Question

12. Why is defining what a species is so difficult? (3 pts) 13. Describe the three patterns of population dispersion and provide one example of a species that is dispersed in each pattern? (6 pts) 14. What does it mean to be a K-selected species versus an r-selected species? DO NOT JUST DEFINE THE TERMS! (4 pts) 15. A hypothetical population of 10,000 humans has 6840 individuals with the blood type AA, 2860 individuals with blood type AB and 300 individuals with the blood type BB. (6 points) What is the frequency of each genotype in this population? What is the frequency of the A allele? What is the frequency of the B allele? If the next generation contained 25,000 individuals, how many individuals would have blood type BB, assuming the population is in Hardy-Weinberg equilibrium?

Answer 1

12. Answer- A species is defined as a group of organisms which can potentially interbreed among themselves. Since the concept depends on the criteria of reproduction it is difficult to determine if a population of organisms can or cannot reproduce.

13. Answer- The three patterns of population dispersion are-

a) Uniform dispersion - here the individuals of the population are more or less equally spaced. E.g creosote bush.

b) Random dispersion - here the individuals of the population are randomly dispersed. E.g vegetation of flowers.

c) Clumped dispersion - here we found organisms to be clustered in groups. E.g group of elephants

14. Answer-

K-selected species possess the following characteristics-

In comparison to r-selected species, these have quite large body size.

Here populations are relatively stable though the reproductive capacity of the species is very low e.g A population of elephants

r-selected species have the following characteristics-

Body size is relatively small.

Growth rates are very high but have a relatively low probability of surviving to adulthood.  

These species typically exploit less-crowded ecological niches.