Flood Bio DB

4

Question 1

Sexual reproduction has number of advantages over asexualreproduction. Sexual reproduction has been responsible for thedevelopment of new species that are in a position to withstand thecurrent environment challenges such as climate. Evolutionaryadvancement requires species or organisms that are well equipped andadapted to the environment (Schön et al., 2009). Sexualreproduction is the pillar of evolutionary advancement since it leadsto the development of organisms that are well suited to the currentenvironment that has come up as a result of evolution. Sexualreproduction enables the production of recombinant types of organismsthat are able to survive in a challenging environment. Additionally,recombinant species are said to have the ability to eliminate harmfulmutations in a single death. This is extremely essential forevolution and therefore sexual reproduction acts as the pillar forevolutionary advancement (Schön et al., 2009). It is also essentialto mention that sexual reproduction brings along a big pool oforganisms hence increasing the chances for survival.

Sexual reproduction has a number of advantages over the asexualreproduction. Sexual reproduction has the ability to producevariations in genetics hence produce organisms with survival tacticsthat enable them to survive in harsh conditions. It is evident thatevolution has led to various environment changes that require specieswith special features in order to survive in such environments(Schön et al., 2009). Due to the various changes in the environmentas a result of evolution, the number of species produced must benumerous in order to increase the chances of survival. Sexualreproduction helps in that it leads to production of numerous speciesand therefore increases the chances and the numbers of survivors(Barrett, 2008). Sexual reproduction may be slow, but it leads toquick evolution. Lastly, sexual reproduction has been known to havevery low rates of extinction.

Research has indicated that the Down`s syndrome is mainly common inbabies that are born of women older than 35 years. It is a conditionthat can be detected before or after birth through various screeningtechnologies. The condition leads to cognitive and physicaldevelopment impairments. Down`s syndrome is caused by the existenceof 47 chromosomes instead of 46 in a cell. Meiotic non-disjunction infemale eggs increases with age. Women under the age of 30 have a verylow likelihood of having non-disjunction in their eggs. However,women older than 35 years have high chances of having meioticnon-disjunction of the eggs. Research has indicated that older eggsin women have high chances of or risks of improper chromosomedivision (Sloane, 2009). Besides the issue of the age of the mother,it is evident that there might be other factors that might lead toDown’s syndrome. If one of the parents, either the mother or thefather is a carrier, there is an extremely high likelihood that thechild will have Down’s syndrome.

Whereas women over the age of 35 are the ones expected to have ahigh rate of children with Down’s syndrome, research has shown thatwomen under 30 have had an extremely high number of children withDown’s syndrome. This has been attributed to the fact that womenunder 30 are having more children than women over the age of 35(Gordon, 2013). It is also essential to remember that women who havehad children with Down’s syndrome have an extremely high chance orrisk of giving birth to children with this condition. It is said thatthe likelihood is 1 in a 100.

References

Schön, I., Martens, K., &amp Dijk, P. (2009).&nbspLost sex:The evolutionary biology of parthenogenesis.Dordrecht: Springer.

Barrett, S. C. H. (2008).&nbspMajor evolutionary transitions inflowering plant reproduction. Chicago: University of ChicagoPress.

Sloane, E. (2009).&nbspBiology of women. Albany, N.Y: Delmar.

Gordon, J. W. (2013).&nbspThe Science and Ethics of Engineeringthe Human Germ Line. New Jersey: John Wiley &amp Sons.