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Biology chapter 9 meiosis
Biology chapter 9 meiosis
Essay of meiosis
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Recommended: Biology chapter 9 meiosis
Meiosis is a type of sexual reproduction that equally divides chromosomes between to new cells. The end results of the process are four haploid daughter cells produced from a diploid parent cell. Diploid is defined as a complete set of chromosomes in a cell. Meiosis requires two cycles of division, resulting in Meiosis I and Meiosis II. There are differences in both cycles, for example in Meiosis I results in two haploid (n) daughter cells. Haploid meaning each cell consists half the number of chromosomes from the original cell. Meiosis II, results in four haploid daughter cells. Both rounds consist of stages prophase, metaphase, anaphase, and telophase. In Meiosis I, the first stage is Prophase I in which DNA condenses to form visible chromosomes …show more content…
His first law is the Law of Segregation, which states that when an organism produces gametes, copies of genes are separated. Each gamete receives only one copy, that being one allele or the other. During Prophase I, chromosomes are separated and the alleles with the characteristics are divided into two gametes. Mendel’s second law is the Law of Independent Assortment, which states that alleles of different genes separate from one another during gamete formation. Mendel stated that different traits are inherited unaided, therefore there are no relations. Independent assortments occurs in Metaphase I, which aids in the increase of genetic diversity by making genetic …show more content…
Sickle cell disease describes not only one, but a set of inherited red blood disorders (NIH, 2015). The disorders affect hemoglobin, which is a protein in red blood cells that delivers oxygen to the cells throughout the human body. The disorder is inherited in an autosomal recessive pattern (UUHS, 2015). A child does not inherit the disease unless both parents give off a defective copy of the gene (UUHS, 2015). A person who inherits one good gene and one defective gene are simply carriers. The major phenotypic characteristics of an individual distinct to the disorder are the sickle shaped blood cells. Typically blood cells are round and flexible in order for them to travel easily through blood vessels. When people contain the disorder, their red blood cells are distorted by hemoglobin into a sickle, crescent shape (GHR,
In the 19th century Gregor Mendel accomplished pioneered the first laws of genetics after crossing peas. He conducted an experiment with pea plants. He would use a paintbrush to transfer the genetic coding from one pea plant to another, so he could know exactly who the parents were. With the end of this experiment Mendel came up with two laws; Mendel 's law of segregation, and Mendel 's law of independent assortment. Mendel crossed over purple pea flowers with white pea flowers, which gave him purple pea flowers for the first generation also called F1. Since the offspring were all purple flowers Mendel understood that the purple gene was the dominant gene. Mendel decided to cross the F1 generation with themselves. Which resulted in three purple pea flowers and one white pea flower. By using basic Punnett square, and identify the genotype as PP and the phenotype as pp. This gave Mendel the following ratio of 3:1, three purple pea flowers and one
The major topic of this experiment was to examine two different crosses between Drosophila fruit flies and to determine how many flies of each phenotype were produced. Phenotype refers to an individual’s appearance, where as genotype refers to an individual’s genes. The basic law of genetics that was examined in this lab was formulated by a man often times called the “father of genetics,” Gregor Mendel. He determined that individuals have two alternate forms of a gene, referred to as two alleles. An individual can me homozygous dominant (two dominant alleles, AA), homozygous recessive, (two recessive alleles, aa), or heterozygous (one dominant and one recessive allele, Aa). There were tow particular crosses that took place in this experiment. The first cross-performed was Ebony Bodies versus Vestigle Wings, where Long wings are dominant over short wings and normal bodies are dominant over black bodies. The other cross that was performed was White versus Wild where red eyes in fruit flies are dominant over white eyes.
Each cell contains the same genetic code as the parent cell, it is able to do this because it has copied it’s own chromosomes prior to cell death. division. The. Meiosis consists of two divisions whilst mitosis is followed. in one division; both these processes involve the stages of interphase, prophase, metaphase, anaphase, and telophase.
Sickle cell anemia is a genetic disorder that erythrocytes tolerate sickle shape red blood cells. These red blood cells are easy to damage, which leads to hemolytic anemia. Abnormal hemoglobin is fragile to low oxygen conditions within the body. It loses the blood solubility, and then forms thick strands called polymers. This gives the abnormal shape, called Sickle cell.
Sexual reproduction is that the union of male and feminine gametes to create a fertilised egg or zygote. The ensuing offspring inherit one-half their traits from every parent. Consequently, they 're not genetically similar to either parent or siblings, except within the case of identical twins. As theorised by Mendel, adults are diploid, meaning as 2N, having 2 alleles offered to code for one attribute. The gametes should be haploid, signified by N, containing just one allele in order that once 2 haploid gametes mix, they manufacture a traditional diploid individual. The method where haploid sex cells are created from diploid parents is known as meiosis, and it happens solely within the reproductive organs.
In the 19th century, Mendel’s relatively new science of inheritance and hereditary has increasingly developed into what we commonly understand today as genetics. Peter J. Bowler describes this field as becoming “a very active area of scientific research”.
Sickle cell anemia occurs when a person inherits two abnormal genes (one from each parent) that cause their red blood cells to change shape. Instead of being flexible and round, these cells are more rigid and curved in the shape of the farm tool known as a sickle - that's where the disease gets its name. The shape is similar to a crescent moon.
Sickle cell anemia is an inherited disease of red blood cells. Normally red blood cells contain a protein called hemoglobin A, which carries oxygen to all the organs in the body. With sickle cell anemia, however, the body makes a different kind of protein, called hemoglobin S.
A patient with sickle cell has inherited the condition from both parents, and it all starts in the hemoglobin. Hemoglobin is “an iron-containing protein in red blood cells that reversibly binds to oxygen” (Reece, Urry, Cain, Wasserman, Minorsky, & Jackson, 2011). Obviously, hemoglobin is an important substance for oxygen to be transported in red blood cells. However, a patient with sickle cell has irregular hemoglobin cause by inherited genes. This “oxygen delivery” system cannot function properly because a gene
Meiosis, also called reduction division, is a distinct type of cell division that is essential for sexual reproduction to occur. It is one in which two successive divisions of diploid cell occur thereby producing four genetically different haploid daughter cells, also called gametes, each with half the number of chromosomes and thus, half the total amount of genetic material as compared to the amount before meiosis began. Interphase precedes meiosis and thus, paves the way for meiosis to eventuate as the cell’s DNA replicates in the S phase yielding corresponding, identical chromosomes. Interphase sparks the marvelous process of meiosis that allows variation to transpire within the organisms it occurs, hence, giving rise to millions of organisms with unique aspects unlike any other on Earth. Because meiosis is a form of sexual reproduction itself, it is the means through which gametes are produced, each with a reduced number of chromosomes, so that when two gametes fuse during fertilization, not only do they form a diploid zygote with 46 chromosomes, but also have manifested differing features due to the rearrangement (crossing-over) of chromosomes.
Introduction: Genetics is the study of how genes and heredity combine to create traits in living organisms. Gregor Mendel disproved the theory that heredity comes only from parents. He discovered that there were dominant and recessive genes and his “Law of Dominance” has been used to selectively breed plants and animals for particular attributes. It has also been successfully adopted to identify the risk of passing down genetic diseases. Francis Galton took Mendel’s discoveries further by studying multifactoral inheritance and discovering ‘blending traits’, also known as continuous variation. With these traits, involvement of a wide range of genetic and environmental factors results in the creation of wide-ranging genotypes.
A chromosome is made up of two identical structures called chromatids. The process of nuclear division is called interphase; each DNA molecule in a nucleus makes an identical copy of itself. Each copy is contained in the chromatid and a characteristic narrow region called the centromere holds the two chromatids together. The centromere can be found anywhere along a chromosome but the position is the characteristic for a particular chromosome. Each Chromatid contains one DNA molecule. DNA is the molecule of inheritance and is made up of a series of genes. The fact that the two DNA molecules in the sister chromatids, and hence their genes, are identical is the key to precise nuclear division.
The differences between the two phases of meiosis are that in meiosis I, while the cell undergoes the phases, prophase I, metaphase I, anaphase I, and telophase I, it causes the cell to divide into two with each of the cells having a double stranded chromosome. But in meiosis II, it is just the division of the the cells from meiosis I. The ending result being that four haploid daughter
Meiosis is a specialized form of nuclear division in which there two successive nuclear divisions (meiosis I and II) without any chromosome replication between them. Each division can be divided into 4 phases similar to those of mitosis (pro-, meta-, ana- and telophase). Meiosis occurs during the formation of gametes in animals.
Once the sperm fuses with the ovum both chromosomes will pair up and begin the first stages of cell division.