1. | the loss of unnecessary sense organs |
2. | presence of adhesive organs or suckers to cling on to the host |
3. | loss of digestive system |
4. | low reproductive capacity. |
1. | dN/dt = rN[1- N/K] | 2. | dN/dt = rN[1- K/N] |
3. | dN/dt = rN + [1- N/K] | 4. | dN/dt = rN + [1- K/N] |
1. | differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species' distributions do not overlap. |
2. | two species which compete for the same limited resource cannot coexist at constant population values. |
3. | there is an expansion of the range of a species when a competitor for its niche is removed. |
4. | there is a division of limited resources by species to help avoid competition in an ecological niche. |
1. | Flamingoes visiting American lakes and resident fishes: Commensalism |
2. | Yucca plant and Tegeticula yuccasella, the yucca moth: Mutualism |
3. | Female Anopheles and humans: Parasitism |
4. | Lichens: Predation |
1. | the number of individuals in the pre-reproductive age group are more than the number of individuals in the reproductive age group. |
2. | the number of individuals in the reproductive age group are less than the number of individuals in the post-reproductive age group. |
3. | the number of individuals in the reproductive age group are equal to the number of individuals in the reproductive age group. |
4. | the number of individuals in the pre-reproductive age group are less than the number of individuals in the reproductive age group. |
1. | It is necessitated by nature to maintain the ecological balance . |
2. | It helps in maintaining species diversity in a community. |
3. | It might lead to the extinction of a species. |
4. | Both the interacting species are negatively impacted. |
While explaining interspecific interaction of population, (+) sign is assigned for beneficial interaction, (–) sign is assigned for detrimental interaction and (0) for neutral interaction. Which of the following interactions can be assigned (+) for one species and (–) for another species involved in the interaction?
1. Competition
2. Predation
3. Amensalism
4. Commensalism