(a) (i) - Taxis and kinesis allows individuals to associate their environments with a stimulus such as light, temperature, pH, etc.- The environment may create conditions that the individual

would rather spend more time in finding shelter rather than practicing courtship.

(ii) Taxis and kinesis increases an individual’s alertness of their surroundings and will initiate a faster response against predators, towards food sources, etc.

(b) Curve A depicts the population density of a large herbivore. This is relatively stable as these animals would be in the center of the food chain. They will have enough food and the strength to combat some predators. Curve B reflects a small herbivore whose population starts out very large (many eggs) but quickly decreases due to being overcome by predators. Curve C shows a carnivore – these animals are born in smaller amounts but are closer to the top of the food chain. Their longer lives allow them to die off after old age as a new wave comes in.

(a) - Bacteria can be a producer as it converts carbon into O2 during photosynthesis. This allows energy for the rest of the ecosystem. - Bacteria can also act as a parasite inflicting upon its host

through disease (aka pathogen), causing a +/- relationship. This means that population size can be regulated, balancing the entire ecosystem.

- Bacteria is a decomposer as it clears out dead waste. Otherwise these nutrients wouldn’t be recycled and our ecosystem would be polluted.

(a) As the forest evolves, conditions will become more suitable for more species and more habitats will be created. There will also be more food sources available and the consumers will be able to establish more of a diverse diet.

(b) The soil will become much richer with organic matter, allowing a larger retaining of water. Light and temperature will decrease

due to shading, so certain species can live within the cooler environment. Humidity will also increase due to more transpiration – the evaporation of plants.

(c) – Volcano: In the short term, no soil will exist. In the long term, the lava will dry up and allow fungi to form. Light will eventually attract organisms to live there.- Deforestation: In the short term, soil will exist and not every

life will be killed. In the long term, there may be erosion but species will return once the succession of plants grows.

(a) Energy flows through the ecosystem by a process called photosynthesis. During this process, sunlight is converted into cellular energy to be used by individuals. When smaller individuals are eaten by larger ones, the energy transfers through all trophic levels.

(b) – Deforestation: More CO2 will be released into the atmosphere because trees will not be there to absorb the excess. These trees are also primary producers, and will not be able to act as food for higher levels of individuals. This will disrupt the ecosystem. Habitats will be destructed not only for those who live in the trees, but also those who lived in the trees’ shade or cooler temperatures.- Global climate change: The number of producers will change,

as will the amount energy and respiration. Ecosystems will be replaced with less productive ones, as individuals attempt to survive meanwhile adjusting to the new environments.

(a) Species C is experiencing exponential growth because are very well fit for survival in their environment. They have no predators, lots of food, and beat out their competitors.

(b) Species C may have overpowered species B. According to the Competitive Exclusion Principle, two similar species using the same resources will not be able to live together. One must gain dominance and eliminate the other. Species C seems to not have affected species A because they are not battling for the

same foods and shelters. Their environment requirements are completely different and do not interact with each other much.

(c) In 2014, the population may stabilize itself. The area should hit its carrying capacity and there will only be enough resources for a certain number of individuals.

(d) Invasive species are successful in colonizing in new places because they have no predators. They may have an abundant food source and not much competition for it. They have strong successes with finding mates and reproducing more individuals to join their thriving community.

(a) During Phase A, the population is going through exponential growth. Their numbers are rapidly rising. They could be successful in a new habitat with no predators or lots of food.

(b) Phase B has fluctuations because it is now beginning to reach its carrying capacity. When the population goes over, it is affected by the repercussions of crowdedness or lack of food left. It may also suffer from natural disasters including fire, flood, etc.

(c) R-traits are when an animal gives birth to many offspring but many die soon after birth. K-traits are when an animal gives birth to a few offspring but they survive a long life. R traits appear to be less stable in the overall population due its lack to defend of predators or lack of strength to find food. K-traits are much more stable and can provide for themselves for a longer amount of time.