A unit of heredity(traits) in a living organism that is passed to offspring
Organized structure of DNA and protein found in cells
Human cell nucleus
23 Pairs of chromosomes exist in what?
Deoxyribose Nucleic Acid
DNA molecules are large and complex. They carry the genetic code that determines the characteristics of a living thing.
What is a Gene?
A gene is a short section of DNA. Each gene codes for a specific protein by specifying the order in which amino acids must be joined together.
Type of cell division that leads to growth repair. When a cell divides by this process two new cells for where each cell is identical to the other one and the cell they were formed from.
Changes in attributes of a population over time.
A measure of the contribution of an individual to future generations and can also be called adaptive value.
Higher reproductive rate, longer survival, and higher ____ where an organism leaves more descendants.
All life forms vary genetically within a population
Genetic traits are inherited from parents and are passed on to offspring.
Organisms with traits that are favourable to their survival and reproduction are more likely to pass on their genes to the next generation
Variation, Inheritance, Selection, Time.
Are a different form of a gene. They can be dominant or recessive
An organism's set of genes that it carries.
Phenotypes at one extreme are selected against
Phenotypes near the mean of the population are fitter than those at the extremes.
Extremes are favoured over the mean
An organism's observable characteristics - which are influenced both by its genotype and by the environment.
Where organisms are found
How many organisms are found in a given area
help us think about what the costs and benefits are
______ is the total variety of life on earth. It includes all genes, species and ecosystems and the ECOLOGICAL PROCESSES of which they are a part
Interactions "structure" communities, maintain diversity, and make ecosystems work
Mutualisms (e.g. pollination, seed dispersal)
Concerned with loss of biodiversity, not just loss of species:
◦ "Fundamental loss of resources in genetics, species, community attributes and ecosystem properties"
◦ maintenance of biodiversity, ecological and evolutionary processes
All species have value independently of their
utility to humans
Species that provide the "greatest good to the
greatest number" (over the longest time) have value
can include both value systems, "To keep every cog and wheel is the first precaution of intelligent tinkering" (Leopold 1943).
Both intrinsic value and utilitarian value
disruption of extensive habitats into small ones, mostly isolated patches of habitat. Edge effects.
loss of species from isolated habitats over time
negative impacts adjacent to habitat boundaries
◦ more sunlight
◦ high winds
◦ tree mortality
◦ invasive species
◦ more predators
part of a patch not impacted by edge effects. Patch size is not always the best predictor of patch quality more about how much of it has a core centre.
evolution and extinction
Biodiversity is not static but constantly changing. 99% of the species that ever lived have gone extinct by mass extinctions, background extinctions, finite lifetimes
assemblages of interdependent species
88% of all extinctions of species is due to __________. Most important and substantial problem.
reduced immigration, re-colonization
Size of habitat
more species, more habitats, larger populations, protects vulnerable species
Shape of habitat
Reduced edge/area ratio, edge effects, disturbance regime: maintenance of disturbance generated patch heterogeneity, includes whole functional units, includes whole environmental gradients
disturbance promotes habitat heterogeneity. By resetting successional sequence in parts of the landscape.
size and disturbance regime
Size of reserve should be as big or bigger scale than likely disturbances
Supports species requiring multiple habitat types. Supports early successional species.
most important problem for aquatic systems (chemical pollutants, acid precipitation
Process by which toxin concentrations increase in living tissues (concentrations increase through the food chain)
_____ rate depends on species and environmental conditions. Many of these offspring don't survive
organisms potential life span under ideal conditions
Actual life span under natural conditions
Mark individuals and observe how many survive from time t to time time t +1
Estimates from decline in relative abundance from age group to age group
the age specific mortality schedule of a population
Early reproduction, invest in high reproductive rates, have little or no paternal care, short life span, high morality rates, tend to occur in unpredictable environments, below carrying capacity`
Late reproduction, low reproductive rates, invest in extensive pate, long life span, low mortality rates, tend to occur in predic, near carrying capacity
most energy is derived from _____.
Energy flow is ______.
Rules of energy
The ___ __ ____ dictate diversity and abundance of organisms
Energy is distributed in complex _____ ____.
First Law of Thermodynamics
Energy cannot be created or destroyed. Energy is simply converted from one form to another.
Second law of thermodynamics