My AP Biology Thoughts – Détails, épisodes et analyse

My AP Biology Thoughts  

Unit #: 8

Welcome to My AP Biology Thoughts podcast, our names are Ramit Dasika, Flavio D’Attilio, Samy Leroux, Landon Schafer, Colin Fahmy and we are hosting this episode called Unit 8 Ecology AND  Today we will be discussing The war between Ukraine and Russia has caused mass destruction to many ecosystems through bombings and other weaponry and how it relates to the AP Biology Curriculum. 

Segment 1: Overview of Topic

•  War 
• The war between Ukraine and Russia has caused mass destruction to many ecosystems through bombings and other weaponry
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Segment 2: Evidence that supports 

• It causes forest fires- Samy
• During the process of runoff, the harmful chemicals are collected in rivers nearby. This causes the  water sources contaminated due to chemical leakage from destroyed industrial plants-Ramit
• During the Russia-Ukrainian War, the Russian soldiers damaged and looted fire engines, computers, and radiation monitoring equipment, while leaving mines and munitions spread across the exclusion zone.-Flavio
• “In the Donbas region, wrecked sewage works gush their contents into rivers and damaged pipelines fill wetlands with oil.”- Landon
• “Most of the exclusion zone was damaged by the invasion and may be contaminated with unexploded ordnance and mines,” according to Oleksandr Galushchenko, director of the biosphere reserve. The larger mammals that constantly move around the reserve – wolves, deer, brown bears, lynx, elk, and recently reintroduced bison – are at particular risk, he says.”-Samy
• “The forests in the zone remain a radioactive tinderbox that, in the event of fires, could send radioactive isotopes on the winds towards Kyiv. The risks of that happening are now much greater, says the UNCG’s forest campaigner Yehor Hrynyk. With fire-fighting equipment looted and much of the exclusion zone dangerous for firefighters to enter, some 65,000 acres has burned since the invasion, and fires continue to smolder in underground peat.”-Colin
• “Many industrial plants are damaged or abandoned;wrecked sewage works gush their contents into rivers; damaged pipelines are filling wetlands with oil; and toxic military scrap is spread across the land.”- Flavio
• “A particular concern is the many coal mines abandoned after 2014. With pumping of water halted, they have so far released some 650,000 acre-feet of polluted mine water into the environment,...

My AP Biology Thoughts  

Unit #: 8- Disruptions to Ecosystems

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Jaiden: Welcome to My AP Biology Thoughts podcast, our names are Jaiden, Adam, and Reena and we are your hosts for this episode called Unit 8, Human Stupidity and Single Use Plastics. Today we will be discussing how single use plastics cause disruptions to the ecosystem and how it relates to the AP Biology Curriculum. 

The Podcast will be broken up into three segments. The first segment will show the general overview of single-use plastics and the second segment will show how these plastics impact the environment and why it relates to the AP Biology Curriculum. Finally, segment three will discuss how we can contribute and reduce single use plastics.

Segment 1: Overview of Topic

• Plastic pollution has become one of the most pressing environmental issues
• According to the Environmental Protection Agency, Americans generated 35.7 million tons of plastic in the United States. 
• Single use plastics are plastics that are used for a brief period of time, before they are thrown away. These include plastic straws, spoons, bottles, and bags
• Microplastics are extremely small pieces of plastic debris. They are generally about five millimeters, or approximately the diameter  an eraser on a #2 pencils,  in length to be considered microplastics

Segment 2: Just how much harm is plastic causing 

• Some plastics such as Chlorinated plastics is harmful for the soil around it along with water sources making it harder for organisms to grow
• It takes 1,000 years for a plastic bag to degrade in a landfill. However, the plastic does not degrade completely but instead becomes microplastics that absorb toxins and continue to pollute the environment.
• An estimated 13 million plastic tons are thrown into the ocean each 
• These small plastic particles may harm our health once they have entered our bodies. Plastic products contain chemical additives. A number of these chemicals have been associated with serious health problems such as hormone-related cancers, infertility and neurodevelopmental disorders like ADHD and autism.
• There are now 5.25 trillion macro and micro pieces, weighing up to 269,000 tonnes. This is because every day, around 8 million pieces of plastic make their way into our oceans.
• Unlike some other kinds of waste, plastic doesn't decompose. That means plastic can stick around indefinitely, wreaking havoc on marine ecosystems. Some plastics float once they enter the ocean, though...

Welcome to My AP Biology Thoughts podcast, our names are Celine, Xavier, and Sofie and we are your hosts for this episode called Unit 7 Natural Selection: Examples of Evolution-Toxic River Fish. In episode 120, we will be discussing the Toxic River Fish and how it relates to the AP Biology Curriculum. 

We want to thank our sources for the information presented in this podcast episode today which include national geographic and NPR. You can find the citations and links to these sources in the show notes.

• To begin with the overview, the species of fish we will be discussing today are the tomcod
• This species of fish lives in the waters of New Jersey and New York, usually found in the Hudson River where pollutants and chemicals such as polychlorinated biphenyl was dumped between 1947-1976 by General Electric companies
• Therefore they developed a gene the resulted in an immunity

• We can see the evolution of Toxic River fish from the molecular Evolution that was changing in DNA sequences. 
• When the pollutants entered the hudson river it resulted in 95% of the fish developing liver tumors.
• The toxins from the electric company entered the nucleus of cells and For some fish it caused a distortion of DNA instructions. This would cause some to most of the fish in the river to get sick and die.
• By chance, the Toxic River Fish had a version of that gene that tolerated the PCB and toxins
• The toxic river fish evolved to handle dangerous chemicals that were dumped in the river and Overtime the toxic river fish that had the resistant gene did better than the fish without it
• Technically they’re not mutants, but the chemicals did give one genetic group an advantage over the others
• This is where survival of the fittest played a role, the fish that could resist toxins would have a higher rate of survival than those without out resistance 
• The ability to resist the toxins caused the toxic river fish to lose some ability to cope with natural stressors like low oxygen or abnormally high temperatures but they still had advantage above other fish

• Biology is the study of biotic organisms, and focuses on the dynamic and behavior. Evolution is 1/12 characteristics of biology.
• It connects to the course because it distinctly shows evolution through natural selection

Welcome to My AP Biology Thoughts podcast, my name is Chloe and I am your host for episode 30 called Unit 8 Ecology: Simpson Diversity Index.  Today we will be discussing how diversity in an ecosystem can be measured mathematically on a scale from 0 to 1.

• The Simpson Diversity Index measures the diversity in a habitat while taking into account the number of species present and the abundance of organisms in each species. There is a simple equation to this Index which will give you a number from 0 to 1 as your answer, 1 being infinite diversity, and 0 being no diversity at all. 

• The Simpson Diversity Index is important because it can help measure how diversity changes in response to a natural event or human impact. For example, scientists could measure the diversity of a habitat before and after a forest fire, and analyze the Simpson Diversity index to understand how the diversity was affected by the fire. Biodiversity in a habitat is important because each species has a specific role, and a significant decrease in the number of species could have a detrimental effect on the habitat. Keystone species are especially important to a habitat because a majority of species rely and depend on them. If the keystone species gets wiped out, it is more than likely for the Simpson Diversity index to drastically decrease.

• When natural selection results in adaptive radiation, the Simpson diversity index can change drastically. For example, Darwin’s Finches created 13 different species which is an increase in the biodiversity of the ecosystem. Another example is extinction. When a natural disaster causes the diversity index to decrease, many niches are left unoccupied, and the habitat can fall apart leading to extinction. 

Thank you for listening to this episode of My AP Biology Thoughts.   For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com.  See you next time!

• "Ice Flow" Kevin MacLeod (incompetech.com)
• Licensed under Creative Commons: By Attribution 4.0 License
•  http://creativecommons.org/licenses/by/4.0/

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Welcome to My AP Biology Thoughts podcast, my name is Nikki and I am your host for episode #29 called Unit 8 Ecology: Symbiotic Relationships..  Today we will be discussing the 3 symbiotic relationships in nature.

• Symbiosis is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms, each termed a symbiont, may be of the same or of different species

• Mutualism: 2 organisms benefit from one another
• Example:  oxpecker (a kind of bird) and the rhinoceros or zebra. Oxpeckers land on rhinos or zebras and eat ticks and other parasites that live on their skin. The oxpeckers get food and the beasts get pest control. 
• Commensalism: 1 organism benefits and other organism is not impacted
• Example :Remora fish have a disk on their heads that makes them able to attach to larger animals, such as sharks, mantas, and whales. When the larger animal feeds, the remora detaches itself to eat the extra food.
• Parasitism: 1 organism benefits and the other is negatively impacted
• Example: Moose and ticks-In such numbers the ticks drain so much blood that the host moose can become anemic and malnourished 

How does this topic fit into the greater picture of ecology?

• Ecology is all about organisms relationships with each other and the environment
• Helps classify how they all fit in with each other
• because they are a major driving force of evolution- coevolution-evolve together. This networking and cooperation among species allows them to survive better than they would as individuals.

Thank you for listening to this episode of My AP Biology Thoughts.   For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com.  See you next time!

• "Ice Flow" Kevin MacLeod (incompetech.com)
• Licensed under Creative Commons: By Attribution 4.0 License
•  http://creativecommons.org/licenses/by/4.0/

• Apple Podcasts
• Spotify
• Google Podcasts  
• Stitcher  
• YouTube  

Welcome to My AP Biology Thoughts podcast, my name is Morgan and I am your host for episode #28 called Unit 8 Ecology: Density Independent vs Density Dependent limiting factors..  Today we will be discussing exactly that, limiting factors in an ecosystem that are considered density independent and density dependent.

Population density- the number of organisms within a given area or ecosystem (how crowded)

Low density ecosystems- organisms spread out (country/rural)

High density ecosystems- lots of organisms in little space (New York City)

Organisms can't grow exponentially or else the earth would be covered in all sorts of animals and population, so we need something that limits the population

Limiting Factor- something in an ecosystem that helps contain a population’s size by slowing or stopping growth, (biotic or abiotic)

Density dependent factors- higher the density of the population, the higher the impact of the limiting factor will be. When there are more organisms, more will be affected

Density independent- regardless of the density (crowdedness/ number of organisms) the limiting factor will decrease the population the same amount. 

• large population and small population would be equally impacted

What are these limiting factors?

Density dependent factors are food, shelter, water, parasites, and predators. 

• There is competition for these resources so in a larger population, more animals are competing for these factors, and more animals will NOT have access to them
• A smaller population has less competition, and will not suffer as much from this lack of resources. 

The same goes for parasites and predators. 

•  Big population has more prey for the predators to feed on and more animals the parasites can attach to 
• A small population will not be as impacted by this type of limiting factor.

Density independent limiting factors - fire, flood, hurricanes, and pollution. natural disasters

• limit populations regardless of size

EXAMPLE: In a large or small ecosystem which has just experienced a hurricane, many of the organisms are going to die off, and the population size will decrease. If the hurricane kills 50% of the population, it is going to have the same impact in both ecosystems. Obviously with a larger...

Welcome to My AP Biology Thoughts podcast, my name is Victoria and I am your host for episode 27 called Unit 8 Ecology: Logistic VS Exponential Growth. 

Logistic Growth: populations grow as fast it can with the limited resource it has to support the growth, making the population growth dependent on the availability of resources, when resources start to decrease or come to a stop, that is called carrying capacity

• Exponential growth may happen for a while, if there are few individuals and many resources. But when the number of individuals gets large enough, resources start to get used up, slowing the growth rate. Eventually, the growth rate will plateau, or level off, making an S-shaped curve. The population size at which it levels off, which represents the maximum population size a particular environment can support, is called the carrying capacity, or K
• Any kind of resource important to a species’ survival can act as a limit, causing the carrying capa For plants, the water, sunlight, nutrients, and the space to grow are some key resources. For animals, important resources include food, water, shelter, and nesting space. Limited quantities of these resources results in competition between members of the same population, or intraspecific competition (intra- = within; -specific = species).

Exponential Growth: resources are unlimited, populations grow as fast as they can, J-shaped curve, the populations faces no predators, like an invasive species

Yeast (logistic growth) 

• a microscopic fungus used to make bread and alcoholic beverages, 
• can produce a classic S-shaped curve when grown in a test tube.
• In the graph shown below, yeast growth levels off as the population hits the limit of the available nutrients. 
• (If we followed the population for longer, it would likely crash, since the test tube is a closed system – meaning that fuel sources would eventually run out and wastes might reach toxic levels).

Spotted Lantern Fly (an Invasive species) or Bacteria 

• The Spotted Lanternfly is an invasive species that destroys fruit crops, trees and plants by hopping from plant to plant, crop to crop, and tree to tree. 
• Although native to regions in China,...

Welcome to My AP Biology Thoughts podcast, my name is CJ and I am your host for episode 26 called Unit 8 Ecology, The Population Growth Equation.  Today we will be discussing The Population Growth Equation.

• Let's start us off with a little bit of background knowledge. The population growth equation was founded in the late 18th century by a couple of biologists. The big one was Thomas Malthus. He saw that populations grew in a geometric pattern. He came up with two models. It is important that we distinguish these two models. One is for logistical growth and the other is for exponential growth. Just like in math, exponential growth is just a line on a graph that looks like a “J”. In fact, in biology, they are often called Exponential growth curves “J” curves. Now logistical growth is similar, up until a crucial point of the population. The curve seems to hit an impasse, or a number on the ‘Y'' axis that will never see a point. Instead of the line continuing up like in an exponential graph, it levels out and shoots to the right, as if hitting a limit. Now this limit is not just a number on an axis. This number represents the carrying capacity of an ecosystem. This carrying capacity is the maximum amount of species in a singular environment. This is most likely due to limiting factors, whether it be biotic or abiotic. Now limiting factors are things in an ecosystem that prevent a species from growing in population without a limit. Now biotic limiting factors are living things, such as lack of food or abundance of predation. These all can limit the total population of a species. Abiotic limiting factors are nonliving things, such as a storm or lack of water or pollution. All of which could kill off a population or make them compete for vital resources. 

• A huge example of exponential growth rates, are any invasive species. Invasive species in the dictionary are defined as having exponential growth in their population. No predators and unlimited resources. Where they go their population is destined to boom and show no signs of slowing. Invasive species we know and hold near and dear to our hearts are stink bugs, the Asian Giant Hornet, Asian Carps, Japanese Beetles, and of course, the Spotted Lantern Flies. All of these came over and had no predators, so naturally, they breed and reproduce unlimitedly. This is a huge problem because their large numbers knock out any other species with the same niche. 

• Enough about the qualitative information about Population Growth Curves, and to the quantitative. Exponential growth curves have an equation of dN/dT = rN. Now, dN/dT stands for the rate at which the population grows. R stands for the maximum growth rate per capita. N stands for the population size. There are other ways to find dN/dT however. The easiest is to subtract the total number of births in a year, with the total number of deaths. For the logistical curves, the equation

Welcome to My AP Biology Thoughts podcast, my name is Helena and I am your host for episode #25 called Unit 8 Ecology: endotherms and ectotherms.  Today we will be discussing the difference between endotherms and ectotherms. 

• Endotherms are organisms that use internally generated heat to maintain body temperature. They typically keep a steady body temperature regardless of their environment due a process called homeostasis. Homeostasis, which are mechanisms like shivering and sweating, keeps an endotherm's internal temperature steady. On the other hand, Ectotherms are organisms that mainly depend on external heat sources in order to regulate their body temperature. Their body temperature fluctuates based on their surrounding environment’s temperature. Their regulation methods include seeking sun when they need heat and shade when they need to cool down. Unlike endotherms, they are able to survive off of a range of body temperatures instead of needing to maintain a set temperature. Since ectotherms use outside sources for heat, they are able to eat much less food than endotherms. Ectotherms have a much lower metabolic rate than endotherms because they use a lot less internal energy to regulate their body temperature. About 50% of ectotherms food energy is used for growth and reproduction, while endotherms use most of their food energy during metabolism to maintain their body temperature. This is why endotherms require 5 to 20 times more food than an ectotherm of the same size. 

• Weather with a t-shirt on, just like every endotherm, you would start shivering. That is unless you are some kind of superhero. On the other hand, if heat generation exceeds heat loss, regulating mechanisms will increase heat loss. So if you were in Florida during August with a winter coat on you would start perspiring, or if you were a very hot dog you would start panting. Now onto Ectotherms, these are the organisms known as “cold-blooded animals”. Ectotherms include most fish, amphibians, reptiles, and invertebrates. When an ectotherm needs to increase its body temperature, it will seek out heat sources. For example, an alligator will bath in the sun, or a lizard will sit on hot pavement. On the other hand, when ectotherms need to cool off, they will seek out shade. For example, a lizard might go hang out under a shaded rock. However, some ectotherms regulate their body temperature by living in environments that have fairly constant conditions. These include a lot of marine invertebrates, who live in aquatic conditions that fluctuate very little, so they don’t have to seek out heat or cooling sources. Their body temperature matches that of the surrounding water. 

• So after learning all of this about ectotherms and endotherms, you might be wondering why organisms need to regulate their body temperature? Well the simple answer is that they would die if they didn’t. When cells are as cold as water’s freezing point crystals will form inside of them, which will most likely cause the cells membrane to rupture. On the other side, when the body gets too hot (above 104 degrees Fahrenheit)...

Welcome to My AP Biology Thoughts podcast, my name is Corrinna and I am your host for episode 24 called Unit 8 Ecology: Autotrophs, Heterotrophs, and Chemotrophs.  Today we will be discussing the differences between autotrophs, heterotrophs, and chemotrophs.

• Autotrophs, heterotrophs, and chemotrophs are organisms who obtain energy in different ways. Autotrophs create their own energy. The word autotroph comes from the root words auto which means self and trough which means food. Most autotrophs use the process of photosynthesis to make their food. This process creates sugars from carbon dioxide and sunlight. Autotrophs are also called producers because they provide oxygen and a food source for animals who are in higher trophic levels. Autotrophs form the base of ecosystems’ energy pyramid since they are eaten by herbivores.
• Herbivores are a type of heterotroph. Heterotrophs are organisms that consume other organisms in order to obtain energy because they cannot create their own food. There are multiple kinds of heterotrophs. Herbivores eat plants to obtain energy and are also called primary consumers because they eat the autotrophs, who are the lowest trophic level in a given ecosystem. Carnivores consume meat from other organisms. They are usually predators and can also be secondary and tertiary consumers. Secondary consumers eat herbivores and tertiary consumers eat other carnivores. Carnivores can also be scavengers, which are organisms that eat animals that are already dead.
• Chemotrophs can be either autotrophs or heterotrophs. They obtain their energy by the oxidation of electron donors in their environments. This means that they take electrons from available molecules and add oxygen to them to form other molecules for energy. Chemoautotrophs can synthesize their own organic molecules (include auto because they make their own energy). Chemoheterotrophs obtain energy by ingesting preformed carbon molecules since they can’t make their own.

• Some examples of autotrophs are most plants, phytoplankton, and some bacteria. All of these organisms create their own food. The majority of animals are heterotrophs. Deer, rabbits, and some bird species are examples of herbivores because their food source comes only from plants. Lions, snakes, and sharks are examples of carnivores because they get their energy from hunting and consuming other organisms. Bears, dogs, and humans are all omnivores because they eat both plant and animal matter. Scavengers include raccoons and turkey vultures, who usually eat other decaying animals. 
• Some examples of chemotrophs are some types of bacteria and fungi (but not all bacteria and not all fungi are chemotrophs). These organisms require carbon to survive and reproduce. Because they most often live in hostile environments such as deep sea vents, chemotrophs aren’t as well-known as autotrophs and heterotrophs.