1. Explain why evolution often selects traits that promote genetic diversity.
Evolution often selects traits that promote genetic diversity because genetic diversity boosts the chances that at least some members of the population will have a combination of traits that will allow them to survive and reproduce in a changing environment. Organisms that rely on asexual reproduction have virtually identical offspring, and they are successful in a stable environment; however, conditions rarely remain constant on Earth. Therefore, evolution favors traits that promote genetic diversity because the conditions on Earth are always changing, and genetic variability provides organisms a better chance of survival than organisms that do not have genetic variability.
2. Describe a situation in which asexual
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Is it possible for a boy-girl pair of twins to be genetically identical? Why or why not?
No, it is not possible for a boy-girl pair of twins to be genetically identical. This is impossible because females have two X chromosomes, and males have one X chromosome and one Y chromosome. Therefore, a boy-girl pair of twins would be genetically different since their sex chromosomes differ.
7. List some examples of chromosomal abnormalities and explain how each relates to an error in meiosis.
Some examples of chromosomal abnormalities are extra autosomes, extra or missing sex chromosomes, deletions, duplications, inversions, and translocations. Extra autosomes and extra or missing sex chromosomes relate to errors in meiosis because they are the result of chromosomes failing to properly separate in meiosis.
Deletions, duplications, inversions, and translocations relate to an error in meiosis because they are a consequence of homologous chromosomes failing to align correctly in meiosis or result from errors when crossing over occurs. 8. Could nondisjunction occur during mitosis? Compare and contrast the likely consequence of nondisjunction in mitosis vs.
• Two haploid daughter cells are formed o Sister chromatids separate in meiosis ll • Second division that separates sister chromatids • Chromatids may not be identical due to crossing over in prophase I • Chiasmata formation between non-sister chromatids results in the exchange of alleles o Crossing over is the exchange of DNA material between non-sister homologous chromatids • When chiasmata is formed between the bivalents in prophase I, DNA is exchanged between the non-sister homologous chromatids • Crossing over results in production of new allele combination on the chromosomes • Recombinant chromosomes consist of genetic material from both homologues o Crossing over produces new combinations of alleles on the chromosomes of the haploid cells • Genes may be linked or unlinked and are inherited accordingly o Gene loci are said to be linked if on the same chromosome / • Linkage group is a group of genes whose loci are on the same chromosomes and don't independently assort • Linked genes tend to be inherited together • Don't follow the normal dihybrid cross • Phenotypic ratio is more closely assigned to monohybrid cross as two genes are inherited in a single unit • Linked genes may become separated through
Some examples of this hinted in the article are selection, genes, and environmental factors. Selection is the inheritance of survival, genes create variation, and geographic barriers is explained in the
There are 2 ways to look into evolution, it’s either by Red queen model or Court Jester model. The “Red Queen” model come from Darwin, it’s an evolutionary hypothesis which proposes that organisms must adapt, evolve, and survive to gain reproductive advantage. In a Red Queen world, the species diversity is depends primarily on body size, width of physiological tolerance, or adaptability. The Court Jester model is different from Red Queen model because evolution, speciation, and extinction rarely happen except in response to undeterminable changes in the environment. In a Court Jester model, species diversity depends on unfaithfulness of climate, landscape, and food supply.
When people think of twins, they usually imagine two people looking exactly alike, dressing exactly alike, and completing each other’s sentences. Most imagine having a twin would be wonderful, after all, you could switch classes in school and read each other's mind, what’s not to like? However, most people are completely unaware and insensitive to the struggles of being a twin. Society generally views twins as two people wrapped in one rather than two independent individuals. As a twin myself, I have spent much of my life trying to establish my own identity.
Does In Vitro Fertilization increase the number of chimeras? Done by: Rofhiwa Ralinala Table of contents: 1. Introduction: Page 3 2. Background: Page 3 3. Methodology:
Sexual selection is another mechanism of evolution that involves the passing down of more attractive and appealing traits. The final mechanism is natural selection and this mechanism is the most important for evolution. Natural selection is the selection of individuals that possess more favorable traits in an environment. These favorable traits will be passed down to future
“Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time.” (Carol, n.d). The random fluctuations of variants alleles are mostly express on small populations. For instance, when a population goes to bottleneck which cause the reduction of population causing the extinction of infrequent alleles. It is important to note that genetic drift drives evolution by producing new genetically different population from its starting population.
Despite the discovery of millions of new species and many scientific breakthroughs, the question of how the diversity of life came about on the planet still remains. There are many scientists whom have committed their time into discovering and proposing new answers to this question. The majority of the main theories involve the idea that evolution serves as an understanding of how two species can evolve from one (WGBH Educational, 2001). Slide
Darwin’s theory of evolution by natural selection explain that organism’s trait favored by their environment are more likely to survive and successfully pass down their gene. There are varieties in a population of organisms. Some heritable traits are passed down to the next generation. Individuals with the traits that are favored by their environment are better adapted to survive and reproduce. More organisms are produced than the environment can hold.
Unlike natural selection, genetic drift is random and rarely produces adaptations to the environment. It is important to note however that the neutral theory does not suggest that: organisms are not adapted to their environments; all morphological variation is neutral; all genetic variation is neutral and that natural selection is unimportant in shaping genomes. It in facts believes that natural selection helps to rapidly purge the genome of deleterious
Charles Robert Darwin, born February 12, 1809 in Shrewsbury, England, is best known for his work as a naturalist, founding a theory of evolution to explain biological change and for his book The Origin of Species. Darwin greatly influenced the world we live in today. No matter a person’s religious or scientific stance, the process of evolution cannot be denied. Archaeological investigations have proven that species evolve over time, but the unanswered questions are “How?” and “Why?” The answer lies in Darwin’s theory of evolution.
In the environment, individuals have the capability to produce more offspring than the environment can successfully sustain. Consequently, numerous organisms will not survive long enough to reproduce offspring. Therefore, species will adapt in various ways over time to enhance their ability to survive. The theory of evolution by natural selection was created by Charles Darwin and Alfred Russell Wallace (Schussler 2014). Natural selection portrays a species ability to adapt over time from generation to generation to survive and be the most advantageous reproducer and predator (Freeman 2014).
Unlike twins Have you ever seen unlike twins? Me neither, until my sisters were born. When someone mentions the word “twin” our brain immediately visualize two persons or things that are equal, or at least that have many similarities. In this particular case, my sisters are the contrary of everything that our mind is imagining about the genetic concept of being a twin. Afterwards, one day one of them was lost in a park for about 45 minutes.
Student ID = mc170404399 ASSIGNMENT NO : 2 Q 1 . Differentiate between somatic and germline mutations ? Give at least two examples of each. In biology, a mutation is the lasting modification of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements.
Mutations are generally deleterious and are selected against. But the genome of a species can undergo another type of change, gene duplication, which actually favors mutational events. If a single gene that is important undergoes a duplication, mutation in the duplicated copy would not necessarily reduce the fitness of the individual because it still would have a functioning copy of the original gene. With this adaptive constraint removed, further changes can occur that generate a new gene that has a similar function in the organism, but may function at a specific time in development, or in a unique location in the individual. This type of evolution generates multigene families.