Big Idea 4

8. endosperm - Endosperm is the tissue that protects and feeds the developing embryo in the seeds of angiosperms.  Daffodils, which are angiosperms, have endosperm for their seeds.

10. keystone species - A keystone species is an animal that has played a crucial role in its ecosystem.  Without it, many organisms would be affected.  Jaguars, because they are at the top of the food chain in their natural environments, help to control populations of other organisms in order to stabilize the ecosystem.

11. K-strategist - Species who are K-strategists are large, have relatively long life spans, reproduce in small numbers, and have delayed sexual maturity.  In addition, in their native environments, their population is generally close to their carrying capacity because they are able to compete advantageously for resources and thrive.  Giraffes are K-strategists because they meet all of these requirements to be considered K-strategists.

16. organisms on different levels of the same food chain (4 pictures)

1^st  level (spinach, autotroph, primary producer)

2^nd level (rat, omnivore, primary consumer)

3^rd level (snake, carnivore, secondary consumer)

4^th level (human, omnivore, tertiary consumer)

The food chain is a series of organisms that shows the movement of energy from one movement to the next.  In this food chain, spinach receive energy from the sun, rats eat the spinach for energy, snakes eat rats for energy, and humans eat  snakes for energy, although it is not common and is actually illegal in some areas of the United States.

18. population - The population of a species of an area is the total inhabitants of that species.  It can usually be given a numerical value.  The total population of black and white ruffled lemurs in the Sacramento Zoo is only two.

19. predation - Predation is the act of attacking and feeding on another organism.  All heterotrophs feed on other organisms in order to survive.  Autotrophs, however, do not feed on other organisms, so they do not predate.  An animal has bitten off this shingle oak leaf, a sign of predation.

20. R-strategist - Species who are R-strategists are small, have relatively short life spans, reproduce in large numbers, and can sexually reproduce shortly after birth.  In addition, in their native environments, their populations are much lower than carrying capacity because their environment is unstable and they reproduce too fast to adapt to the environment.  Fish are R-strategists because they meet all of these requirements to be considered an R-strategist.