A Matter of Selection Blog Post #8 Annika Gordon

There are so many different types of leaves within the brassica oleracea species, you wouldn't even guess that they are all the same species.  Whether it's length, color, shape, or texture there are so many variations to look at and discover.
Some of these variations include:
purple veins

green leafs

white veins

wrinkly leaf

The biggest range from one extreme to another would most likely be the dentin of each leaf. While some leafs have little to no dentin, there are some that are up to 3 inches long.
no dentin

3 inch dentin

There are several explanations as to why traits in the brassica oleracea family vary so much. One is artificial selection, also know as selective breeding, is the process which farmers and breeders chose traits they like more than others to be continued in the genes of their plants. Different farmers probably saw different traits as being useful, and after branching off so many times you get decent with modification. It isn't all artificial selection though, natural selection also plays a role, and so do mutations. Natural selection is the random selection of genes in a plant, and mutations within the genes often occur causing the random appearance of different genes.

Though there are many differences between the plants in the brassica oleracea species, there are many similarities as well. The trait that is probably the most alike throughout all the plants is probably their color.

To get the color to change drastically, plant breeders could breed it with the purple leaves of one type of brassica oleracea plant. Though it is purple, unlike all the other plants, it is still in the same species, so breeders should be able to breed it with the green leaf plants.

A Matter of Selection-Whitley Moody

For B1.  My team and I observed all of the Brassica oleracea plants in our garden. We saw the greatest variation between the different leaves from the plants.  They were not only multiple different textures, but different colors, sizes, and smells.  We found at least ten leaves that looked completely different than the ones before them.  Below is a picture of a few examples of the leaves.

We saw the greatest range of variation in the height of the plants.  We went out into our garden and measured the height of all of our plants using a meter stick.  For being the same species, there was an extreme change from the height of the smallest fully grown plant and the largest fully grown plant.  The smallest fully grown plant had a height of 12cm, while the largest fully grown plant had a height of 72cm.  In the pictures below you can see the variety of heights displayed by the plants.  

2.  There are many reasons why there is so much variability in domestic forms of Brassica oleracea. First off, farmers have performed artificial selection and selective breeding.  Those processes allow the farmers to pick and choose which specific traits new generations of the plant will receive.  This allows them to create a new plant that might be completely different from it's mother and father plant, yet still be a part of the Brassica oleracea species.  Another way that multiple different types of Brassica oleracea have developed over time is through a process where natural variations are created.   These variations happen when mutations occur to the cells of the plants in order for them to be able to survive in their environments.  Mutations occur in the genes of the plants by deleting or adding alleles.  After both artificial selection and the process of creating natural variations happens, descent with modification will pass the genes for specific traits on to the next generation.  

3.  The part of the Brassica oleracea plants that seems to be the same in all of the examples in our garden is the fact that all of the plants originate from the Wild Cabbage plant.  Every single plant has a part that can be traced back to that plant.  I think that this happened because the species had to start with a single organism, and then it mutated and changed over time.  

-For Kohlrabi, the stem was modified from the original plant.

-For Kale, the leaves were modified from the original plant.

-For Broccoli, the stem and flower buds were modified from the original plant.

-For Brussel Sprouts, the lateral leaf buds were modified from the original plant.

-For Cabbage, the terminal leaf bud was modified from the original plant.

-For Cauliflower, the flower buds were modified from the original plant.

Clearly, all of the different plants that branch off in the Brassica oleracea species can be traced back to the Wild Cabbage plant.  Over many years, natural selection and/or artificial selection must have occurred in order for the new plants to have been made.

4. Well, since I focused on how each plant originates from the Wild Cabbage plant, in order to drastically change how each of the plants are now, plant breeders would need to continue to artificially change each new plant generation.  This would be extremely difficult because there would be a point where the plants would be unable to be engineered further.  The breeders would reach a limit on how they could change the plants.

A Matter of Selection - Maddie Gong

1. I think the one part of all the Brassica oleracea plants that shows the most variation are the leaves. We chose this part of the plants because they all have many leaves ranging in size, colors, shape and so much more. The picture below is a couple of leaves that we picked from the plants in the garden. We measured each of the leaves in centimeters. As you can see, some leaves are more green or purple, some have veins, some are wide, fat leaves while others have wrinkly, skinny ones.

The part of the plant we thought showed the greatest range of variation is the height of all the plants. We went outside and measured all of our plants with a large meter stick. In the pictures below, some of the plants are very skinny and tall while others are shorter and fatter. Although each plant grown in the garden was part of the Brassica family, they were all different kinds of edible plants such as lettuce or broccoli. Our plant (the 1st picture) was pretty tall compared to the rest but didn't have very many leaves like the other plants.

2. When it comes to plants, there are several reasons in which variation occurs. First off, farmers have performed natural selection or selective breeding. These processes are done to develop particular traits within the plant species. When species of plants are very genetically diverse, it's known as natural variation. Natural variation occurs when mutations are created within the plant cells and it's an important source of traits for plant breeding. The parent plants of some Brassica families can pass on certain traits and/or genes to the next generation of plants. This process is known as descent with modification.

3. I think the most consistent part of the all the Brassica plants is the stem. Even though each plant is sized differently between their leaves and height, they all have the same stem. If you look closely at the first picture from question #1, you can see each stem is pretty similar. Some may be skinnier or fatter than others but they all have a light green color and cylinder consistent shape. I think this is one of the only similar parts because it's the base of all the Brassica plants. The stem is the base of all the Brassica family plants.

4. Plant breeders would have to find a way to mutate and artificially change the Brassica plant stems to change it or breed it with another family of plants. I think this would be difficult because it's hard to alter a species of plants and mutating can only go so far.

Blog Post #8

Question #1
The characteristic that I noticed had the greatest variation with in the brassica plants in the garden with leaves. For example,  the length and width of each of the different plants leaves all had very different forms.  All of these leaves are very different in their length and width.





The characteristic that I found to have the greatest range was the height of all the the different brassica plants.  These pictures show 5 different brassica plants with a range of height of 28 inches- 10 inches.




Question #2
There is so much variability in the traits of domesticated Brassica because of selective breeding over several generations. Selective breeding or artificial selection, is where a person over several hundreds or thousands of years chooses the natural variations from each plant and only lets these plants germinate. The changes that each plant obtains over time represents descent with modification. This means that mutations  that are favored become most common genes in the gene pool



Question #3

Out of all of the brassica plants in the garden, they all shared one charicertics, their flowers. I believe this because for organisms to be considered a species they have to be able to reproduce and flowers on plants contain their reproductive parts. So, if they have the same looking parts that means they would fit together to breed together. This would make it easier to recognize who they can mate with and identify the same species.

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Question #4
In order for plant breeders to change the plants flowers, they would need to alter their DNA. Since all of the plants their species(aka the only plants they can breed with) have the same yellow small flowers, there is no way to cross breed it and make it different. 

Blog Post #7 - Maddie Gong

In these past few weeks, my group and I have been learning about the reproductive process in Brassica Oleracea plants. First, we researched the functions of all the main, important parts of the flower. The two main reproductive organs are the stamen (male) and pistil (female). On the end of a stamen are the anthers. The anthers are responsible for producing pollen through meiosis. Reproduction can't take place unless pollen travels through the plants. So, the pollen starts to move its way towards the stigma. Here, the pollen sticks onto the stigma. The stigma is the end of the pistil, or the female reproductive organ. Once the pollen reaches the stigma, it's taken through the pistil to the ovary. When it's in the ovary, the pollen germinates the ovules and the reproduction cycle begins.

This is a picture of the flower my partner and I chose from the garden. This is what a brassica flower looks like. Here you can see some of the main parts of the flower including the petals, stigma, anthers and the stamen.

We removed all of the petals on the flower to see the parts clearly. Here's a close picture of the stamen and anthers. The stamen is the green stem which is the male reproductive organ. The anther is the part in which pollen is created during Meiosis. Eventually, the pollen created on the anthers will reach the female reproductive organ and the plant can reproduce. The filament is the long stalk like thing on the male reproductive organ. 

 Here is a photo of the female reproductive organs. The female parts consist of the pistil. The larger end of the pistil is known as the stigma. The stigma is the sticky part of the stem where the pollen from the stamen sticks onto and gets germinated. This is how the reproductive cycle starts.

After examining the male and female parts, we removed all of the parts until we got to the insides. This small, skinny green bean looking part is the ovary. We sliced open the ovary and inside saw the ovules. The ovules are the unfertilized plants that will eventually start to reproduce. The pollen from the stamen will eventually reach the ovary and start the reproductive cycle.

Extra : We took the anthers and tapped some pollen onto a wet glass slide. We placed it under a compound light microscope and this is a close up view of it. 

Whitley Moody: Blog Post #7

          My Story of the Seed group and I have been examining the reproductive process in the flowers created on one of the species of Brassica Oleracea plants.  We have researched how the parts of the plant are being fertilized in order to reproduce.  We learned of a few important reproductive organs in our flowers.  The stamen is the male reproductive organ and the pistil is the female reproductive organ.  It all starts at the stamen of the flower.  At the end of the stamen is an anther.  On the anther pollen is created through Meiosis.  In order for reproduction to happen, the pollen made on the anther must find its way to the stigma.  The stigma is the sticky end to the pistil which is the female reproductive organ of the flower.  After the pollen has reached the stigma it is taken through the stalk of the pistil to the ovary at the base of the pistil.  In the ovary the pollen germinates the ovules where the reproduction process begins.

Here is a picture of the whole flower we took from a species of Brassica Oleracea.  You can see all petals, the anthers, the stamen, the stigma, and the top of the pistil.  The ovary is hidden because it is at the bottom of the pistil(female reproductive organ). 

This is a close up photo of the male reproductive anatomy of the flower.   This part of the flower is called the stamen.  The end of the stalk is called an anther.  The anther is where the pollen is created through Meiosis.  The pollen created on the end of the anther is the pollen that will eventually reach the female organ of the plant so that the plant can reproduce.  The long stalk on the male reproductive organ is called the filament.

This is a close up of the female reproductive anatomy of the flower.   This is called the pistil.  As seen in the photo, the end of the pistil is larger than the rest of the stalk.  That part is the stigma. The stigma is sticky.  This allows the pollen from the stamen (male reproductive anatomy of the flower) to stick where it can germinate the female reproductive organ which starts the reproductive cycle.  There are many ways for the pollen to reach the stigma.  For example, wind can blow the pollen from the stamen to the stigma. 

Here is a close up of the flower that has been completely stripped of all parts except the ovary.  I have opened up the ovary to get a clear view of the ovules.  The ovules are the tiny unfertilized green pea-like shapes.  This is where the pollen from the stamen will eventually go to start the reproductive process.

EXTRA:

This is a magnified view of the pollen taken from one of the anthers.  Done using a wet mount slide of pollen and a compound light microscope.

Blog Post #7 -Annika Gordon

These are the flowers I picked to view under the microscope to look at the parts of a flower up close. Out of these flowers my partner, Christina, and I chose just one, but ended up needing several as we messed several times. We made sure to pick flowers with larger anthers and pistils so that we would be able to see all the different parts more clearly than on small anthers and stigmas.

This image is of the anthers, which is part of the stamen, the male anatomy of a flower. It surrounds the pistils showing that this particular flower is both male and female, whereas some are just male or just female. The anthers grow at the end of stamen and consist of a sac which produces and releases pollen. This pollen is then picked up by birds, bees, and other insects on their bellies and feet when they land and transferred to the stigma of neighboring flowers.

This picture is of the the female anatomy of the flower, the carpel also know as the pistil, which contains the stigma, style, and ovary. The stigma is the sticky top which pollen grains attach to, and could be considered the landing zone for these pollen grains. The style is a long stalk which connects the stigma and ovary allowing the pollen that lands on the stigma to transfer sperm cells down into the ovary. In the ovary ovules are produced which when fertilized by sperm cells eventually become seed allowing for the flower species to continue living.

These are images of the inside of the pistil, more specifically the inside of the ovary which was cut in half so we could understand what was inside. The little round balls, more obvious in picture two, are unfertilized ovules. When they aren't underneath a microscope, they are smaller than even a grain of rice, but are the reason plants can reproduce. Without ovules the sperm cells from the pollen wouldn't have anything to fertilize, marking the end of that plant species life.

This image shows a very close up view of the pollen found on the anthers of our flowers which is used as a "capsule" for sperm cells. Pollen is grown on the anthers of plants and when picked up by wind or insects are transferred to the stigma of another plant. This picture is taken from a light microscope where we zoomed in so much you could see little ridges all over in, but the picture didn't capture them, so in reality pollen is actually smaller than even a grain of sand, yet it might just hold more importance.