Chromosomes

Cri du chat Syndrome Cri du chat syndrome is an uncommon genetic condition that is caused by missing genetic material on chromosome 5. Specifically a part on the small arm (p) of chromosome 5 is absent. The disorder occurs in 1 in 20,000 to 50,000 live births according to the US National Library of Medicine. What causes this to happen is currently unknown. Cri du chat syndrome was first described in 1963 by French geneticist Jérôme Lejeune. He noticed that several of his patients…

same number of chromosomes. Mitosis has interphase, prophase, metaphase, anaphase, and telophase. In interphase, the chromosomes have already been replicated. In interphase, chromosomes duplicate. During prophase, spindle fibers attach at each centromere. In metaphase, the chromosomes line…

(3.) The percentage of Allison’s egg cells that she produces during her lifetime that will carry the recessive allele and the X chromosome is seventy five percent. For the fact, twenty five percent of the cell will carry homozygous recessive allele and X chromosome, the other fifty percentage will carry heterozygous recessive allele and X chromosome. (4.) A. Twenty Five Percent B. No. C. (X)R (X)r (X)R (X)R(X)R - Female homozygous dominant (X)R(X)r - Female heterozygous…

Insoo Cho Dr. Danzi Engoron BI356 Genetics Currently, there are more than 600 genetic disorders known, all caused by defective genes. Genetic disorders result from the accumulation of the harmful substance in the body or from an inability of the body to produce or utilize essential substances that influence development and function. Most of the time genetic disorders are passed down through family, however, sometimes they can also be due to gene mutation caused by a combination of both…

that are received through an individual having an abnormality in DNA”(Genetic Science Learning Center, 2014). These irregularities range from single-base mutations on just one chromosome all the way up to receiving or removing an entire chromosome. In the case of neurofibromatosis, it is caused by an anomaly in a single chromosome. Neurofibromatosis, also known as NF, has two distinct types called NF1 and NF2. “NF1 occurs in approximately 1 in 4,000 births, whereas NF2 occurs about 1 in 40,000…

pre-existing living cells, through cell division. In cell division, this involves the supplying of identical genetic material from the parent cell, DNA and protein, to two daughter cells. It results in the daughter cells having the same number of chromosomes as the parent cell. We need cell division as it is used in reproduction of new species, growth and repair of damaged cells and tissues, and to reduce the cell size. Larger cells are insufficient, as it needs more nutrients (such as sugar and…

fertilize the egg as opposed to monospermy, which is the normal fusion of one sperm nuclei with the egg nuclei creating a diploid nucleus and therefore a viable zygote. Polyspermy will result in an egg that contains more than two copies of each chromosome (for example, forming a triploid nucleus) and typically results in a zygote that is unviable. There are two mechanisms that exist to prevent polyspermy. The first is fast block to polyspermy. As the sperm enters, the membrane potential…

In mitosis, a cell produces two clones of itself, each with the same number of chromosomes. In meiosis, a cell will produce four cells called gametes through the process of spermatogenesis and oogenesis. Gametes are most commonly known as sperm cells in males and egg cell in females. Unlike mitosis, the gametes that meiosis produces are not clones of the original cell as each gamete has exactly had as many chromosomes of the original cell and are all different from one another (siblings).…

While in the Meiosis there takes cell div ision two times but chromosomes divides only single time. 2) Mitosis usually occurs in the somatic cells. While Meiosis takes place in the germ cells. 3) Mitosis generally takes place in both sexually and asexually reproducing organisms. While we should know that Meiosis only…

divide and reproduce, but they also have many differences. Meiosis is the type of nuclear division that occurs in sexually reproducing organisms. In meiosis, the diploid number of chromosomes is reduced to the haploid number. Gametes have the haploid number, while zygotes have the diploid number. The homologous chromosomes that appear in the zygote look alike and have the same length and centromere position, but the genes they hold may be for opposing traits. After duplication, the homologues…