What is the effect of diurnal turnover on biological activity?

Plant growth in a certain period of time presents a slow, fast and slow rhythm, this fast and slow rhythm is related to the seasons and diurnal changes, the growth rate of plants or organs changes regularly with the change of day and night or seasons, this phenomenon is called the cyclical nature of plant growth. From the definition, it can be seen that the cycle of plant growth can be divided into diurnal periodicity and seasonal periodicity.

a) Circadian periodicity.

The regular change in plant growth with the alternation of day and night is known as the circadian periodicity. With the alternation of day and night, light, temperature, and moisture also change periodically, which affects the growth rate of plants. Plant growth rate can be expressed in two ways, one is measured by the amount of dry matter accumulated and the other is measured by plant height or volume.

If the dry matter accumulation is taken as the index, the growth rate during the day is greater than that at night, and if the plant height, fresh weight, or volume is used as the index, the growth rate shows three changes with the alternation of day and night, 1) under the condition of sufficient moisture, the daytime light is sufficient, the temperature is suitable, and the growth rate is greater than that at night.

2) When the light is too strong during the day and the temperature is high, the transpiration is too strong, the water loss is more, the water deficit in the body occurs, and the growth is inhibited, and the growth rate during the day is less than that at night.

3) When daytime and nighttime temperatures are similar, daytime and nighttime growth rates are similar.

The circadian cycle of plant growth is not only affected by the alternation of day and night, but also by the endogenous mechanism of plants—the biological clock.

the influence of the regulation.

2) Seasonal periodicity.

The regular change of plant growth with the change of seasons is the seasonal periodicity of plant growth. Because.

It causes seasonal changes in sunshine length and temperature, which in turn affect the growth of plants, so that the growth of plants changes regularly. to perennial.

For example, in spring, the temperature rises, the light gradually increases, the plant begins to grow, and the summer grows vigorously, due to the higher sunshine, the sunshine is longer and stronger, and in the autumn, the sunshine gradually shortens, the temperature decreases, the growth is inhibited, and it enters a dormant state, and the winter growth completely stops and is in a dormant state. This change.

Years. c) Biological clock.

The biological clock refers to the internal control mechanism of physiological activities formed by plants in the long-term evolution process with the alternation of day and night. The circadian clock is the endogenous timing system of living things. The chronological period of the biological clock is approximately 24 hours.

Hence the also known as approximate circadian rhythm. Plant growth, movement,

Plants: photosynthesis, respiration and transpiration during the day, respiration at night; The growth, flowering and fruiting of plants are affected by light and temperature, and plants can perceive the difference between day and night and physiological changes will occur accordingly. Animals:

Day and night affect the activities of animals, including foraging activities, breeding activities. Some animals forage during the day, and there are more such animals, such as lions, tigers, dogs, etc.; Some animals like to forage at night, such as mice, some snakes, owls, etc. Light temperature affects animal reproduction, for example, canaries generally reproduce from November to July of the following year.

Of course, the change of day and night also has an impact on biological activities, because during the day, the sun rises high, which can give the earth a full bloom of plants, and it is also well exposed to sunlight.

The cycle of day and night causes animals to produce a circadian clock pattern (e.g., rats) or nocturnal (e.g., humans and many other mammals), and human life is affected by the cycle of day and night. For plants, the exchange of day and night is also a process of energy or sugar production, release, aggregation and utilization, and this impact on plants will also indirectly affect animals. <

The cycle of day and night causes animals to produce a circadian clock pattern (e.g., rats) or nocturnal (e.g., humans and many other mammals), and human life is affected by the cycle of day and night. For plants, the exchange of day and night is also a process of energy or sugar production, release, aggregation and utilization, and this impact on plants will also indirectly affect animals.

1.The effect of the alternation of day and night on living things.

The cycle of day and night has given animals a circadian clock pattern (e.g., rats) or nocturnal (e.g., humans and many other mammals), and our lives are affected by the cycle of day and night. For plants, the alternation of day and night is the process of energy or sugar production, release, aggregation and utilization (for example, grapes will photosynthesize to produce energy during the day, and respiration to release energy at night; During the day, sugar is consumed to survive. At night, energy is built up for tomorrow), and this effect on plants also indirectly affects humans.

2.The effects of seasonal changes on living things.

1) Influence on plants: such as a hundred flowers blooming in spring, rapid growth of plants in summer, fruitful fruits in autumn, dormancy (deciduous leaves) of plants in winter and Nabo season, etc., "sleeping" until the next spring before germination and growth.

2) Impact on animals: Some animal life changes regularly with the four seasons, such as hairy-footed bees feeding on nectar in spring, breeding offspring in summer, building nests and storing winter food in autumn, and hiding in nests in winter. Some animals also migrate or hibernate in rotation depending on the seasons, such as geese and hedgehogs.

3) the impact on humans; Farmers plant, care for, and harvest crops according to the seasons, and people change their clothes according to the seasons.

Most plants sprout and grow in the spring when temperatures begin to rise, followed by flower buds: flowering and fruiting in summer and autumn heat; In late autumn, the leaves fall at low temperatures, and then go into dormancy. This stage of growth and development, such as germination, growth, emergence of flower buds, flowering, fruiting, defoliation, and dormancy, is called phenological stage.

The phenological period is a true and accurate reflection of the comprehensive climatic conditions (especially temperature) of each year, and it is used to predict agricultural time, pest emergence period, etc., which is more accurate than the average temperature and season.

Phaseolus vulgaris leaves are horizontal during the day and droop at night, which is called sleep, such as continuous light or continuous darkness of Phaseolus vulgaris, and keep the temperature constant, Phaseolus vulgaris leaves are still flat during the day and drooping at night, indicating that the sleeping motility receptor of Phaseolus vulgaris is controlled by an endogenous mechanism, which is the biological clock. An important feature of the biological clock is that it can be transferred, and the main factor in the allocation of the biological clock is light. Therefore, the cycle of the circadian clock is always approximately 24 hours.