16. Describe two evolutionary consequences if the process of crossing over in meiosis ceased to occur. If crossing over in meiosis ceased to occur there would be less genetic variations and no diversity among a species. This would essentially mean that a species would not be able to adapt to an issue that could arise in the future, meaning that its species could potentially become extinct due to climate change or other arising events.
17. Fruit flies normally have eight chromosomes. The diagram below shows the result of meiosis in three fruit flies to produce gametes with the number of chromosomes indicated. The male then mates with both female A and female B to produce three zygotes (1, 2, and 3).
a) In which parent did nondisjunction take
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Zygote 1= 7, Zygote 2= 9, Zygote 3= 9.
c) Which zygote, if any, would be most likely to be healthy? Explain. There would be no zygote that would be more likely to be healthy than the other. None of these zygotes have the normal number of chromosomes (eight).
d) Name the conditions the non-healthy zygotes have. Zygote 1 has monosomy (it has a missing chromosome); Zygote 2 and 3 has trisomy (they have an extra chromosome).
18. a) Explain the process of nondisjunction can result in an individual with Klinefelter syndrome. Create a diagram showing the disjunction occurring in the mother to help explain your answer. Individuals with Klinefelter syndrome have XXY chromosomes, and can occur when during the prophase of meiosis I, in females there is nondisjunction of X chromosomes. This results in a male with trisomy. One egg can have no X chromosomes and the other could receive both X chromosomes.
23. Agree
1. Private businesses are a business, so they should make revenue off of what they invested their money into.
2. Scientists deserve recognition, and therefore should be allowed to sell his or her creation or own the rights to it for a number of years in order for their hard work to be seen and pay
Q: 18. Do you think the mutated Fire allele fb is dominant or recessive to the existing Fire alleles F?
these are egg cells and sperms, each with a reduced or halved number of. chromosomes. The chromosomes are. The number of chromosomes is restored when two gametes fuse together to form a zygote. A cell with two copies of each. chromosome is called a diploid cell and a cell with one copy of each.
Down Syndrome results when one of the three types of abnormal cell divisions involving chromosome 21 occur. Roger W. Harms, a medical doctor, states, “Human cells normally contain twenty-three pairs of chromosomes. One pair comes from your father and one pair comes from your mother.” In each pair, one chromosome comes from the father, and one comes from the mother. One of the three genetic variations that can cause Down Syndrome is Trisomy 21. This version of Down Syndrome occurs more than 90% of the time. It re...
The type of mutation that occurs in Down syndrome is aneuploidy that is the irregular number of chromosomes in a cell. The most common of the three is the trisomy 21 that occurs in about 90% of people with the disorder. In this factor the human is given three copies of the chromosome 21 instead of the common two copies. This occurs due to the complications of the cell division in the process of the egg or sperm. The next case is mosaic which happen when there are inequality of cells with three copies of chromosome 21 and others with the original two copies. Mosaic appears when there is an unexpected cell division after fertilization. The last and the rarest form is translocation and that happens while the chromosome 21 in cell division is broken off and attached to another chromosome. Since the disorder is unexpected there are numerous amounts of risk factors that are possible based on the severity of the person.
Most cases of Down syndrome are not inherited. When the condition is caused by trisomy 21, the chromosomal abnormality occurs as a random event during the formation of reproductive cells in a parent. The abnormality usually occurs in egg cells, but it occasionally occurs in sperm cells. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 21. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 21 in each of the body's cells.
The most commonly found, and commonly known type of Trisomy eighteen which occurring in about ninety-five percent of all cases reported is the type known as full trisomy. During the formation of the full trisomy type of trisomy eighteen the extra chromosome occurs in every single cell in the baby’s body. This type of trisomy eighteen is not hereditary however, which means this type is not found as family trait, it is a random type. The next type of trisomy eighteen is known as partial or translocation, which happens to occurs in only about three percent of patients with trisomy eighteen. Partial trisomy eighteen occurs when people have two copies of chromosome eighteen instead of one, and a piece of extra genetic material from the chromosome eighteen. Partial Trisomy eighteen syndrome may be caused by hereditary factors. The final type of trisomy eighteen is known as the Mosaic Trisomy eighteen. Mosaic Trisomy is very rare type of trisomy ei, found in about two percent of all trisomy eighteen cases. Mosaic Trisomy eighteen is when an extra copy of the eighteenth chromosome is found in some, but not all of the cells in the person’s body. Mosaic trisomy eighteen is however not hereditary. No matter the type of trisomy eighteen a person is diagnosed whether it is full, partial, or mosaic, it is important that people understand that trisomy eighteen was not caused by anything done or not done by
In Ap biology, we were handed a Campbell Textbook before the class began in order to complete the pre-modules. I consider the textbook to be the most beneficial resource that we had during this course, due to the amount of detail, examples, and images that it contained explaining each concepts in a reliable way. The power points that were made to summarize the main points from the textbook were helpful, however they were really long and made me miss what was actually important and take additional notes on filler information. Due to the long powerpoints, I felt implied to take long and details notes, which people struggled in this class, either taking too much or too less. After two units passed, we were taught how our notes should be, which will later help us in college. This strategy allowed me to understand the important information and identify the filler information, resulting in
Klinefelter syndrome is a syndrome in which a person inherits an extra X-chromosome making their genetic makeup xxy instead of the normal
Cells that contain two sets on chromosomes are called diploid. This is represented as 2n, n=number of chromosomes in one set of chromosomes. Cells that contain one set of chromosomes is called haploid. This is represented as n.
3. Possible genotypes... Aunt 1 X --X, Aunt #2 X-- X, Aunt Dee X-- X, Michalla X-- X, Augusto X-- Y and Lorenzo X-- Y
Meiosis is a special type of cell division that occurs during formation of sperm and egg cells and gives them the correct number of chromosomes. Since a sperm and egg unite during fertilization, each must have only half the number of chromosomes other body cells have. Otherwise, the fertilized cell would have too many.
I am always fascinated at the many branches of Biology. The study of life is an idea that always manages to spark my curiosity, and it drives me into the enthusiastic research of the latest advancements into the field of science. Since my early years I found myself collecting plant leaves and looking at them through a microscope, and being baffled yet admiring of what I saw through the lens. Throughout my High School experience, I read articles ranging from creating 3D - printed limbs, organs, and tissue for people, to creating an anti-lymphoma vaccine that was made with tobacco leaves carrying RNA from cancerous B-cells. I follow newspapers for the breakthroughs in the cure for cancer, and I attentively pursued the Ebola outbreak in western
“The purpose of life is not to be happy. It is to be useful, to be honorable, to be compassionate, to have it make some difference that you have lived and lived well.” said Ralph Waldo Emerson. The life-saving knowledge people use to eliminate pathogens and to provide medical care comes from biologists. Understanding biology interests me greatly, not only because of expanding my knowledge of how organisms work, but also because of the potential to help the people suffering from diseases. My interest in the biological sciences began with my first biology class in middle school, and continued through high school.
While still in high school, before I even decided on which university I wanted to attend, I knew I wanted to study abroad and explore another country’s rich history and culture. Currently, I have never been outside of the United States, and while I love my country, I have always aspired to travel outside of it and pursue my passion for traveling. Being able to study my major of biology in another country with an exciting and different ecosystem would be an opportunity of a lifetime for me, and it would allow me to explore and appreciate the study of life in a contrasting and diverse ecosystem from what I am used to. Costa Rica would enable me to pursue my passion for biology in a unique environment where I can study tropical biology or conservation marine biology up close on a personal level.