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Ecology 355-Exam 2

Terms in this set (36)

C3 photosynthetic pathway
The ancestral photosynthetic pathway; simplest (occurs all in mesophyll cells) and most efficient of the three but is is slowed when oxygen competes with carbon dioxide.
C4 photosynthetic pathway
A biochemical pathway involving the daytime uptake of CO2 by the enzyme phosphoenol pyruvate carboxylase (PEP case) in mesophyll cells; the carbon is then transferred as a four-carbon acid to the bundle sheath cells, where CO2 is released to the Calvin cycle for sugar synthesis.
CAM photosynthetic pathway
A derived photosynthetic pathway; includes temporal separation of carbon fixation (night time) and sugar production (day time); minimizes water water loss.
Biome
A group of ecosystems that share similar climates and typical organisms.
sexual selection
A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
intersexual selection
Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.
intrasexual selection
A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex.
secondary sexual characteristics
Bodily structures that change with sexual maturity but are not directly related to reproduction.
inclusive fitness
The total effect an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives to increase the production of their offspring.
kin selection
Selection in which individuals increase their inclusive fitness by helping increase the survival and reproduction of relatives (kin) that are not offspring.
cooperative breeding
In humans and certain other species, a system involving networks of support in which individuals other than parents contribute resources toward rearing the young.
Population
A group of individuals that belong to the same species and live in the same area.
clumped distribution
The most common type of population distribution where many members of the population live close together.
random distribution
Distribution in which the location of members in a population is totally random, location of each individual is determined by chance.
uniform/regular distribution
organisms are spread out in a fairly regular pattern. This occurs often where individuals must compete for a limiting resource, such as water or light.
abundance
A great or plentiful amount.
survivorship curve
Graph showing the number of survivors in different age groups for a particular species.
population dynamics
The study of how complex interactions between biotic and abiotic factors influence variations in population size.
fundamental niche vs realized niche
Fundamental niche is niche potentially occupied by that species; realized niche is the portion of its fundamental niche that it actually occupies in a particular environment.
static life table
A life table that quantifies the survival and fecundity of all individuals in a population during a single time interval.
cohort life table
A life table that follows a group of individuals born at the same time from birth to the death of the last individual.
Age Distribution
A model used in population geography that describes the ages and number of males and females within a given population; also called a population pyramid.
fecundity
The ability to produce an abundance of offspring or new growth.
semelparity
Reproduction in which an organism produces all of its offspring in a single event; also known as big-bang reproduction.
iteroparity
Reproduction in which adults produce offspring over many years; also known as repeated reproduction.
net reproductive rate
The total number of female offspring that we expect an average female to produce over the course of her life.
Per capita intrinsic rate of increase
The maximum per capita growth rate for a population.
generation time
The period between the birth of one generation and the birth of the next generation.
range
The area where a particular species can be found during its lifetime.
thermal stratification
A change in the temperature at different depths in the lake, and is due to the density of water varying with temperature.
what is an example of intrasexual selection?
A strong large, aggressive male primate tries to keep other male primates away from the females so that he can be their primary mate.
what is an example of intersexual selection?
Peahens choose peacocks with brightly colored tails in order to reproduce or mate. However, there is no physical competition between peacocks with brightly coloured tails and other male peacocks.
Why are the tropics (warm wet climates) near the equator, whereas most deserts are near 30 degrees N or S latitude?
High temperatures and high precipitation are the results from rising, low pressure air near the equator. Higher latitudes have dryer air and are more humid which results in temperatures decreasing as latitude increases. Since earth is tilted on its axis, the greatest amount of solar energy per unit area is absorbed between the 30 degree N and S latitude.
Why does ice float?
When water cools, the hydrogen bonds adjust to hold the negatively-charged oxygen atoms apart, which prevents the ice from becoming any denser.
What property of water results in the stratification of water layers in lakes in Michigan?
The warming of the surface of the water by the sun causes water density variations and initiates thermal stratification. Cooler, denser water settles to the bottom of the lake forming the hypolimnion (cold layer of water that lies beneath the thermocline).
How do the round shape of the earth, its angle of daily rotation, and its annual revolution contribute to spatial variation in temperature and precipitation, and to the existence of seasons?
Tilt causes seasons to occur, and because the Earth is a sphere, the surface gets much more intense sunlight (heat) at the equator than at the poles.
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