Final Test
Explain in general terms the process of DNA replication.
The replication of the DNA starts when the double helix unwinds. Each of the two strands serves as the template using which the new DNA double helix strands are formed. The different bases on each of the two strands are then matched in order to form a new set of two strands. Each of the new strands partners with the parent strand to form a double helix (Roth 26).
Prophase – Chromatids are joined at the centromere. Spindle formation occurs. The separation of centrioles occurs in animal cells (Tobin and Jennie 63).
Metaphase – the chromosomes meet at the equatorial plane. The attachment of the chromatids to the spindle fibers occurs at the centromere (Tobin and Jennie 63).
Anaphase – The separation of the chromatics in every chromosome occurs (Tobin and Jennie 63).
Telophase – the daughter chromosomes are enveloped in a nucleus. The nucleoli are formed after which the spindle fibers wither (Tobin and Jennie 63).
Compare and contrast mitosis and meiosis.
Mitosis differs from meiosis in a number of ways as summarized below. The similarities are also summarized in the table.
Source: (Santos and Danac 209).
Explain biological magnification.
This is a concept that describes the manner in which poisonous substances increase their toxicity as the poisonous substance are consumed by organisms that are higher in the food chain. For instance, if a small fish consumes algae or planktons that contain mercury, the toxicity of the mercury increases as the fish are consumer by their predators until man catches the big fish and eats it (Starr, Christine and Lisa 476).
The ecological perspective considers the environment as all the natural factors that have an influence on the living organisms. The natural resources in northern Africa have been depleted due to mismanagement (Harris and Roach 12). The famine results from the lack of natural resources to sustainably support farming.
Pick an ecological issue to discuss. Include in your discussion possible solutions to the problem.
One of the significant ecological issues is resource depletion. The natural resources can affect the living organisms by way of providing sustenance. The misuse of the natural resources results in depletion. This problem can be solved by resource management and conservation (Harris and Roach 12). The determination of the extent of the resource can help in the determination of the manner in which it will be used.
Describe the factors that influence the biotic potential of a particular species.
The biotic potential of organisms is affected by the pressure that is exerted on a certain species by other organisms. These factors include predation, disease, competition, and inferior genetic traits. For instance, competition results in the reduction of resources thereby limiting growth. The occurrence of diseases can lead to the extinction of a species through death (Raven, Linda and David 91).
If a women's father is color blind, what is the probability that her son will be color blind? What is the probability that her son's daughter will be colorblind? Color blindness is X-linked inheritance.
If the father is color blind, then the woman has a recessive gene for color blindness. There is a 100% chance that her son will be color blind, especially the son who takes the X chromosome with the recessive gene from the woman. However, the son’s daughter has zero chance of being color blind if the son marries a woman who has no recessive allele for color blindness.
In humans, freckles are dominant to no freckles. A man with freckles is married to a woman with freckles, but the children have no freckles. What is the deal? (Assume no indiscretions have occurred).
The man and the woman were heterozygous for freckles. The possibility that their first filial generation would have freckles was 75% with a mixture of both homozygous and heterozygous genotypes. The remaining 25% had the recessive alleles and it did not develop, hence the children with no freckles.
Determine the protein (amino acid sequence) from the following mRNA.
5’ AUG-GCU-UUC-CUA-AUA-UAA-CAU-AUC 3’
The following is the amino acid sequence
Methionine-Alanine-Phenylalanine-Leucine-Isoleucine
Explain the difference between sex-linked and sex-influenced inheritance.
Sex-linked inheritance is different from sex-influenced inheritance in that sex-linked inheritance occurs more in males than in females. The reason behind this occurrence is that the female chromosomes have two X genes. This is one more X gene than in the male chromosome. The extra X gene counteracts the effect of the recessive trait, hence the higher expression in males than in females (Hay and Virginia 6). Conversely, sex-influenced inheritance is influenced by sex in that while a male with a recessive allele will still express the trait, a female would require the two recessive alleles to express the trait (Hay and Virginia 6).
The mode of inheritance is the sex-influenced inheritance
In the first pedigree, the male and female parents’ genotypes are heterozygous for the trait. In the second pedigree, the male parent does not have the trait, hence has a homozygous recessive allele for a genotype but the female parent’s genotype is heterozygous for the trait. In the third pedigree, the male parent’s genotype has a homozygous recessive allele. In the fourth pedigree, both parents’ genotype is heterozygous for the trait while the female parent’s genotype is homozygous for the trait by with the recessive allele.
Bonus: there is a 3/8 chance that there will be four boys and four girls
Works Cited
Harris, Jonathan and Roach, Brian. Environmental and Natural Resource Economics: A Contemporary Approach. London. Routledge. 2016. Print.
Hay, Meredith, and Virginia, Miller. Principles of Sex-Based Differences in Physiology. Amsterdam [u.a.: Elsevier, 2004. Print.
Raven, Peter, Linda, Berg, and David, Hassenzahl. Environment. Hoboken, NJ: Wiley, 2012. Print.
Roth, Stephen M. Genetics Primer for Exercise Science and Health. Leeds: Human Kinetics, 2007. Print.
Santos, Gill and Danac, Alfonso. Biology for High School. Manila. Rex Book Store. 1999. Print.
Starr, Cecie, Christine A. Evers, and Lisa Starr. Biology: Concepts and Applications Without Physiology. Belmont, CA: Thomson / Brooks/Cole, 2008. Print.
Tobin, Allan and Jennie Dusheck. Asking About Life. Belmont, Calif: Brooks/Cole, 2005. Print.
