Lab Practical 2 EX.9
Population
A group of individuals of the same species geographical location at the same time. ex) college campus
Community
All the populations that occupy the same geographical location at the same time.
Natural selection is the process by which forms of life having traits that better enable them to adapt to specific environmental pressure survive. How does competition influence natural selection?
Competition influences natural selection by the finite amount of resources available, those members of species best adapted to take advantage of the resources are more likely to reproduce and pass on their genes to the next generation.
Compare the types of survivorship curves you would expect to find in human populations in industrialized countries with good health care versus african countries with a high mortality rate from HIV.
I would say african countries that have a high mortality rate from HIV would be considered Type 3 compared to industrialized countries with good health care would be Type 1. Reason being b/c industrialized countries have better health care and less deaths.
Why is a pyramid of numbers not always a good example of the flow of energy through a food chain.
Sometimes there is no single species at the top of the food chain so a pyramid is not the best representation. There is a limit to the trophic levels set by practicality. You cannot have an infinite pyramid b/c energy is inefficiently lost at each level.
Describe the different survivorship curves.
Survivorship curves: illustrate the percentage of individuals in a population that survive over the average life span of that species. Type 1: low mortality rate in young, most individuals die in old age; typically, type 1 organisms have a low birth rate and nurture and protect their young. Ex) humans and large animals Type 2: the mortality rate is relatively steady throughout the life span; ex) birds, small mammals and reptiles. Type 3: The mortality rate for the young is very high, few individuals reach old age; typically, type 3 organisms have a very high birth rate and provide no protection to their young; ex) frogs, sea urchins, and insects
What is an ecosystem?
The combination of a community with the non-living physical and chemical environment.
How can the growth of a population be slowed by its own numbers?
The growth of a population can be slowed because there is an increase in consumption, that could lead to less resources available.
trophic levels
arrangement that shoes how energy moves through an ecosystem as organisms on one level eat organism from the level below and the nutrients obtained are then used to produce energy
interspecific competition
between two different species
Mutualism
both organisms benefit
Consider the human life cycle, what survival strategy do we use?
competition for resources as omnivores. lots of maternal care, low birth rate
Carnivores
eat animals ex) snakes, lions
Omnivores
eat both plants and animals. ex) humans, bears
Herbivores
eat plants ex) insects, rabbits, deer
Parasites
extract nutrients from a living host they live in or on. ex)tape worms, and some protozoans
Intraspecific competition
members of the same species compete
Decomposers/detritivores
obtain nutrients by breaking down the remains of dead organisms and other organic wastes. ex) fungi and bacteria
How would you classify your nutritional approach (carnivore, herbivore, or omnivore)
omnivore: Eats both veggies and meat for a balanced diet.
commensalism
one organism benefits without harming the other one
Paratism
parasite is benefited and the host is harmed
food web
presents a more accurate picture of feeding patterns.
Why are food webs a more accurate portrayal of feeding relationships in an ecosystem than food chains or pyramids?
the problem with food chains is that few organisms rely on only one source of food. The food web presents more of a better depiction of feeding patterns. Food web illustrates the interactions between all species living in a given area.
competition
when organisms compete for the same resource
