Question

6. How does parapatric speciation differ from peripatric speciation? In which form is genetic drift more likely to be important? Why?

7. Provide a phylogeny that has four branches and three nodes and that includes the following taxa: Archaea, Bacteria, “the prokaryotes”, Crenarchaeota, Euryarchaeota, “gram + bacteria”, and “gram – bacteria.” Name all three nodes on this phylogeny

8. Describe why it has been suggested that Crenarchaeota are the most abundant organisms on Earth

9. Name two characteristics that suggest that Fungi are closer to Animalia than to Plantae.

10. Describe the haplodiplontic life cycle. To help you, make sure you have these terms in your description: haploid, diploid, mitosis, meiosis, sporophyte, gametophyte, spore, and gamete.

Answer 1

Ans.7.Allopatric speciation occurs when two species are living in separate environments and therefore there is no gene flow between the populations. This will then cause the populations to differentiate (change) because they will become adapted to the different environments and niches they are living in.

Sympatric speciation occurs when two species are living in the same environment. This speciation is a little more difficult to understand because the species have the occupy the same niche, however it may come down to some barriers (pre-zygotic or post-zygotic) that prevent gene flow, for example mating at different times of the day.

For allopatric speciation ,genetic drift will be important. When populations become separated, gene flow between them ceases. Over time, the populations may become genetically different in response to the natural selection imposed by their different environments. If the populations are relatively small, they may experience a founder effect: the populations may have contained different allelic frequencies when they were separated. Selection and genetic drift will act differently on these two different genetic backgrounds, creating genetic differences between the two new species.

Ans.9)both fungi and animals have-

• Cell wall made of chitin (insects).
• Glycogen as a food reserve.