bio exam hw questions

• why is population ecology important for solving real world problems?

  is essential for solving real-world problems including protecting endangered species, or controlling pest species
• what is population ecology?

  the study of the # of organisms in a particular place
• define population?


  a group of interacting individuals of a single species within a particular area
• what is population size?

  total # of individuals in the population
• what is population density?

  the # of individuals per unit of area
• what determines whether a population increases or decreases in size?

  Birth rate, death rate, immigration, and emigration
• what factors can limit the growth of natural population?

  food shortages, lack of space, disease, disturbances.. ect
• what is sustainability?


  a process that can continue indefinitely without using up resources or causing serious damage to the environment
• what is ecological footprint?

  a measure of sustainability, the area of productive land and water that an individual or population requires in order to produce resources and absorb waste
• how do groups of animals differ in body plans?

  presence of true tissues, patterns of gastrulation, body symmetry, organs/organ systems, body cavities, segmentation of the body
• how do sponges exhibit division of labor among specialized cell types?

  each cell function in a sponge are largely independent from other cells
• what is radial symmetry?

  it gives sessile animals greater access to their environment, body is arranged around a central axis
• what is bilateral symmetry?

  divideds the body into two halves that mirror eachother, enables rabid and efficient locomotion
• what is locomotion?


  ways an organism moves from one place to another. like walking, flying, slithering, swimming..
• what are organ systems?

  2 or more organs working together
• what are cnidarians?


  Invertebrate marine animals like jellyfish and sea anemones. they lack organs and have cnidocytes (stinging cells)
• what are protostomes?


  group of animals like insects, crabs, snails, and worms. animals where the mouth forms first as the embryo develops
• what are annelids?


  Segmented worms. they have a simple brain connected to a pair of nerve cords
• what are mollusks?


  Invertebrates animals like snail, clams, and octopuses. some have a protective shell, but not all animals like squids and octopuses. they hve internal organs called visceral mass
• what are arthropods?


  animals like spiders, insects, crabs and lobsters. they have segmented bodies and exoskeletons
• what advantages do wings provide to insects?

  escaping, finding food and mates, dispersing offspring
• what is metamorphosis?


  Transformation
• what is incomplete metamorphases?

  when the animal goes through gradual change as it matures, but doesnt fully transform its body
• what is complete metamorphises?

  dramatic transformation, changing entire body structure as it grows up
• what are tetrapods?


  terrestrial Four-limbed vertebrates, includes amphibeans
• what are the three main group of mammals?

  Monotremes, marsupials, placental mammals
• what are monotremes?


  Mammals that lay eggs.
• what are marsupials?


  Mammals with pouches.
• what are eutharians?


  nourish young internally through placenta
• what is sessile animal?

  An animal that is permanently attached to a surface and cannot move.
• what does growth rate = ?

  grow rate = (birth + immigration) + (death + emigration)
• what is exponential growth?


  when a population increases by a constant rate over a constant time interval, such as 1 year or one generation
• change in population can be calculated by?

  dN/dt=rN