probability

Examples of probability in the following topics:

• Rules of Probability for Mendelian Inheritance

  • Probabilities are mathematical measures of likelihood.
  • Empirical probabilities come from observations such as those of Mendel.
  • Of the 12 possible outcomes, the die has a 2/12 (or 1/6) probability of rolling a two, and the penny has a 6/12 (or 1/2) probability of coming up heads.
  • It states that the probability of the occurrence of one event or the other, of two mutually-exclusive events, is the sum of their individual probabilities.
  • You should also notice that we used the product rule to calculate the probability of PH and QT and also the probability of PT and QH, before we summed them.

• Mendel's Law of Independent Assortment

  • For more complex crosses, the forked-line and probability methods are preferred.
  • We then multiply the values along each forked path to obtain the F2 offspring probabilities .
  • Rather than writing out every possible genotype, we can use the probability method.
  • The probability for shape occupies the second row (3 round:1 wrinked), and the probability for height occupies the third row (3 tall:1 dwarf).
  • The probability for each possible combination of traits is calculated by multiplying the probability for each individual trait.

• Characteristics of Eukaryotic DNA

  • Eukaryotes, having probably evolved from prokaryotes, have more complex traits in both cell and DNA organization.
  • It is probable that eukaryotic cells evolved from prokaryotic cells.

• The Major Divisions of Land Plants

  • Non-vascular embryophytes probably appeared early in land plant evolution and are all seedless.
  • These early plants were probably most similar to modern day lycophytes, which include club mosses (not to be confused with the mosses), and pterophytes, which include ferns, horsetails, and whisk ferns.

• Present-Time Extinctions

  • Human activities probably caused the Holocene mass extinctions; many methods have been employed to estimate these extinction rates.
  • Estimates of extinction rates are hampered by the fact that most extinctions are probably happening without observation since there are many organisms that are of less interest to humans and many that are undescribed.
  • Lastly, some species are probably already extinct even though conservationists are reluctant to name them as such.

• The Punnett Square Approach for a Monohybrid Cross

  • A Punnett square applies the rules of probability to predict the possible outcomes of a monohybrid cross and their expected frequencies.
  • A Punnett square, devised by the British geneticist Reginald Punnett, can be drawn that applies the rules of probability to predict the possible outcomes of a genetic cross or mating and their expected frequencies.To prepare a Punnett square, all possible combinations of the parental alleles are listed along the top (for one parent) and side (for the other parent) of a grid, representing their meiotic segregation into haploid gametes .
  • Furthermore, because the YY and Yy offspring have yellow seeds and are phenotypically identical, applying the sum rule of probability, we expect the offspring to exhibit a phenotypic ratio of 3 yellow:1 green.

• Early Homo

  • Though the intelligence of these early hominins was probably no more sophisticated than that of modern chimpanzees, the bipedal (two-legged) stature is the key evidence that distinguishes the group from previous primates, who were quadrupeds (four-legged).
  • They probably lived from between 2.5 or 2.3 million and 1.6 million years ago.

• Neurodegenerative Disorders

  • The more prevalent, late-onset form of the disease probably also has a genetic component.
  • One particular gene, apolipoprotein E (APOE) has a variant (E4) that increases a carrier's probability of developing the disease.
  • The disease probably results from a combination of genetic and environmental factors, similar to Alzheimer's disease .

• The Study of Population Dynamics

  • Life tables, which provide important information about the life history of an organism, divide the population into age groups and often sexes; they show how long a member of that group will probably live.
  • the probability of individuals dying before their next birthday (i.e., mortality rate)
  • Birds have a Type II survivorship curve, as death at any age is equally probable.

• Stabilizing, Directional, and Diversifying Selection

  • Assuming the ground is a fairly consistent shade of brown, those mice whose fur is most-closely matched to that color will most probably survive and reproduce, passing on their genes for their brown coat.
  • Mice that carry alleles that make them slightly lighter or slightly darker will stand out against the ground and will more probably die from predation.
  • Medium-colored mice, on the other hand, would not blend in with either the grass or the sand and, thus, would more probably be eaten by predators.