Bio Honors Unit 3.2 & 4.1 Study Guide

Explain why and in what ways a food web is "better" than a food chain

A food web is better than a food chain because it is more detailed and specific. A food web includes animals that can be placed different trophic levels, so it specifies what animals eat what and how the environment works together.

Explain what is meant by a trophic cascade

A trophic cascade is a series of changes in population sizes at different levels in a food chain. Predators at the higher trophic levels keep the population of the organisms at lower trophic levels in check. As we saw in the video, if these predators are taken out of the ecosystem the middle trophic levels will take over because there are no organisms there to regulate them. Ex. starfish→ anemone→ barnacles. When starfish are removed the anemone takes over because the starfish no longer consumes them.

how to explain how adaptations arose in a way that is compatible with the theory of natural selection

Adaptations are changes in species/populations that could be passed down if they are hereditary. Different adaptations could be either beneficial or disadvantageous in a species's environment. Some adaptations are created to increase the animal's chances of survival. Natural selection occurs because animals with a beneficial adaptation are more likely to survive and therefore are more likely to reproduce.

the significance of Alfred Wallace and the letter he sent to Darwin

Alfred Wallace was a collector for eight years observing similar characteristics of different species similar to Darwin, years prior. Similar to Darwin he beloved you cold connect all species to one another "like tree branches," every species is the modern form of an original one, species come from pre-existing, nearby species and that when there was massive death within a species/population (due to things like disease and bad weather) the species with variations and advantages would be the only ones who survive, reproduce and cause the species to change. He sent the letter to Darwin which was significant because it allowed Darwin to realize that he and Wallace had studied different species but concluded the same theory: species come from other species because organisms within a species vary, and only some survive when massive death and casualties.

What an adaption really is

An adaptation is the process by which an organism alters certain characteristics in order to better suit their environment.

Explain why some aquatic biomass pyramids are smaller at the producer level than at the primary consumer level

An aquatic ecosystem can exist with a smaller biomass at the producer level because Zooplankton eat so much, so it doesn't matter that there is less food, and the phytoplankton reproduce rapidly so they can easily replace those who died.

Interpret an energy pyramid, such as the one in Figure 20.28

An energy pyramid illustrates the cumulative loss of energy with each transfer of the food chain only a tiny amount of energy stored by photosynthesis reaches a tertiary consumer (such as a snake) *just know how to look at a pyramid and see how much energy was lost and where

Descrive what an energy pyramid shows

An energy pyramid shows how little energy from the primary producer (bottom of the pyramid) actually gets to the predators at the top. All this energy is lost through multiple processes, however most is lost through heat.

Explain the 10% rule and what happens to the other approximately 90% of the energy taken in at each trophic level

As the energy goes up the trophic levels, the percentage of energy available for the next level decreases. This is because herbivores only eata fraction of the plant material producedthey can't suggest all they consume. Only a certain amount of energy is transformed into an herbivores biomass which is what consumers eat, which decreases the percentage of energy consumed even more. This then occurs in every other trophic level where they eat the biomass and therefore obtain 5-20% amount of energy. The other 90% is used for egested waste/day, heat loss, and respirations

Name and explain the relationships between the different trophic levels in a food chain

Bottom -> Top: Producers (convert light energy into chemical energy stored in the bonds of organic compounds like sugar; ex, plants phytoplankton, algae) -> Primary Consumers (herbivores, eat producers, ex. snails, birds, zooplankton) -> Secondary consumers (Carnivores, eat primary consumers, ex. mice, small fishes) -> Tertiary Consumers (eat secondary consumers, ex. snakes) -> Quaternary Consumers (Eat tertiary consumers, rare ex. hawks, whales) Decomposers: Many live in soil or mud at button of lakes and oceans where they secrete enzymes that digest molecules in organic material and convert them into organic forms

State the products of cellular respiration

CO2, H2O, Energy for the cell to use

Explain why there are no tenth-level connsumers

Due to the 10% rule, there is less energy available for the organisms in higher trophic levels, so by the 5th trophic level, those organisms are already at a smaller population than the species at the bottom. Since there is not enough energy for organisms at higher trophic levels to sustain the higher trophic levels, there is no way there could be a tenth-level consumer.

the difference between natural selection and evolution

Evolution is the change in population over time and natural selection is the mechanism for that change.

Name some of the ways that interactions between different species has affected evolution of those species

Examples: cryptic coloration, warning coloration, mimicry, and flavorful These adaptations are made to avoid predation

the importance of Darwin's trip on the Beagle, and the importance of his work on artificial selection after he returned

His trip to the Beagle was extremely important because it was the start of his scientific career. It allowed him to collect fossils and plants, to gain curiosity, and start to discover and understand the origin of species. The trip ultimately led to his entire career. He was able to observe the difference between the same kind of species that had different characteristics. When he got back he focused on the idea, "species might change" and instead of God creating different types of characteristics for each mocking bird (ex. used in the vid.), he believed that there was one type of hummingbird that adapted characteristics when the traveled to different islands. Later believed that species change into new species (over time one type of mockingbird somehow became three). The origin of species was natural, not divine. Created "family tree" explaining that all species are associated/related to each other. Species come from other species.

the difference between homologous structures and analogous structures

Homologous structures implies common ancestry don't always have the same function ex. whales fin and human arm Analogous structures similar structures in different organisms similar functions don't imply a shared ancestry

Discuss species diversity in communities, and explain the role that keystone species play

Species Diversity 2 factors # of different species relative abundance of each species Diverse ecosystems are more resilient to disturbance Keystone species Often consumers and helps maintain diversity within communities Helps diversity because they eat species to regulate the number of organisms in the species (in the environment) Ex: Starfish and oysters. When starfish were extracted from their environment, the number of oysters increased since their consumers were gone. It also decreased the population of other species because the oysters were taking up more land

why a teleological explanation of a biological observation is unsatisfactory

Teleological explanations focus only on the result or purpose, not the cause of an observation. It is unsatisfactory because it is simply the result and not the true cause of the observation.

Explain the competitive exclusion principle

The principle that when two species compete for the same critical resources within an environment, one of them will eventually outcompete and displace the other.

What fitness really is

The success of an organism in producing successful offspring

Explain why it is easier on the environment for a human to eat less meat and more plant-based foods

This is from the Mastering Bio assignment: The world population is estimated to reach 9 billion by 2050. Many are concerned about how we will feed an ever-increasing human population and the impact growing more food will have on the environment.In response to these concerns, some groups advocate for humans to consume less meat and to incorporate more energy-efficient primary producers (plants) into our diets.

the definition of a population

a population is a number of all the organisms of the same group or species who live in a particular geographical area and are capable of interbreeding.

The components of Darwin's theory of evolution by natural selection

a) A pop. will eventually produce more offspring than the environment can support. Some individuals will have more surviving offspring than other individuals. b) Populations naturally show variety. New variations are rare and arise by chance. c) Some variations affect fitness (success in producing successful offspring). Fitness may depend on environmental conditions. d) Inborn variations are often heritable (get passed on to offspring). e) Traits that improve fitness will be more common in future generations because individuals with those traits will leave more offspring (who will also have those traits).

Explain biomagnification (and distinguish between biomagnification and bioaccumulation)

biomagnification: the process by which toxins consumed become more concentrated as they pass through the food chain. magnification of chemicals → such as PCB's Organisms can't metabolize many toxins and after consumption the chemicals remain in the body. These toxins become concentrated as they pass through the food chain. ex. zooplankton feed on phytoplankton contaminated by PCBs, then the cod feed on these zooplankton and become contaminated too concentration in cod=higher top of the food chain has the highest concentration of PCCBs (humans) In contrast, bioaccumulation occurs within an organism, where a concentration of a substance builds up in the tissues and is absorbed faster than it is removed.

Distinguish between interspecific competition and intraspecific competition

interspecific competition: competition between two different species. ex. when gown separately organisms grow just fine, but when they are combined in the same habitat they are not just fine and it interfere with their growth. Intraspecific competition: occurs between members of the same species. ex. two male birds of same species compete for mates tp create offspring. or two birds of same species compete for food or shelter

Give a scientific definition of niche

niche: all ecological factors (abiotic and biotic) in a space in order to survive.

You should understand: the information in the "Common Misconceptions about Evolution by Natural Selection" handout

populations evolve, individuals do not evolution just occurs with no plan in mind many people came before Darwin there is no good or bad in evolution, only evolution individuals do not alter themselves in response to the environment successful traits persist and increase in frequency over time

Explain the difference between a primary consumer and a secondary consumer, etc.

primary consumers: consumers that eat the producers. ex. herbivores. They eat plants (i.e. primary producers and are the first level of consumers. They are directly after the producers on the food chain. secondary consumers: eat the primary consumers. This includes carnivores who eat primary consumers. (ex. a lion eating a caterpillar) They are third in the food chain and after the primary consumers. the pattern continues, tertiary consumers (third level of consumers) eat secondary consumers, and so on..

Define primary production and state what organisms are primary producers

primary production: rate at which an ecosystem's producers convert solar energy to chemical energy (stored in organic compounds) examples of primary producers: they acquire energy from the sun algae plants trees moss essentially anything that incurs photosynthesis