Examining Mendel’s “First Law”: Observing Anthocyanin in Brassica rapa
Abstract
The foundation of genetics lies with the principles that Gregor Mendel outlined after his experiments with pea plants where he discovered the relationship between physical characteristics, or phenotype, and genetic traits, or genotype. This experiment aimed to reproduce Mendel’s results with the Brassica rapa plant, noted for it’s fast generation time, and anthocyanin, a purple pigment that can be visually tracked through subsequent generations. It is important for experiments resulting in scientific discovery to be replicable and peer reviewed. Since Mendelian genetics are the foundation of scientific education, including answering questions about
…show more content…
Other forms of the genotype, (ygr/ YGR) and (YGR/YGR) will result in green leaves. A third gene in Brassica rapa is the rosette mutant, homozygous recessive. The genotype needed for the short, rosette plant form is (ros/ros). The other two genotypes (ros/ROS) and wild type (ROS/ROS) will result in the normal form of the plant. The phenotypes and genotypes are related in that the phenotypes provide a visible indication of the genotype. This is true in an individual with a homozygous recessive gene. However, in the case of dominant genes, since only one copy is needed for the phenotype to be present, then the second copy is not indicated. The second copy can be identified process where two individuals (P1 and P2) with the same dominant phenotype, called the parental generation, are bred. This produces an F1 or first generation of offspring. The F1 generation can also be bred and produce an F2 generation. Each individual in the F1 and F2 generations receives one copy from each parent of the 3-letter genotype code, called an allele.
Gregor Mendel theorized that certain combinations of alleles in a genotype would result in a specific ratio of phenotypes expressed in each generation. For example, in the case of the dominant heterozygous anthocyanin genotype, the P1 with (ANL/anl) crossed with the P2 (ANL/anl) would result in a 1:2:1 ratio for genotypes (ANL/ANL), (ANL/anl) and (anl/anl). However,
The purpose of Mendelian Genetics: Fast Plant lab is to determine if Mendel’s law of segregation applies to the reproduction of the Brassica Rapa. The law of segregation suggest that allele pairs separate during the production of gametes. Which then the offspring gets one factor from each of the parents. To show this, Mendel suggests that the F2 generation plants will have a three to one ratio between anthocyanin gene (purple) and the absence of the anthocyanin gene (green). The purple stem being the dominant allele and the green stem being the recessive allele. In the lab, we harvest F1 hybrid seeds of the Brassica Rapa and pollinated them so we can have a monohybrid cross between the plants. This will show us the F2 generation of Brassica
The “Brassica rapa” is a fast plant known as the field mustard. This plant is well known for its rapid growing rate, which makes it an easy breeding cycle and easy to pollinate. In giving so this makes “Brassica rapa” a great participant for testing Gregor Mendel’s theories of inheritance. The “Brassica rapa” acts like a test subject in testing cross-pollination giving the understanding to the dominant allele of colored stems. There are different colors that are visible on the stem that are above the soil; the colors vary from green to purple. P1 seed was ordered, germinated and cross-pollinated until germination of the next off spring of plants were also done. It was
You are also provided with a heterozygous female, and a homozygous recessive male for a genetic cross. In this particular female, all the dominant alleles are on one chromosome, and the recessive counterparts are on the other homologous chromosome. Due to a chromosomal condition, in the female no recombination occurs between the M and N loci. Normal recombination occurs between the L and M loci. Diagram this cross, and show the genotypes and frequencies of all offspring expected from this cross.
As “the father of modern genetics”, Mendel made a huge impact on science by discovering the basic laws of heredity, with dominant and recessive traits. Through these discoveries he inspired many scientists to jump onto genetics and try to replicate his experiment to confirm his results.
3. Carlson, Elof Axel. Mendel's Legacy: The Origin of Classical Genetics. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory, 2004. Print
The topic of genetics have fascinated scientists ever since the 1800’s when Gregor Mendel became the “father of genetics. Gregor Johann Mendel's study with peas revolutionized the field of biology. Using the peas, he was able create the foundation of genetics. Mendel's study was performed by crossing peas of differing variation to created a sequence of offspring. Initially, monohybrid characteristics, singe traits that only affected each other, were observed. Surprisingly, he found a ratio of 3:1 dominant to recessive genes in the first generation of peas. He also figured out that phenotypes that weren’t seen in the first generation are found in the second generation due to the dominant representation of dominant alleles. Then, dihybrid characteristics,
Gregory Bateson was born in Grantchester, England to an aristocratic family in 1904 (Stagoll 2006). His father, William Bateson, was a prominent geneticist who founded the Cambridge School of Genetics and coined the term “genetics (Stagoll 2006).” William Bateson was a strong advocate of the work of geneticist Gregor Mendel and named Gregory in his honor (Stagoll 2006). Following in his father’s footsteps, Gregory Bateson received his bachelor’s degree in natural sciences at St. Johns at Cambridge where his grandfather, William Henry Bateson, held the position of master (Levy and Rappaport 1982). After publishing his first paper about
Gregor Mendel is known as the father of modern genetics because of the research and experiments he did by breeding pea plants and examining their physical appearances. He studied the plants seed color and shape, pod color and shape, and flower color and position. Mendel collected the seeds from pods produced after fertilizing two parent pea plants and then grew those seeds into new plants and observed how the offspring resembled or differed from the parents. After all of his experimentation, Mendel was able to conclude 3 principles. The principle of segregation, which meant that each organism has two alleles for each gene, one from each parent that separate
Mendel found out that organisms can have the same phenotypes, but have different underlying genotypes.
“My scientific studies have afforded me great gratification: and I am convinced that it will not be long before the whole world acknowledges the results of my work.” -Gregor Mendel. Gregor Mendel, a.k.a “the father of genetics” was an Austrian monk and he is credited for discovering hereditary units. Mendel discovered hereditary units by breeding thousands of plants. Mendel specifically chose pea plants because they reproduce quickly and he could control how they mated. The pea plants showed Mendel that genes were hereditary. Mendel’s knowledge of genetics and heredity is relevant in today’s society for many reasons.
Gregor Mendel worked to bring about Mendelian inheritance. Genetics can be defined as: the study of heredity and variation of inherited characteristics. Mendel worked in the lab on pea plants. Therefore, in Figure 1A it shows how from working with the pea plants he concluded that genes come in pairs and are inherited as distinct units with one inherited from each parent. He also tracked the segregation of parental genes and their appearance in the offspring as dominant and recessive. This was a major breakthrough in genetics.
This lab report serves the purpose of explaining the Mendelian theory on genetics. An experiment done on the common fruit fly shows how the dominant and recessive traits appear in the generation tested. The data collected and found by using a chi-square and Punnett square that allowed a hypothesis to be made and the decision to be accepted or rejected. Drosophila Melanogaster, the common fruit fly is an essential organism to use for genetic research because of its simple living requirements and choice of diet. The fly can also be easily sedated and obtains many hereditary features that can be seen with the naked eye. The fly has a few chromosomes. Another plus in using the Drosophila is its short life cycle. The average life cycle is about 12 days. The eggs are small and after a day are hatched into the larva. While the Drosophila is in the larval stage, it is constantly eating. As it grows, the larva will shed its skin. Then in the last few stages, the chromosomes will be visible. While in the pupal stage, the larva will crawl to the side of the container to begin forming the pupal case, which is darker and harder. After a few weeks, the adult fly crawls out of the casing and begins mating to restart the cycle (Vijayalakshmi 5). During this fly lab, the investigation was based on genetics and gave ratios when the crosses were performed. The first objective was to find the dominant allele. The dominant allele is the more powerful gene in the crossing. There is also a
The scientist at the epitome of all scientific discoveries is Gregor Mendel. His scientific breakthroughs changed the world of genetics. Mendel shed new light on heredity. When people questioned why they have certain traits, he sought out an answer and proved it scientifically. Scientist still use his methods in genetics today. Gregor Mendel’s early life and schooling made an impact on the accomplishments and discoveries that created the legacy of the “Father of Genetics.”
In this lab we considered Gregor Mendel theory of genetics. Mendel was a botanist and statistician. Mendel worked with garden peas to figure out their genetic pattern. The peas were also true-breed.1 The three principles that Mendel had for inheritance pattern are the principle of segregation, principle of dominance, and principle of independent assortment.2 The first principle of segregation means that the individual gets part of the trait from each parent that makes their traits.2 The second principle of dominance is that a trait may be present during the first generation, but doesn’t not mean it could be present in future generations and that the dominant allele is showed. The third principle of independent assortment is that it depends on the different units that are passed on that can decide your traits based on other traits that are given.2 This now goes into showing that variation of a gene is called an allele. This is now shown in a phenotype and genotype. A phenotype is showing he physical trait that we can see. A genotype is the showing of the genetic form that made that trait.3 Another term we used in this lab was homozygous which means you have two of the same alleles. The next term that was used is heterozygous which means that two different alleles were used. The term that was important that we used was a Punnett square. A Punnett square is way to be able to calculate the different potential outcomes of the genotypes graphically.3
Genetics is a field of biology, which concentrates specifically on the study of genes, heredity, and genetic variation among living organisms. The use of genetic knowledge can be traced to early civilizations when people examined and altered genetic information to advance the efficiency of domesticated species of plants and animals. Some of the plants, such as corn, wheat and rice, were genetically modified not only to increase the production of crops, but to also be resilient against diseases and pest, while at the same time still producing a nutritious and healthy harvest. About one hundred and fifty years ago, Gregor Mendel observed heredity through his experimental work on the production of pea stocks. Mendel came up with groundbreaking conclusions over eight years and with the use of twenty eight thousand pea plants as he discovered dominant and recessive genes to be the major building blocks of heredity while incorporating mathematics to identify patterns in his experiment (Wilson, Avery, Ford, Hancock, Read, Stephens, and Young, 2007). Mendel carried out monohybrid and dihybrid crosses and was able to obtain offspring in certain ratios that allowed the establishment of the laws of inheritance.