THE EARTH HAS SLOPE, GRADIENT, AND TOPOGRAPHY
In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line.
Topography is the study of the shape and features of land surfaces.
THe structures of the land create different environments
Creatures can fill different ecological niches within a biome.
There will be differences in temperature, salinity, pH, and more.
An example of a creature that lives in a very specific environment is the axolotl in the Anahuac Valley, now Mexico City.
Axolotl live in brackish (semi salty) water in Xochimilco and Lake Texcoco in Mexico City, they are very endangered. They eat mollusks, worms, insect larvae, crustaceans, and some fish.
There are 17 different species of Axolotl, locally they are called achoque, they are salamanders. Salamanders are a type of amphibian, creatures that have an aquatic gill-breathing larval stage followed (typically) by a terrestrial lung-breathing adult stage.
Salamanders stay in water more but they may breathe through their skin or develop lungs. Axolotls stay in the water and don't go through metamorphosis, they develop functional lungs, but retain gills and generally use them to breathe.
There are restoration efforts that help protect the Axolotl.
They only live in one place
Their home went from being a lake, to becoming the Mexica City of Tenochtitlan in 1325, to becoming one of the biggest cities in the world after the lake was drained. There are currently still aquifers under Mexico City and the people drink this aquifer water, so the city is sinking.
MEXICO CITY DURING AZTEC (Mexica) TIMES, YEARS 1324-1430
It was a tricky place to grow food:
Lake Chalco and Lake Xochimilco to the south were freshwater lakes, lakes to the north, Tetzcoco, Xaltocan and Zumpango, were salty.
Axolotl adapted to changing levels of salinity, when floods moved water from salty areas to freshwater areas, many plants and animals would die. There are also aquifers, underground water ways, that feed the lakes.
To overcome the problems of drinking water, Aztec (Mexica or Tenochca Mexica) engineers built a system of dams to separate the salty waters of the lake from the rain water of the effluents.
Aztec (Mexica) communities grew food on Chinampas, strips of land that were made from the fertile soil from the bottom of the lake. They were artificial islands.
People in this region spoke Nahuatl, it is still spoken by about 1.7 million people today. The people in this region identified as Mexica or Tenochca Mexica, not as Aztec.
Spanish COnquerors drained the lakes
When Spanish Conquistadors went to what is now Mexico City, they destroyed as much of the city as they could and drained the lakes to build a new city on top of the existing city.
This video shows us why and how the region is slowly sinking:
Efforts to protect Axolotl
This conservation effort involves making cough syrup with them :(, you win some, you lose some. Axolotls are very important in medicine, we will learn more about that soon.
Another threat to rivers and lakes is eutrophication, when fertilizers are washed off the land and into the bodies of water.
When there are too many nutrients in a lake or other body of water, generally because of runoff from the land. Excess nutrients cause a dense growth of plant life and death of animal life from lack of oxygen.
The area where the axolotl lives is their habitat, the habitat is part of a biome
A biome includes many habitats and many ecosystems.
A biome may be an ocean, grassland, a forest, a tundra, rainforest, desert.
The Marine Biome covers about 70% of the Earth's surface and is home to more than 230 thousand known species. Marine plants provide over half of the oxygen on Earth. There are separate biomes within the ocean based on depth, temperature, and biodiversity. A coral reef is a biome. Within the coral reef there are different habitats and niches.
Rivers streams, ponds and lakes, and wetlands are fresh water biomes.
Polar regions have tundras, there are less plants, animals need to get food from the ocean or hunt other creatures.
Forests may be full of evergreen trees in colder areas.
Tropical Rainforests get more moisture and humidity, they are close to the equator and are warm, full of life. Important producers of oxygen and many medicinal plants have been discovered there.
A savannah or grassland has low growing plants like grass and flowers.
Deserts are dry, may be hot or cold, very little rain, may drop to below freezing at night and be very hot during the day. Have cacti, grasses, shrubs, some trees.
People are reflecting on the lack of regard for the environment and are speaking up
Greta Thunberg is a Swedish environmental activist who is internationally known for challenging world leaders to take immediate action against climate change.
She was diagnosed with Asperger syndrome/ Autism, obsessive–compulsive disorder (OCD), and selective mutism.
In one of her first speeches demanding climate action, Thunberg described the selective mutism aspect of her condition as meaning she "only speaks when necessary." She is now 18 years old.
Welcome back to school, this is Biology semester Two
This week we are learning about how animals and plants interact with each other and survive in their environment. This part of biology is known as population ecology.
The study of ecology includes:
Types of migrations, genetic exchange, and forms of symbiosis population distribution patterns, food chains, population growth pattern, why we need pollinators, and how species spread.
An ecosystem involves all living and non-living components in an area, how energy flows and matter cycles through an environment.
Atmosphere: this includes the wind speed and direction, humidity, light intensity and quality, precipitation and temperature.â
Biotic Factors: These are all the living organisms in the environment, including their interactions.
âAbiotic factors: elements that are not alive: soil, rocks, mountains, rain, clouds
Living organisms interact with each other in their habitat, they influence matter by walking around and moving things around.
Habitat: the natural environment in which a creature lives including the biotic and abiotic factors.
Each organism occupies a niche, an ecological niche of an organism is their function in the ecosystem: where they live, what organisms they interact with, how they respond t changes in the health of the environment.
Tolerance rage: each species has a tolerance range, this is their comfort zone, at what point they move to another environment.
What is pH and why does it matter?
The term pH refers to the acidity or alkalinity of a solution, it stands for potential hydrogen.
Substance that release hydrogen ions when dissolved in water are acids.
The more hydrogen ions they release the more acidic they are.
Substances that release hydroxide ions when dissolved in water are bases.
Alkalinity increases with the concentration of hydroxyl ions.
Each pH unit represents a 10-fold change in concentration.
Contaminants CONTRIBUTE to Acid Rain
Acid rain: rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids. -Oxford
Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic.
However, when rain combines with sulfur dioxide or nitrogen oxides produced from power plants and automobiles the rain becomes much more acidic. Typical acid rain has a pH value of 4.0.
ph and Environmentalism
In general, fish reproduction is affected at pH levels below 5.0
Fish begin to die when pH falls below 4.0
A pH change of 1 means a ten fold change in the ions.
pH 9 is ten times more basic than pH 8
pH stands for potential of hydrogen, a measurement of the acidity or alkalinity of a solution
7 is neutral
1 to 6 are acids, 8 to 14 are bases
Acids are substance that break apart in water to form a hydrogen ion.
Acids react with carbonates to give off carbon dioxide
Bases are substances that break down in water and form hydroxide ions (OH-).
The greater the concentration of OH- ions the stronger the base is.
Have a pH from 8 to 14
pH 9 is ten times more basic than pH 8
Interesting ph facts
âSome plants tell us the pH of their soil by expressing different colors of flowers.
Venom is Acidic
A sting from a bee may be painful for many reasons, pH of bee venom is 5.0-5.5
Formic acid in ants has a pH of 2 to 3
The pH of a river is not the same as the pH of the rain
When it rains or we use water for irrigation, water goes downhill, down the gradient of the earth
There is a connection between the water that moves across land and the pH of bodies of water such as lakes, rives, ponds, and the seaâ
Water moves through a watershed, the way the surface water drains down from ridges to basins.
coral Reef Health
Through this class we will learn to describe how environmental change affects the ecosystem of a coral reef and explain what coral bleaching is.
We may then practice our language skills by reading an article, participating in a class presentation, and writing down an explanation of coral bleaching.
Please write down an example of energy transfer
Examples of energy transfer in biology:
Food web or trophic levels, sound waves, electrical currents in electric eels, photosynthesis,
Sound Wave Energy Transfer
Review what coral is
Please read the following article:
Who lives there?
Coral Reef Food Web:
WHat is coral bleaching?
Bleaching occurs when warm ocean water stresses corals to the point that they expel the tiny algae, known as zooxanthellae, that normally live inside their tissues. The algae provide the corals with most of their food, as well as their color. If the heat stress is lessened soon enough, the coral can recover.
Please write an explanation for coral bleaching using the information from class.
From the deep sea to the seashore
The average ocean depth is 2.3 miles, or 12,100 feet, or
3,688 meters, most of the hydrothermal vents that have been studied have been more than 2000 meters below the surface of the ocean.
These are some modern day deep sea creatures:
Geological TIme Scale
The source of genetic diversity is a mystery
It is possible that fungal spores came from space on an asteroid or meteor, fungi spores are able to survive in the vacuum of space. The fungi were possibly eaten by Earth creatures and more genetic code was introduced.
Insects and fellow land dwelling arthropods, crustaceans, and annelids
Worms are annelids, they don't have a backbone, and have many segments, no legs, and have been on land Earth about 500 million years. Worms started their existence in the ocean, the polychaetes are sea worms.
Sea Scorpions might have been the first creatures to leave the ocean and adapt to land about 500 million years ago.
Eurypterid scorpions, they had chitin as a protein.
Ancient crustaceans, sanctacaris, seem to be related to scorpions and then much later, spiders.
About 420 million years ago during the Devonian period we see land dwelling millipedes, they are some of the first land dwelling creatures along with centipedes, pillbugs/ rollie pollies (the only land dwelling crustaceans), and scorpions.
380 million years ago
Ants are part of the order hymenoptera and are thought to have evolved about 210-160 million years ago before blooming plants, there are ants preserved in amber that are 190 million years old.
At that time there were coniferous trees, the gymnosperms, which are wind pollinated. There were wasps before bees, though both are part of hymenoptera.
Plants with flowers, the angiosperms, were first seen during the Cretaceous Period about 145 million years ago.
This is when bees, moths, and butterflies emerged, moths are seen in fossil records first, more butterflies are seen during the Eocene Period about 40 million years ago.
Cambrian explosion and Extinction
Cambrian Extinction was about 488 million years ago, there have been many mass extinctions
Interesting Ancient creatures:
Trilobites: survived about 4 mass extinctions:
Trilobites used chitin as a protein, just like mushrooms, the shell was chitin and calcite
Ostracoderms: armoured, jawless, fishlikevertebrates that emerged during the early part of the Paleozoic Era (542–251 million years ago)
Late Cambrian times had eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms
When plants got bigger and absorbed more Carbon Dioxide, there was an Ice Age
Devonian period was 419 million years ago (mya), there were Devonian Forests 360 mya
A 375-million-year old fossil. Tiktaalik roseae, better known as the "fishapod," is a 375 million year old fossil fish which was discovered in the Canadian Arctic in 2004.
Bones that show the beginning of legs
During the permian period 298 million years ago, we see stem mammals:
Dimetrodon is a stem mammal, they have teeth that look more like canines.
Permian-Tirassic Extiction: 252 million years ago
Chicxulub crater after impact, 66 million years ago, the meteor is thought to have been over 9 miles wide
Mammal- Like Reptiles (stem mammals) learned to burrow and fill ecological niches
Synapsids were transitional animals that began to behave more like mammals and survived the mass extinction that killed many large reptiles.
Land masses are part of tectonic plates that move and form different patterns, there was a time when animals could walk from modern day Australia to Canada without worrying about an ocean being in the way.
Each Era has Periods and Epochs:
today's Sea to Land transition
The shores of the Earth have coral reefs:
The red areas are coral reef zones
Coral Reef ecosystems are at risk of being destroyed and many scientists are working to make things better
Another ecosystem seen along shores: Mangroves
World map that shows where mangroves live:
Mangroves are torn down for agriculture and shrimp farming, when the mangrove forests are destroyed, there is more land erosion and destruction of property for people along the coast, there are people working on preservation and restoration of these vital ecosystems.
WHat is the oldest Species on the planet?
The Sea Sponge from Phylum Porifera
Another ANcient Creature is The Comb Jellie
ctenophora: Comb jellie, not quite a jellyfish: Ctenophora comprise a phylum of invertebrate animals that live in marine waters worldwide. They are notable for the groups of cilia they use for swimming, and they are the largest animals to swim with the help of cilia.
Cnidaria: Cnidaria is a phylum containing over 10,000 species of animals found exclusively in aquatic environments: they are a predominantly marine species
Jellyfish Biology: fertilized jellyfish eggs develop into larval planulae, they become polyps, bud into ephyrae and then transform into adult medusae.
Coral Biology: Although many corals resemble plants, they are actually members of the animal phylum Cnidaria. Most corals are colonial, which means that each coral is made up of many individual polyps connected by living tissue (the coenosarc).
The first coral reefs date from the early Ordovician of about 500 million years ago, and their form at the time differed significantly from that of corals today, which, following, the mass extinction 240 million years ago at the end of the Permian period, first appeared in the middle of the Triassic period.
Brachiopods are marine animals belonging to their own phylum, Brachiopoda, of the animal kingdom. Modern brachiopods occupy a variety of sea-bed habitats ranging from the Tropics to the cold waters of the Arctic and, especially, Antarctic.
Geologic Time Scale
Today We get to see ancient fossils
The science of naming, describing and classifying organisms and includes all plants, animals and microorganisms of the world.
Every species is organized by Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.
The three Domains are Bacteria, Eukaryota, and Archaea
Bacteria are prokaryotes, they do not have a nucleus
Eukaryotes have a nucleus, this group includes plants, animals, fungi, and many single celled eukaryotes
Archaea are very ancient, some live in environments that few living beings can thrive in
Are about 3.5 billion years old, calcareous mound built up of layers of lime-secreting cyanobacteria and trapped sediment, found in Precambrian rocks as the earliest known fossils, and still being formed in lagoons in Australasia.
Cyanobacteria are very ancient life forms, perhaps only Archaea are older.
The use of radioactive isotopes as a measure for determining the age of a rock or fossil
An unstable form of an element that decays into another element by radiation, that is, by emitting energetic particles
The amount of time it takes for one half of a substance to decay
Has a half life of 4.5 billion years
Has a half life of 1.3 billion years
Types of life
Found to have existed 3.5 billion years ago, a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles.
Prokaryotes include the bacteria and cyanobacteria.
Bacteria and Archaea are prokaryotes
Bateria may have:
whip-like appendages used to move around, like arms
short, hair-like appendages extending from the surface, used to stick to surfaces
sticky coating, used to stick to surfaces
Types of bacteria
are a phylum of bacteria that obtain their energy through photosynthesis and are the only photosynthetic prokaryotes able to produce oxygen.
are referred to as cocci (singular: coccus),
an example is Streptococcus
Cylindrical, capsule-shaped bacteria
are named bacilli (singular: bacillus), bacteria that make yogurt: Lactobacillus bulgaricus
are called spirilla (singular: spirillum) Lyme disease and syphillis are caused by this type of bacteria
Cell division in prokaryotes is called binary fission, asexual reproduction by a separation of the body into two new bodies, cells transfer genetic information by making contact.
Both Archaea and Bacteria can reproduce through binary fission.
are all bacteria bad?
Some but not all bacteria are pathogens: a disease causing agent
Some bacteria are purely beneficial and help with symbiosis: the relationship in which two different organisms live together, often interdependently.
Converting atmospheric nitrogen into a form that plants can use to grow
The other domain of prokaryotic life, tend to live in extreme environments
Grouped according to where they live (pg 371):
Some Archaea live in hydrothermal vents
In deep sea vents, heated fluids rise to the surface through openings in the seafloor. Hydrothermal fluid temperatures can reach 400°C (750°F) or more, but the archaea do not boil under the extreme pressure of the deep ocean.
As they pour out of a vent, the fluids encounter cold, oxygenated seawater, causing another, more rapid series of chemical reactions to occur. Sulfur and other materials precipitate, or come out of solution, to form metal-rich towers and deposits of minerals on the seafloor.
The sea floor is an anaerobic environment, no oxygen
Who lives there
It is theorized that this is where life on Earth originated
Deep sea mining might be connected to cobalt mining
Cobalt is used for phones and computer batteries, some companies are interested in mining it from the deep sea.
Alternatives to cobalt are needed so companies don't consider deep sea mining a viable option.
Most Cobalt currently comes from Democratic Republic of Congo
DR Congo produces 60% of the world's supply of cobalt. The mineral is used to produce lithium-ion batteries used to power electric cars, laptops and smartphones. However, the extraction process has been beset with concerns of illegal mining, human rights abuses and corruption.
What are alternatives to cobalt?
A good battery is able to store current and transfer it, conduct heat, and cool quickly.
Some of the methods that are used to develop Bio tech
The ancestral form of trait selection, when people intentionally breed plants and animals to have certain characteristics. When wild plants were bred into food crops.
Genetic Modification in a Lab
Genetic Engineering with Agrobaterium tumefaciens
DNA samples are studied through PCR Electrophoresis to see if the target DNA is in the sample.
Results to read
Genetic Engineering of Mosquitoes
PCR in Crime Scene Investigation
But it is not perfect
What are some possible issues with this biotech?
That applies to plants, what if we GM people?
Emmanuelle Charpentier and Jennifer Doudna have been awarded the 2020 Nobel Prize in Chemistry for their development of CRISPR/Cas9 genetic editing, this video is from 2015.
there are many ethical issues to consider
Stem Cell Organs
Biomedical Engineering includes mechanical, Biological, chemical ENGINEERING and computer software
Upcoming issues to resolve
Really, it's a very big deal
It is better to wash your hands than use hand sanitizer, otherwise, the bacteria that survive are the ones that get to pass on their genes
Chapters 11 and 12
Gregory Mendel’s research on genetics.
What is a Punnett Square and how do we use it?
Natural selection and adaptation: insects and plants adapting to chemicals, how organisms find ways to survive.
A change in the nucleotide sequence of DNA
An allele that is visible in the organism only if to copies of the allele are present
an allele that can mask the presence of a recessive allele
Having two different alleles
Having two identical alleles
The visible or measureable features of an individual.
The particular genetic makeup of an individual
Specialized reproductive cells that carry one copy of each chromosome (they are haploid)
Half the genetic information compared to most cells, one copy of every chromosome
Having two copies of every chromosome
The two copies of each chromosome in a diploid cell.
A specialized type of cell division that generated genetically unique haploid gametes
An early stage of development in which maternal and paternal chromosomes pair and physically exchange DNA segments
The principle that alleles of different genes are distributed independently of one another during meiosis
Stem Cell Technology to help Same Sex couples reproduce: In vitro Gametogenesis
A cell that is capable of developing into an adult organism.
An early stage of development reached when a zygote undergoes cell division to form a multicellular structure.
An individual who is heterozygous for a particular gene of interest, and can pass the recessive allele to offspring.
A diagram used to determine the probabilities of offspring having particular genotypes b looking at the genotypes of the parents
CRISPR (/ˈkrɪspər/) (clustered regularly interspaced short palindromic repeats)
Gene editing technology.
The 2020 Nobel Prize in Chemistry has gone to Emmanuelle Charpentier and Jennifer A. Doudna “for the development of a method for genome editing.” That method, formally known as CRISPR-Cas9 gene editing but often called simply CRISPR, allows scientists to precisely cut any strand of DNA they wish.
CF is Recessive, Huntington's Disease is Dominant
With an autosomal dominant trait, if one parent has it, the children have a 50% chance of inheriting that gene, if they have that gene, they have the trait.
Hemophilia is an inherited bleeding disorder in which the blood does not clot properly
Hemophilia is a sex-linked trait and recessive.
The recessive gene for hemophilia is carried on the X chromosome.
Males inherit one affected X chromosome from the mother and, less commonly, females inherit an affected X chromosome from both mother and father experience the disease.
Females who inherit an affected X chromosome from either mother or father are carriers for the disease.
More genetic complexities
Paired chromosomes present in both males and females; all chromosomes except the X and Y chromosomes
X Linked trait
a phenotype determined by an allele on an X chromosome
Heterozygotes have a phenotype that is intermediate between the dominant and the recessive genes.
Wavy hair is an example
Both alleles contribute equally to the phenotype
An example is Blood Type
The three blood types are A, B, and O
The possible combinations that we inherit from parent are:
OO, AO, BO, AB, AA, and BB
Both parental alleles contribute equally to the phenotype
O is recessive
So if you are blood type A, you may be AA homozygous or AO heterozygous
Different blood types have different surface markers, not every blood type is compatible:
Genes move with individuals
a change in the frequency of an allele within a population over time
As individuals move around we can observe genetic drift
Something happens leaving only a few individuals to reproduce
The new population might not fully represent the ancestral population
Tasmanian devils and population bottleneck
Author: Jazmin Gannon
A place to grow