecosystems that have very poor nutrient availability?
desert and tropical rainforest
What are four adaptations plants have come up with to deal with nutrient limitations?
- root allocation
- succulent, waxy leaves
- spines and hairs
- carnivory (ex: venus fly trap)
What are three ways animals have adapted to nutrient limitations?
- mechanism (secrete excess nutrients)
- resource partitioning (darting to foods where less competition)
- metabolism
What is photosynthesis?
conversion of inorganic carbon dioxide into organic compounds using water and light energy
What is the equation for photosynthesis?
CO2 + H2O + sunlight —> C6H12O6 + O2
How are plants able to absorb different types energy?
some have specialized molecules that absorb some light wavelengths
Why are plants green?
chlorophyll absorbs red and blue light but reflects green