Study Guide Questions Flashcards
Explain bioaccumulation. How could the build up of DDT (an insecticide) in worms affect other organisms?
Bioaccumulation is the accumulation of harmful chemicals in organisms, that is then passed down the food chain because it can’t be digested, which harms every animal in the food chain.
Worms are primary consumers, which means that they are the first animals in the food chain. Every animal that comes after the worms will be affected by the DDT in the worms, because it gets passed down the chain.
The animals will most likely become sick and die early, which could affect the population of the animals long-term. If all worms die because of the insecticide, the birds that eat them won’t have anything to eat and also die, and so will the snakes that eat the birds, etc.
What are the different feeding modes of organisms? What organism breaks down food and recycles the nutrients?
Herbivore = Eats plants, primary consumer
Carnivore = Eats meat, Secondary, Primary, etc.
Omnivore = Can be any consumer, humans
Decomposers
Explain why there are not usually more than 4 consumers in a food chain, using keywords.
The 10% rule explains that only ten percent of energy is transferred from one trophic level to the next, meaning the animals at the top of the food chain don’t get as much as the producers and primary consumers.
The nutrients have already decreased greatly by the time a quaternary consumer comes around, so there is no point in there being more consumers, since they will be getting so little nutrients.
What are the four ecosystem services? Describe each and give your own example of each one.
Cultural services, provides things beneficial for human well-being, like a group of silly elephants by a village that makes people happy.
Provisional services, provides physical things for humans, like wood for building.
Supporting services, provides the basic chemical processes necessary for ecosystems, like photosynthesis or the water cycle.
Regulating services, provides necessary processes for ecosystems, like pollination or water filtration.
Examine the food chain: Cow —-> Grass —-> Rabbit.
What is incorrect about this food chain? Explain using keywords, and in reference to what the arrows represent
The arrows represent in what direction the nutrients go, so this food chain is incorrectly drawn because the nutrients do not go from the cow to the grass, because the grass can’t eat anything. It is a producer, meaning it produces its own nutrients.
The correct way to draw this food chain is: Grass –> Rabbit –> Cow, because the nutrients go from the grass (producer,) to the rabbit (primary consumer), to the cow (tertiary consumer.)
A. Create a food chain with 5 organisms. Label the energy levels, trophic levels and energy percentage for each organism
B. Add two other food chains to the food chain created above, to create a food web.
Sun –>
Algae, Producer, Trophic Level 1, 100% –>
Shrimp, Primary Consumer, Trophic Level 2, 10%
–>
Small fish, Secondary Consumer, Trophic Level 3, 0,1% –>
Bigger fish, Tertiary Consumer, Trophic Level 4, 0,01% –>
Human, Quaternary Consumer, Trophic Level 5, 0,001%
(Shark eats bigger fish, humans eat shark. Tadpoles eat algae, small fish eat tadpoles, bigger fish eat tadpoles.)
Why are whales and humans mammals and relatives, but also look so different from the outside?
Whales and humans have a common ancestor, but we both went our own way by adapting to our own environment.
Whales live in water and therefore need fins and the ability to breathe underwater, while we humans need legs to walk on land and hands to hold things.
Through mutations and natural selection, we have adapted and gotten the traits that are most beneficial for our survival.
Breeders specifically mate one breed of dog with another breed to get a specific trait they want in a dog. Is this natural selection? Explain why or why not.
This is not natural selection, because it is not nature that is controlling the traits of the dogs, but us humans.
Many dogs today have traits that are incredibly unbeneficial to their survival, because we keep breeding them so that they have those traits, because we find them cute (very cruel.) If they were allowed to evolve naturally, the unbeneficial traits would disappear overtime, because the dogs with those traits would have a harder time surviving, meaning a smaller chance of reproducing and giving their traits to another generation. The most “fit” would survive.
Use the 4 aspects of evolution to describe why birds evolved from dinosaurs who survived the mass extinction event 65 million years ago.
After the meteor, the ozone layer was covered in a layer of dust which prevented the sunlight from reaching the ground. This caused a majority of the plants to die, and also the herbivores and the majority of other dinosaurs.
Mutation and variation: Some smaller dinosaurs survived, and a mutation caused a variation – wings.
Natural selection: The dinosaurs with wings had an easier time surviving since they could fly above the inhospitable ground, so they were able to reproduce more and –
Heredity: – pass their genes to the next generation, who continued this trend.
Time: Evolution is a lengthy process since genes need to be passed down through generations, but overtime, the trait becomes more dominant. That is why all birds have wings today – it is beneficial to them.
What roles did water play in the evolution of life?
Simply enough, life just requires water, so without it there can be no life.
It is a solvent and reactant, meaning it plays an important role in many chemical reactions, and it was through chemical reactions that we got life on earth. (Simple compounds –> amino acids, –> purins, –> RNA, –> DNA, –> Proteins, –> Life.
How did early life on Earth create the atmosphere we have now? Why was this important for the origin of life?
The first cells on Earth created chloroplasts, which contain chlorophyll, meaning they were able to photosynthesize. Through photosynthesis, we got oxygen, but also an ozone layer, which keeps the oxygen on Earth.
Oxygen is essential to life and all of our cells require it, so without it there could be no life.
The ozone layer also provides protection from the sun’s strong UV rays, so with water, oxygen and protection, the earth was an ideal environment for life to form.
