What is the difference between allopatric and sympatric speciation? Give examples of each.
Allopatric speciation occurs when a population is separated by geographical barriers. This causes a reduction in the changes of interbreeding amongst these individuals. Mutations occur and each population may adapt to the new environment. After a long time the populations evolve into two distinct and separate species. It is the most common form of speciation. Example: A single ancestor species of finch emigrated to various Galapagos islands. The now separated populations were geographically and thus reproductively isolated. Mutation led to changes in the finch beaks that allowed them to consume the specialized seeds on each of the islands. Eventually, the populations were so physiologically different that they were considered different species. Sympatric speciation is the formation of two or more species that occupy the same geographical area. These species originated from a common ancestral species. There is no geographical barrier separating these species. This is a rare type of speciation. Example: apple maggot flies have two sources of food: Hawthorne or apples. Over time some flies prefer (or are closer to) hawthorns while others may prefer or have more access to apples. Their dietary differences lead to occupation of separate plants and the breeding of individuals where these plants are leads to speciation.
Explain the components of the following as found in both a prokaryotic and eukaryotic cell: a. DNA b. Organelles c. Reproduction d. Size difference (larger, smaller)
a. Prokaryotic: DNA is not bound by protein, DNA is circular, usually there are no introns EukaryoticL DNA is protein bound, DNA is linear, usually, there are introns b. Prokaryotic: no nucleus, organelles are not membrane-bound, 70s ribosomes Eukaryotic: nucleus, organelles are membrane-bound, 60s ribosomes c. Prokaryotic: reproduction occurs by binary fission, produces a single chromosome (haploid) Eukaryotic: reproduction occurs by mitosis, produces paired chromosomes (diploid or more) d. Prokaryotic: smaller Eukaryotic: larger
Using the data set 6, 3, 10, 7, 11, 6, 8, 10, 2 a. Find the median b. Find the mode c. Find the mean d. Find the sample standard deviation e. If the value 3 from the list above is replaced with a new data value, 22, how will the standard deviation change (increase, decrease, stay the same)?
a. 7 b. 6 and 10 c. 7 d. 3.122 e. The standard deviation of the sample will increase because 22 is further from the other data values than 3 is