Temperature
organisms vary in terms of their needs towards the environment,
organisms are adapted to the conditions of their natural habitat.
to describe how temperature influences organisms.
Temperature has a major impact on the activity of organisms. Enzymes and neurotransmitters that are responsible for biochemical reactions in cells work best in a precisely defined temperature range. Therefore, for organisms to engage in all life activities they need the right temperatures. A perfect example of this are cold‑blooded animals such as reptiles and amphibians which are quick and active on warm days and lethargic and apathetic when it's colder. That is why so few animals belonging to these animal classes can be found in higher latitudes.
Perishable food, such as slices of ham, needs to be kept in a fridge. Explain why bacteria and fungi that can be found on the surface of the ham would make it go bad much quicker at room temperature than in the fridge.
In the water environment changes in temperature are not significant. On land, however, this is quite the opposite: extremely low and extremely high temperatures can cause dehydration and overheating of organisms, and water freezing in their tissues, creating ice crystals, can damage cell membranes. Such effects of extremely low or high temperatures can be deadly to organisms. In order to survive in the unfavourable conditions, many animals take advantage of hibernationhibernation or aestivationaestivation. These states are similar physiologically and are characterised by much slower vital function rates of the organism. The animal's heart rate, metabolism and respiration rate decrease. While dormant, they don't move much so they use little of oxygen and their energy reserves. This is a strategy aiming at survival when there is no food or water (which is indirectly related to too low or too high temperatures).
Plants have also adapted in numerous ways in order to survive periods of time with unfavourably high or low temperatures.
Plants protect themselves against frost by means of thermal insulation (thick bark of trees, leaves wrapped around young buds in the spring, underground wintering of perennial plants) and by developing mechanisms to prevent water from freezing in cells (higher concentration of glucose in the cellular juice). Protection from too high temperatures can be provided by the insulation layer (such as tree bark), light reflection mechanisms (such as a layer of wax on the leaves of tropical plants), higher transpiration rates or other reactions such as turning or curling of the leaves. Particularly resistant to temperature changes are forms designed to assure the survival of the plant, namely the seeds.
Check how much time is needed to freeze a slice of a frankfurter in comparison to freezing the whole sausage. Afterwards, take them both out of the freezer and check how much time it takes to defrost the slice and the whole frankfurter. Using this data, explain how the size of an animal impacts its ability to maintain stable body temperature.
In too low or too high temperatures the organisms' food and water supply is scarce. Therefore, some animals engage in animal migrationanimal migration twice a year which involves simply travelling to warmer or cooler parts of the globe. The factor that triggers animal migration (and also hibernation and aestivation) is not only temperature itself, but also the length of the day. The best known and most spectacular migrations are those of birds which move in flocks of even tens of thousands of birds. In our climate, the birds that migrate for winter are mainly small insect‑eating birds with huge energy expenditure in comparison to their body mass. On the other hand, the birds that come here for winter are plant‑eating birds, such as bullfinches, Bohemian waxwings, bramblings and rough‑legged buzzards which are birds of prey. A truly remarkable example of a migrating bird is the bar‑tailed godwit which can fly for more than 11 thousands kilometres without a single landing.
To survive the winter, the amount of food a great tit needs to eat equals its body mass. The necessary daily food intake of a lynx constitutes a 10–15% of its body mass. Explain the reason for such difference.
Indicate all the ways extremely high temperatures can affect the organism.
- dehydration
- overheating
- body shivering
- sunburn
Assign elements to the appropriate groups.
the animal wakes up when temperature drops below a certain threshold, also called winter dormancy, the animal goes dormant when temperatures go above a certain threshold, the animal goes dormant when temperatures go below a certain threshold, this is to reduce the need for water and food which are scarce due to too high temperatures, also called summer dormancy, this is to reduce the need for water and food which are scarce due to too low temperatures, the animal wakes up when temperature rises above a certain threshold
| aestivation | |
|---|---|
| hibernation |
Which factor, besides temperature, is a trigger for migration for some animals?
- amount of rainfall
- atmospheric pressure
- length of day
- strength and direction of the wind
Summary
Temperature in the habitat has an impact on the activity of organisms.
Keywords
temperature, aestivation, hibernation
Glossary
sen letni – inaczej estywacja; spowolnienie procesów życiowych w okresie letnim, mające na celu ograniczenie zapotrzebowania na wodę i pokarm, których brakuje z powodu wysokich temperatur
sen zimowy – inaczej hibernacja; spowolnienie procesów życiowych w okresie zimowym, mające na celu ograniczenie zapotrzebowania na wodę i pokarm, których brakuje z powodu niskich temperatur
wędrówki migracyjne – wędrówki powtarzane w stałym cyklu rocznym podejmowane przez niektóre zwierzęta w poszukiwaniu pokarmu