S7L3.a
(Explain the role of genes and chromosomes in inheriting traits)

Genes and chromosomes are the ways you inherit traits. Chromosomes carry your genes. There are 46 chromosomes in your body, or 23 pairs of chromosomes. Each parent gives you 23 chromosomes, with the egg cell carrying 23 and the sperm cell carrying the other 23. There are two forms of genes, known as alleles. Alleles are basically the different phenotype you get. For example, the gene that determines hair color comes in different alleles, like a red hair color allele, a black hair allele, and so on. Alleles can be dominant or recessive. Dominant traits appear no matter what if they are present. Recessive traits only appear if only recessive alleles are present. For example, the allele for black hair is dominant over the allele for red hair. So, if the allele for black hair is present along with the allele for red hair, black hair will be the phenotype.

S7L4.c

My opinion on genetic engineering:

Ban Genetically Modified Animals
Have you ever wondered what’s on your dinner plate? Well, believe it or not, that perfectly innocent steak lying there may be genetically modified. Sure, there are good modifications to an organism, such as removing feathers from a chicken so it can live in a tropical climate, but would you like to have pesticides in the DNA of your tomatoes? Genetically modifying organisms of the next generation can also cause pain for the parent. Even genetically modifying a plant can be very expensive. Some of these modifications are completely useless to the organism itself. Some GMs can even activate a dormant virus!

For one, genetically modifying plants can be very expensive as well as inefficient. Some scientists use a gene gun, which uses gold and tungsten. They cover the gold with gene cassettes and blast it at plant cells. For one, gold is currently 42 dollars per gram and tungsten can cost up to 250 dollars per 100 grams, meaning that modifying plants with desired traits can be fairly expensive. Both metals also have a better use in technology other than for just gene guns. Gold is used in medicines, computers, and even for space travel! Tungsten can also be used for light bulbs and steel alloys. These uses sound more useful than just inserting a single gene into a plant.

Some modifications to an animal’s genes are just useless. Tell me, why would a helpless bunny need jellyfish genes? Sure, it’s cute and all, and I would want one, but it is kind of useless. If I've learned anything it’s that when mating, animals go for the brighter colored male. Suppose these bunnies escaped into the wild. 1 month later, there’s about 2-10 glow in the dark bunnies(depending on breed). Skip forward a year or 2 later, there’s hundreds of them. This makes the bunnies more vulnerable to nocturnal predators such as owls. Sooner or later, rabbits will become extinct!

Would you like to have pesticides in the DNA of your vegetables and fruit? Sure, with normal pesticide, that stuff just washes right off. But in the very DNA of the plant? It’s everywhere! Remember, pesticides are toxic, meaning they can kill. In recent times, in India, 10,000 sheep that ate GM cotton that make its own BT-toxin pesticides died within a week of eating the cotton. Coincidence? I think not!

Just getting the genetically modified animal into the parent is a problem in itself. First the embryo must get the DNA. That isn’t so bad. But next, the mother of the GMed animal must get the embryo implanted. This can be very painful for the animal. In the US, medicines to reduce pain for the animal isn't required by law. Wait ‘till you have the animal rights groups knocking at your door….

Some GMs can activate dormant viruses. If a GM is inserted into the dormant virus, the virus may become active again. Imagine viruses that haven’t been seen or documented in hundreds of years suddenly popping up again. The human race would be doomed! Think of the plagues that spread of Europe just coming back…

In conclusion, I think that most genetic engineered traits are bad. Some can help out humanity,some are just pointless. Some GMs can just kill us all if we’re not careful. Genetic engineering is very costly, and we’re better off investing more money into advancing technology than just messing around with the natural order of things! We should leave organisms to adapt to situations on their own, not do it for them!

How do Organs Serve the Needs of Cells?
(S7L2.d)

In short, each organ has a specific task to do in an organism. For example, the digestive system breaks down food into carbohydrates, vitamins, and proteins. Without our digestive system, our cells could not use the food we eat. The circulatory system is also very important. It distributes oxygen (which is possible with the help of the respiratory system), water, and nutrients to the cells, while taking away their wastes. Our nervous system allows our body to react to anything that happens, allowing for our cells to be protected. The skeletal system protects our organs, and the cells that make them. Basically, all the organs and their systems allow the cells to do what they need.

How are Cells Organized?

(S7L2.c)

Simple. Organelle > Cell > Tissue > Organ > Organ System > Organism

And that's all of Cells/Body Systems! Hope you enjoyed the entire review!

-Jerome

Organ Systems (S7L2.e)

This was probably the longest part of Unit 2. It was easy, but the stuff we had to do for it was kind of hard. There are 9 major organ systems in the body: respiratory, circulatory, digestive, reproductive, nervous, excretory, integumentary, endocrine, skeletal, and muscular. Together, these 9 organ systems work together to keep us alive. 

Muscular System- helps you move, transports blood throughout the body, and keeps waste going through the digestive system. Organs include: smooth muscle, cardiac muscle, skeletal muscle

Skeletal System- bones support the body and protect the fragile organs within. Includes: bones, cartilage, ligaments, tendons,  bone marrow

Circulatory System (or Cardiovascular)- pumps blood throughout the body, distributing water and nutrients while taking away wastes from cells and organs. Includes: heart, blood vessels, blood, lungs, and cardiac muscle

Reproductive System (Alright alright alright! We gon learn today what a  (censor beep here) is!)- *NOTE: turn off your negative mind* responsible for allowing humans to reproduce, thus keeping our species alive. Includes: egg, sperm, testes, ovaries, penis, vagina, and prostate.

Respiratory System- intakes oxygen from the air around us while releasing carbon dioxide as waste. Includes: lungs, heart, blood, blood vessels, and bronchi.

Digestive System- breaks down food into a state that's usable for cells. Includes: stomach, esophagus, large and small intestines, and salivary glands.

Excretory System- rids the body of unneeded wastes. Includes: large intestine, sweat glands, bladder, vagina, penis

Nervous System- collects, transfers, and processes information with the brain. Includes: eyes, ears, mouth, nose, skin, taste, spinal cord, and brain.

Lymphatic System- filters the blood of wastes using the clear fluid called lymph. Includes: lymph nodes, lymph vessels, capillaries, lymph ducts, and lymph capillaries.

Endocrine System- communication for what to do within the body using hormones. Includes: pituitary gland, adrenal gland, thyroid, pineal gland, and parathyroid.

Hope you enjoyed this section of reviewing S7L2!

-Jerome

 

My cell organelle comparison poster.

Cell transport is the way a cell gets vital nutrients, water, and oxygen into itself. There's are 2 types of cell transport: active and passive transport. Passive transport happens naturally and requires no energy from the cell. Active transport, however, requires energy from the cell. I'll leave the rest to this video.
Standard: S7L4.a

Copyright: This video does not belong to me. Although the man in this video looks similar to me, I do not claim ownership of this video.

Ecology (S7L4)

S7L4. Students will examine the dependence of organisms on one another and their
environments.
a. Demonstrate in a food web that matter is transferred from one organism to another
and can recycle between organisms and their environments.
b. Explain in a food web that sunlight is the source of energy and that this energy moves
from organism to organism.
c. Recognize that changes in environmental conditions can affect the survival of both
individuals and entire species.
d. Categorize relationships between organisms that are competitive or mutually
beneficial.
e. Describe the characteristics of Earth’s major terrestrial biomes (i.e. tropical rain
forest, savannah, temperate, desert, taiga, tundra, and mountain) and aquatic
communities (i.e. freshwater, estuaries, and marine). 

This was the first unit we covered this year. We learned about biomes, relationships between animals, environmental footprint, loss of energy, and food webs. This unit took us approximately from the beginning of the year all the way to November, with learning biomes being the longest. 

The 7 major biomes of the Earth are: coniferous (also called temperate deciduous forest) forest, taiga, desert, tundra, rain forest, savanna, and grassland. Biomes can be classified in many ways. Temperature, percipitation and vegetation are two major ways biomes can be classified. 

We also learned about our ecological footprint. In other words, it's the amount of land and sea we need to sustain what we consume and our wastes on a yearly basis. Our ecological footprint also has an impact on other species living on Earth. Say everyone in the US has a high ecological footprint. That's a few million people with maybe a hundred million pounds of waste. Where does this waste go? It's not like it just flies away or anything. This can impact organisms in an environment. Take nuclear waste from a power plant for example. Doesn't nuclear radiation mutate animals? 

Food webs were another important aspect of unit 1. They display which organisms eat one another in an ecosystem. Another important part of a food web is how the amount of energy decreases as the food web goes on. This is called the 10% rule. This means that The next consumer only gains 10% of the original energy from the previous organism. For example, the producer gets 100% energy from the sun. The next organism, let's say a rabbit, eats the plant. It only gets 10% of the energy because the other 90% was used for the plant's functions. The next organism in the foodweb, let's say in this case, a wolf, eats the rabbit. It would only get 1% of the initial energy from the sun; as 90% of the 10% were used for the rabbit's functions.

The last part of unit 1 was relationships between animals. These were split into 2 types: opposition and symbiotic. Opposition is basically when 2 organisms fight for something, like for a mate. It can also be predator and prey relationships. The second kind of relationship, symbiotic, involves 2 organisms helping, in which at least 1 organism is helped out by it. The first symbiotic relationship is mutualism. Mutualism is when 2 organisms help each other out. One of the most widely known case of mutualism is between the anemone and clownfish. The clownfish helps keep away the anemone's predators, such as butterfly fish, while obtaining scraps from the anemone and being able to use the anemone has a home. The second kind of relationship is commensualism. Unlike mutualism, only 1 organism is helped, but the other one is not or helped. harmed. An example of this is a bird and a tree. The bird gets to make a nest on the tree, using it as a home, while the tree gets nothing in return. The final kind of relationship is parasitism. In this relation, one organism is helped, but the other organism is harmed. The keyword in this is parasite, or an organism that attaches itself to the host, and getting nutrients from it at the host's expense. Think of a mosquito and a person. The mosquito feeds on the person's blood, taking away oxygen and other nutrients that are vital to cells, while also possibly transferring diseases.

I hope you learned something from this review of ecology, or just remembered something small that you forgot earlier in the year.

More to come soon!

-Jerome