Please answer the following questions in a 200-word response minimum. Try your best to reference the text I will message you privately for how to access the text book.
1. Do Mendelian rules of inheritance apply to all traits? Why or why not? Discuss an instance where Mendel’s rules may not be applicable and what would have happened had Mendel chosen a trait that does not follow the rules of Mendelian inheritance.
2. Why is there a need for mitosis and meiosis? Are there characteristics that make them redundant? Explain. If you created an organism, would you use mitosis or meiosis in reproduction? Why? Provide two examples in nature of organisms that only use one process.
3. If you and your sister are products of your parent’s genes, how do you account for genetic variation between you? Is there genetic variation between twins? Explain.
4. Which is more important in sex determination, the sex chromosomes or genes in an individual? Why? Using an example of a sex-linked trait, discuss how sex linkage affects the way this trait is inherited in males versus females.
5. Karyotyping employs identifying chromosomes by their physical appearance. What conclusions can one draw from an abnormal karyotype and the different types of genetically inherited diseases or abnormalities?
6. Prior to the assignment of genes to particular chromosomes, geneticists used a variety of hybrid crosses and mathematical analyses to show that two genes were linked and thus were inherited together or were distant from each other and segregated independently. Discuss the uses of mapping, mathematical analysis, and pedigree analysis in understanding human inheritance.
Please participate (respond) to the classmate’s answers with POSITIVE notable and educational input. (200 word minimum Reponses)
1. Carlianne: Both mitosis and meiosis are needed for reproduction because they both account for two different and crucial types of reproduction: asexual reproduction and sexual reproduction. Mitosis is extremely important for the development and growth of organisms, cell replacement in organism, and asexual reproduction. During this process the parent cell DNA is duplicated and divided so that the two daughter cells have identical genes and chromosome compliments of the parent cell. Meiosis is also crucial to reproduction in many organisms. Meiosis results in the 4 daughter cells with half the genetic make up of the parents cells and leads to gametes and spores. Meiosis is also very important for providing genetic variation between the offspring of materal-paternal chromosome combinations. Based on this information it is clear that both mitosis and meiosis are necessary because mitosis is crucial for asexual reproduction (single cell organisms, plants, and cell repair) and meiosis is crucial for sexual reproduction (humans and animals).
If I could create a new organism, I think that I would keep the reproductive processes of mitosis and meiosis identical to how things are currently in humans and animals. I would use both processes because based on the readings and my further research on mitosis and meiosis both are important to sexual and asexual production, an organism’s growth, cell repair and replacement, and providing significant genetic variation. I would include both processes because meiosis is essential for genetic diversity between parent cells and their offspring’s. If mitosis was the only process included the daughter cells created would be identical to the mother cell results in identical offspring. Also, meiosis is necessary for sexual reproduction to occur because the DNA of the materal-paternal cells must be cut in half (23 chromosomes) in order to produce of offspring with 46 chromosome.
Bacteria is one organism that only uses one process to reproduce. Because they are prokaryotic organisms and they do not have a membrane surrounding their DNA, the DNA will copy and split in half, dividing the cell in two through a process called binary fission. There are also some species of worms (ex: blackworms) that reproduce using only one process. These worms can reproduce sexually but often reproduce asexually using one process called fragmentation. The worm will break in half and each fragment will become a new worm.
2. Scott: Meiosis and mitosis are both needed because there are different types of reproduction; sexual and asexual reproduction. Sexual reproduction is done by meiosis when a sperm cell and an egg cell combine to make a zygote, the first cell in the new organism.
Asexual reproduction happens in everything that does not use sexual reproduction to reproduce. Asexual reproduction is done by mitosis which is when “one replication and one division of the chromosome material occur resulting in the chromosome numbers in the two cells produced being the same as in the parent cell (Meister, 2016).” Mitosis is the reproduction of cells in humans like skin cells, ones that do not need sexual reproduction to make copies of them.
From what I understand about meiosis and mitosis they are both needed in their own reproduction type. Sexual reproduction for example humans and animals would not be possible without meiosis and asexual reproduction for example plants and skin cells would not be possible without mitosis.
If I created an organism I think I would use both as the reproductive methods like animals do. I think that is a great combination of methods because you have sexual reproduction to create the organism and asexual reproduction to help it grow and recover from injuries like human skin grows back when it is damaged by way of mitosis. If humans didn’t have this ability there would have to be sexual reproduction to make the new skin instead of the cells just splitting and regrowing.
An example of an organism that only uses mitosis is bacteria; they only reproduce through binary fission. From what I can find in my studying there are no organisms that only use meiosis to reproduce. There are some cells that only use meiosis but those cells help make up an organism that needs both meiosis and mitosis to reproduce.
Meister, D. (2016). Biological Significance of Mitosis & Meiosis in Sexual Reproduction.
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