Animal And Plant Orientation

Auxin is the main plant hormone involved in phototropism. Phototropism is the growth or movement of a plant in response to light. Auxin is responsible for promoting cell elongation on the shaded side of the plant, causing it to bend towards the light source. This hormone is produced in the plant's shoot tips and is transported downwards towards the shaded side, where it stimulates cell growth and elongation. Therefore, auxin plays a crucial role in the directional growth of plants towards light, making it the main hormone involved in phototropism.

Crepuscular is the correct answer because it refers to animals that are most active during twilight, which includes dawn and dusk. This term is commonly used to describe animals that have adapted to low-light conditions and have specific behaviors and adaptations that allow them to thrive during these times of the day.

A biological rhythm that lasts for 12.4 hours would be circatidal. Circatidal rhythms are biological rhythms that follow the tidal cycle, which typically occurs every 12.4 hours. These rhythms are commonly observed in organisms living in intertidal zones, where they need to synchronize their activities with the changing tides. By having a circatidal rhythm, these organisms can anticipate and prepare for the environmental changes associated with the tidal cycle, such as fluctuations in water levels and availability of resources.

In this relationship, both the fish (Nemo) and the anemone benefit. The fish obtains protection from potential predators by snuggling among the stinging tentacles of the anemone, while the anemone benefits from the fish bringing food to it. This mutual exchange of benefits characterizes a mutualistic relationship.

Zugunruhe refers to the restless behavior exhibited by animals before they migrate. This behavior can include increased activity, restlessness, and heightened alertness. It is believed to be a result of internal biological cues that signal the need to migrate and prepare for the journey. Animals may exhibit zugunruhe by restlessly pacing, flying or swimming in circles, or engaging in other repetitive behaviors. This behavior is observed in a wide range of migratory species, including birds, insects, and fish, and is essential for their successful navigation and survival during migration.

The given correct answer for this question is "negatively geotaxic, negative geotaxic". Geotaxis refers to the movement of an organism in response to gravity. In this case, the mosquito larvae swim down in response to light or shadow, which is opposite to the direction of gravity. Therefore, their response is negatively geotaxic. The term "negative geotaxic" is used to describe this type of response.

This relationship can be classified as commensalism because the remora fish benefits from the relationship by hitching a free ride and feeding on the shark's leftovers, while the shark is unaffected by this interaction.

A biological rhythm that lasts about 14 days would be circasemilunar or circa-semilunar. This term refers to a rhythm that occurs approximately every two weeks. It suggests that there is a regular pattern or cycle in biological processes that follows a 14-day interval. This could be seen in various biological phenomena such as menstrual cycles, sleep-wake cycles, or certain hormonal fluctuations. The prefix "circasemi" or "circa" indicates that the rhythm is not exactly 14 days but occurs around that duration.

Epiphytes are plants that grow on other plants but do not harm or benefit them. This type of relationship, known as commensalism, occurs when one organism benefits while the other remains unaffected. In the case of epiphytes, they obtain support and access to sunlight from the host plant, while the host plant is not significantly affected. Therefore, commensalism is the correct answer for this question.

Polygynandry is an appropriate explanation for the given answer because it refers to a social system where multiple males and females in a group engage in mating with each other. In this system, both males and females have multiple partners and there is no specific pairing or monogamous relationships. It is a form of polygamy where both polygyny (multiple females mating with one male) and polyandry (multiple males mating with one female) are present simultaneously within the group.

During the night, Pr (phytochrome red) is converted to Pfr (phytochrome far-red) by far-red light. During the day, red light converts Pfr to Pr. This means that during the night, more Pfr is being converted to Pr, leading to a decrease in the amount of Pfr. In the morning, plants will have more Pr because Pfr is being converted back to Pr during the night. Therefore, in the morning, plants will have more Pr and less Pfr.