What did Thomas Hunt Morgan discover?

Answers

Answer 1

Answer: Thomas Hunt Morgan hoped to discover large-scale mutations that would represent the emergence of new species.

Answer 2

Answer:
1910

Thomas Hunt Morgan (1866-1945) establishes the chromosomal theory of heredity

Thomas Hunt Morgan, an embryologist who had turned to research in heredity, in 1907 began to extensively breed the common fruit fly, Drosophila melanogaster. He hoped to discover large-scale mutations that would represent the emergence of new species. As it turned out, Morgan confirmed Mendelian laws of inheritance and the hypothesis that genes are located on chromosomes. He thereby inaugurated classical experimental

After breeding millions of Drosophila in his laboratory at Columbia University, in 1910 Morgan noticed one fruit fly with a distinctive characteristic: white eyes instead of red. He isolated this specimen and mated it to an ordinary red-eyed fly. Although the first generation of 1,237 offspring was all red-eyed but for three, white-eyed flies appeared in larger numbers in the second generation. Surprisingly, all white-eyed flies were male.

These results were suggestive for hypotheses of which Morgan himself was skeptical. He was at the time critical of the Mendelian theory of inheritance, mistrusted aspects of chromosomal theory, and did not believe that Darwin's concept of natural selection could account for the emergence of new species. But Morgan's discoveries with white- and red-eyed flies led him to reconsider each of these hypotheses.

In particular, Morgan began to entertain the possibility that association of eye color and sex in fruit flies had a physical and mechanistic basis in the chromosomes. The shape of one ofDrosophila's four chromosome pairs was thought to be distinctive for sex determination. Males invariably possess the XY chromosome pair (Morgan used a more cumbersome notation) while flies with the XX chromosome are female. If the factor for eye color was located exclusively on the X chromosome, Morgan realized, Mendelian rules for inheritance of dominant and recessive traits could apply.

In brief, Morgan had discovered that eye color in Drosophilaexpressed a sex-linked trait. All first-generation offspring of a mutant white-eyed male and a normal red-eyed female would have red eyes because every chromosome pair would contain at least one copy of the X chromosome with the dominant trait. But half the females from this union would now possess a copy of the white-eyed male's recessive X chromosome. This chromosome would be transmitted, on average, to one-half of second-generation offspring—one-half of which would be male. Thus, second-generation offspring would include one-quarter with white eyes—and all of these would be male.

Intensive work led Morgan to discover more mutant traits—some two dozen between 1911 and 1914. With evidence drawn from cytology he was able to refine Mendelian laws and combine them with the theory—first suggested by Theodor Boveri and Walter Sutton—that the chromosomes carry hereditary information. In 1915, Morgan and his colleagues published The Mechanism

• Discrete pairs of factors located on chromosomes like beads on a string bear hereditary information. These factors—Morgan would soon call them genes—segregate in germ cells and combine during reproduction, essentially as predicted by Mendelian laws. However:

• Certain characteristics are sex-linked—that is, occur together because they arise on the same chromosome that determines gender. More generally:

• Other characteristics are also sometimes associated because, as paired chromosomes separate during germ cell development, genes proximate to one another tend to remain together. But sometimes, as a mechanistic consequence of reproduction, this linkage between genes is broken, allowing for new combinations of traits.

Morgan's experimental and theoretical work inaugurated research in genetics and promoted a revolution in biology. Evidence he adduced from embryology and cell theory pointed the way toward a synthesis of genetics with evolutionary theory. Morgan himself explored aspects of these developments in later work, includingEvolution and Genetics published in 1925, and The Theory of the Gene in 1926. He received the Nobel Prize in Physiology or Medicine in 1933.

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Assume that a mutation occurs in the gene responsible for the production of hexosaminidase a, such that only about 50% of the enzyme activity is found in the heterozygote compared with a homozygous normal individual. if heterozygotes are phenotypically normal, we would say that the mutant allele is recessive to its normal allele.

Answers

This statement is true.

In the case of autosomal dominant disease, the person is either homozygous (which is very rare) or heterozygous. On the molecular level, either the mutation produced a new deleterious protein for the organism, or the mutation affected an existing protein in the physiological state and that a 50% activity is not enough to compensate for the needs. of the body.

In case of autosomal recessive disease, the sick person is always homozygous. If the two loci each have a different mutant allele, it is called a "composite heterozygote". People with autosomal recessive inheritance disorder have "mandatory heterozygote" parents.

During a(n) _______________ change, a system absorbs energy from its surroundings.

Answers

Answer: Endothermic

Explanation:

An endothermic reaction occurs when energy is absorbed as heat, while a reaction is exothermic when heat is released. Thereby, these type of reactions require external energy to proceed and heat is the reactant.

So, an endothermic reaction absorbs heat from the surrounding environment and stores that energy in the bonds of a new molecule formed, and this results in a decrease in temperature.

Enthalpy usually increases in endothermic reactions. However, a spontaneous endothermic reaction can occur if changes in entropy and enthalpy yield a negative Gibbs free energy.

endothermic (I have to fill in 20 characters so please ignore the parentheses)

A land-dwelling organism, A, and an aquatic single-celled organism, B, are represented below.

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Using the image that represents the land-dwelling organism and an aquatic single celled organism. The statement that best explains how A and B are able to survive in their environments is…

Answer: A) The organelles in B perform similar functions to the organ systems in A.

Please see image attached to better understand how we arrived to the conclusion.

I hope it helps, Regards.

Why is dna extraction and isolation an important laboratory technique?

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Answer: dude just search it up lol

Explanation:

If the chemical enzyme pepsin was mixed with some proteins in a test tube in a laboratory, which of these outcomes would you predict?

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Answer:

Pepsin breaks the proteins into simple amino acids.

Explanation:

Digestion is the process of break down of the larger food particles into the simpler substances. The digestion process requires enzymes and digestive juices.

Proteins are made of the amino acids. The enzyme pepsin helps in the breakdown of proteins into the simple peptides. The proteins present in the test tube is hydrolyzed by the enzyme pepsin and breaks down the proteins into simpler amino acids.

Thus, the answer is pepsin breaks the proteins into simple amino acids.

pepsin is one of three principal protein-degrading enzymes in the digestive system, the other two being chymotrypsin and trypsin. During the process of digestion, these enzymes collaborate to break down dietary proteins to their components, i.e., peptides and amino acids.

How does taxonomy help us understand relationships among organisms on earth? What kinds of evidence do scientists use in taxonomy?

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Taxonomy helps us understand relationships among organisms on earth because you can produce a genetic tree diagram which starts from present day animals and goes back to the first early life forms. Scientists will use living organisms and extinct organisms either from fossils, from drawings or from photographs

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