Perfect Paragraph - Durfee Conservatory / Camellia House

Submitted by kcapri on Thu, 02/09/2017 - 23:56

I’ve learned that camellias are usually very small trees or shrubs. They have flowers that can be various colors and sizes. These trees can bloom in late fall, winter, or early spring. There are two species of camellias - Camellia japonica and Camellia sasanqua. The trees in the Durfee Conservatory are classified as Camellia japonica. They bloom in the winter and have brillant pink and white flowers. I learned that a certain camellia tree, C. sinensis, has leaves that are used for tea.

Journal #3: Rhodesian Ridgeback

Submitted by astaubin on Thu, 02/09/2017 - 23:21

A Rhodesian ridgeback, which are also well known as “lion hunters.” Rhodesian Ridgebacks are a breed of dog, that were bred specifically to hunt lions and chase them up trees in Africa. Ava’s fur is a short tan/brown color. Along her back, she has what is called a ridge. It is a long cowlick that goes along her back and looks like a Nike symbol. Her body is long, and skinny and she stands very tall. On her chest she has a large white patch, with tan spots. The color on her face is much different than the color on the rest of her body. Her snout is black and fades to a tan color. The black starts to fade back in around her eyes and has a black ring of fur around them. Her ears are short but kind of hang off her face. They also fade to from her tan to back as you look at the tips of ears. Her eyes are golden and resemble the color of honey. Watching her look out the window, you can see how shinny her eyes are. She also has a long tail, which seems to also transition to black the closer you get to the tail. 

Journal #2: The Greenhouse

Submitted by astaubin on Thu, 02/09/2017 - 23:20

Trying to find a type of moss that showed the gametophyte and the sporophyte was kind of difficult but finding it lead me to a super cool place, the UMass Greenhouse which I have never been before. I walked in; it was like a sea of green. I enjoyed looking at all the different plants. The first room I walked into I noticed a wide variety of bonsai trees. Then I walked into the next room, which had a small pond, but was much warmer than the room I was just in. It had a wide variety of different plants that need a warmer climate to grow.  The greenhouse had many different places to sit and enjoy the scenery. I looked at many different plants, which made stop and enjoy what they do for our planet and how important they are. After enjoying the greenhouse for quite sometime, I left to get pictures of the moss. I began by taking pictures of moss that seemed to growing on the base of a small shrub. It was bright green and the sporophytes that were growing, looked like miniature plants growing. If you didn’t know anything about moss, you might have confused the sporophytes for seedlings, which at first was what I thought. After taking several different pictures, I noticed that the moss at the base of the plant needs the plant that it lives on to survive and forms this unique symbiotic relationship. 

Journal #1: Moss

Submitted by astaubin on Thu, 02/09/2017 - 23:19

As I was wondering along campus, I was trying really hard to find a patch of moss that had signs of gametophytes and sporophytes. As I was taking pictures of the different kinds of moss, I really wanted more information and research on the life cycle of moss. I also wanted to know what the key differences were between a gametophyte and a sporophyte. The gametophyte is always haploid, and only has one set of chromosomes.  The gametophyte then goes through mitosis, and produces both male and female gametes. The gametophyte has different organs where the gametes are produced. The organs are called Archegonia, which makes the egg cells. The Antheridia produces the spermatozoids.   The fusion of the male and female gametes further produces a diploid zygote, which is what we refer to as the sporophyte. The sporophyte usually grows on top of the green gametophyte. In order to stay alive, the sporophyte is nourished by the gametophyte. In the capsules in the top of the sporophyte usually grows and develops the spores. When the capsule is ready, it will open and free the spores. Also, I learned that depending on the type of moss, the sporophytes would look different. Another thing that I found interesting about moss is that it doesn’t have vascular tissue. The vascular tissue is used to transport water and nutrients throughout the plant. Due to this, moss actually lack roots, a stem and flowers. 

Action potentials

Submitted by jdantonio on Thu, 02/09/2017 - 22:58

Neurons are the cells responsible to transmitting information throughout the body. They accomplish this through both electrical and chemical signalling. The way a neuron conducts a signal within itself is electrically, charged ions travel down the length of cell and stimulate a chemical release from the axon terminal. This electrical signal is known as an action potential and is one of the most important physiological mechanisms of the nervous system.

An action potential is generated by the depolarization of the resting membrane potential of a neuron, which is about -65 mV. This resting potential is created by the careful regulation of intracellular and extracellular fluid ion composition. Electrochemical gradients are created by this regulation that are critical for an action potential occurrence. These gradients are achieved by both ATP dependent ionic pumps and membrane impermeability.

An action potential begins when some stimuli causes the opening of Na+ channels in the axon hillock which changes membrane permeability and allows Na+ ions to flow into the cell with the gradient that was created while the cell was at rest. This depolirizes the neuron and makes the membrane potential more positive. If the stimuli is strong enough then enough NA+ will enter the cell to raise the membrane potential to -40 mV, this is known as the threshold for an action potential. If this critical value is met then additional Na+ channels open, these channels which are regulated by the voltage across the membrane are known as Voltage-gated ion channels. This additional Na+ entering the cell further depolarizes the cell raing the membrane potential to 40 mV.

However depolarization lasts for only a brief moment for the voltage-gated Na+ only open for approximately 1 ms and an additional channel opens called a K+ voltage -gated ion channel which allows K+ to flow out of the cell with its own chemical gradient. This process of ending the influx of Na+ and causing the efflux of K+ is called the repolarization phase of an action potential. The membrane potential becomes more negative as there is a net flow of positive ions out of the cell, this continues until the membrane potential is even lower than resting in what is called the hyperpolarization phase of an action potential. This stage is critical as it prevents messages from being sent bidirectionally in the cell. The Na+ and K+ pump proteins then restore the membrane potential to its normal resting potential as K+ voltage gated channels close. This process occurs sequentially starting with the axon hillock and moving down towards the axon terminal each section of membrane that is depolarized stimulates the depolarization of the next section down the line. In this way the message that was caused by the original stimuli is passed through the neuron electrically.

 

Source

 

Bear, M. F., Connors, B. W., & Paradiso, M. A. (2007). Neuroscience: Exploring the brain. Philadelphia, PA: Lippincott Williams & Wilkins.

 

Stanfield, C. L. (2013). Principles of Human Physiology: Pearson New International Edition. Harlow: Pearson.

Western Yellow Pine Tree Observations

Submitted by jgirgis on Thu, 02/09/2017 - 22:51

Today, I visited the Durfee Conservatory. The first observation that was made was that there was an exuberant amount of greenery: plants in pots and on the wall, trees everywhere, etc. Directly on my left was a Western Yellow Pine tree. The tree was located on a bed of rocks that were different shades of brown; some rocks were light brown, while others were dark brown. Furthermore, the pine tree was growing in soil that had moss growing on it. The moss did not encapsulate the entire soil, but instead was growing solely on the edges of the pot. Additionally, the trunk of the pine tree was growing in a spiral manner. The trunk itself was a light grey color at the bottom. However, the top of the trunk was a dark brown color. Also, the tree only had three branches, which is where the pine was growing off of. The pine was green and about four inches long. It was growing in a spiral manner, following the shape of the trunk.

Octopus perfect paragraph

Submitted by amprovost on Thu, 02/09/2017 - 21:37

A new species of octupus has recently been discovered off the coast of Hawaii. This species is a small, near transparent animal nicknamed Casper, after the famous cartoon ghost. This species occupies a relatively small environment, dwelling about 3 miles below sea level in a small area off of the coast of Hawaii. This new species lays eggs that take about three years to hatch. There is much concern that this species may soon be endangered by a new form of techonology: deep sea mining.

Questions I had in my bio course reading

Submitted by jiadam on Thu, 02/09/2017 - 21:19

When the receptor interacts with the ligand to create a response, can this response promote an action as well as prevent an action from happening? I would assume this to be true seeing there is no specific "action" stated.

After there is a change in metabolic activity and gene expression, how would the kinase be told to stop? What are the measures put in place that allow the cell to limit over expression and what are the consequences when over expression does occur?

If the law of homeostasis applies in every situation and in every process, how does a cancerous cell continue to proliferate and does not cease to stop. Does the cancerous cell not obey the law of homeostasis?

Do G proteins not diffuse far from the receptor that activated them because non-polar molecules like to clump together in aqueous solutions? They would likely stay close to each other rather than further away.

Can a mutation that cause the second messengers to have longer lifetimes and slower degradation cause cancerous cells? The cell in theory would over express the signal transduction pathway which would lead to cellular complications.

In essence, phosphotase is the reverse reaction to the kinase which phoshorylates. Does one phosphotase reverse protein kinase A or does it require numerous proteins? Does the amount of phosphotase depend on the speed, strength, and duration of a signaling event?

If two tyrosine kinase domains were ot able to autophosphorylate each other, how would this affect the substrate binding?

When a kinase is constantly actively promoting growth and division even in the absence of a growth factor, is this due to a constant positive feedback loop? If there is in fact a a kinase in a constantly active state promoting growth without a growth factor, does this mean the transduction pathway can skip steps and start proliferating more cells at a later step in the process?

Journal Entry #2- Independent Study

Submitted by maurabenson on Thu, 02/09/2017 - 19:26

 

I work in a biology lab on campus, where we are looking at rod cells in eyes of zebrafish. Just like in human eyes, there are two different types of photoreceptors in the eyes of zebra fish: rods and cones. Both of which make up the area at the very back of the eye where light is shined to when we see through our eyes like lenses. There are more rod cells than cones, and they detect changes in light and darkness as well as allow us see shapes, movement, and depth. Rods contain the pigment rhodopsin which allows people to see in low light conditions. Cones, on the other hand are more sensitive to colors and only really are active in areas of bright light. Cones are also responsible for seeing fine details. Once the information is recieved by the rod and cone cells, it is translated to the optic nerve which allows us to see. 

Over the last year, an experiment was done in the lab by a post-doctoral student where they ran a chemical screen on zebrafish to see how different chemicals and inhibitors affected the growth and shedding of the outer segments of rod cells. They investigated this because it is known that the rods do grow and shed, but there is no molecular mechanism for this discovered yet. Also, when rods shed too much and do not grow fast enough, the rod dies and they do not regenerate which causes blindness. Seeing if any certain chemicals can inhibit shedding or increase growing can help lead to medicines that can decrease blindness. Being only a sophomore on this project, I was given the responsibility of data collection, so I sat on the computer and measured the growth of the cells from images taken on confocal mircoscopes.

Now, as a junior in the honors college, I am currently beginning the research that I will do my thesis on, where we will be taking different chemicals in the screen and doing a dosage compensation for them, to see how different amounts of the chemicals affect the shedding and growth. We are in the early phases now by first breeding the zebrafish. We first paired the fish off with 2 females and 2 males in smaller tanks. We kept them divided so we could strat the breeding process the next morning so we would know how old the eggs were and they would all be the same age. When we pulled the divider, we also raised the tank so there was a shallower end. This is beacaus the fish instinctually lay in shallower water. After collecting the eggs, we sort out the viable ones and incubate them. That is as far as we have gotten thus far, but the semster has just begun. I am looking forward to the progress we make! 

Dogs

Submitted by scestero on Thu, 02/09/2017 - 17:09

Nala is your typical black and white siberian husky. She has bright blue eyes that pop out because it looks like she has a thick black eyeliner on. Her fur is very thick and straight. One thing i noticed about her was the black fur, when you push around the black hairs they reveal the white bottom to them. The curious thing about this is that there is no white to black transition. Her tail curls up and makes an arch that touches her back. The inner arch of her tail is black while the outer arch is white. Finally, Nala is a medium sized slim dog, with skinny legs. The bulldog on the contrast is short with stubby legs. He is white with patches of brown fur all aorund it. Unlike Nala, the bulldog seems to have rolls of skin on his back and neck. The bulldog also has a short stubby tail. 

 

 

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