Science – Unit 4

Science- Unit 4

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Science- Extra Credit

  1. What different evolutionary stages has a horse been through before becoming what we know now a days? What are the physical differences in each stage?
  2. What is one of the suggested reasons why people believed dragons and giants existe?
  3. What is Charles Lyell’s book “Geology’s principals” about?
  4. From what latin word is the word fossils derived?
  5. What is a fossil?
  6. What explanation do geologists give about extinct species from the past?
  7. What is stratification?
  8. How does a fossil’s location help an investigator to learn about different species?
  9. What is the name for fossilized feces?
  10. What is Charles Darwin’s book On the Origin of Species (1859) say?
  11. What is extinction?
  12. Why do you think fossils are important in order to understand different species?

Geography with answers

  1. What is an ecosystem? An ecosystem is a community of plants, animals and smaller organisms that live, feed, reproduce and interact in the same area or environment. Some ecosystems are very large. For example, many bird species nest in one place and feed in a completely different area.
  2. How are ecosystems formed?

An ecosystem includes all of the living things (plants, animals and organisms) in a given area, interacting with each other, and also with their non-living environments (weather, earth, sun, soil, climate, atmosphere).

3. What does the term “biotic” mean?

Biotic, meaning of or related to life, are living factors. Plants, animals, fungi, protist and bacteria are all biotic or living factors.

4. What does the term “abiotic” mean?

The term abiotic refers to the non-living or physical components of an ecosystem.

5. What is extinction? Why does it happen?

Extinction occurs when the last existing member of a given species dies.
In other words…there aren’t any more left!
It is a scientific certainty when there are not any surviving individuals left to reproduce.

Climatic Heating and Cooling

Climate Change is caused by a number of things. The effect that climate has on extinction is very big. The biodiverse Earth can’t keep up with the rapid changes in temperature and climate. The species are not used to severe weather conditions and long seasons, or a changing chemical make-up of their surroundings. As more species die, it is only making it more difficult for the survivors to find food. The warmer climates we are used to present-day are perfect for diseases and epidemics to thrive.

Changes in Sea Levels or Currents

The changes in sea levels and currents is a result, in part, of the melting freshwater. The denser, saltier water sinks and forms the currents that marine life depends on. Ocean floor spreading and rising also affects sea level. A small rise in the ocean floor can displace a lot of water onto land that is all ready occupied. The gases from the volcanic activity can also be absorbed by the water, thus changing the chemical composition, making it unsuitable for some life.

Asteroids/Cosmic Radiation

Asteroids hit the earth with extreme force. The reverberations can be felt around the world. The impact site is completey destroyed.
Cosmic Radiation is radiation being emitted from outer space and the Sun. It is hypothesized that being exposed to too much cosmic radiation can mutate genes, which can potentially weaken a species’ genepool in the future. Since the radiation comes from space and the Sun, it is extremely difficult to avoid the radiation. Supernova remnants is one source of cosmic radiation.

Acid Rain

Acid rain forms when sulfur dioxide and/or nitrogen oxides are put out into the atmosphere. The chemicals get absorbed by water droplets in the clouds, and eventually fall to the earth as acid precipitation. Acid rain increases the acidity of the soil which affects plant life. It can also disturb rivers and lakes to a possibly lethal level

6. How do different species survive (if they do) when their ecosystem is destroyed?

They look for a new ecosystem and try adapting to it.

7. What is a balanced ecosystem?

The organisms have to fit into the energy pyramid – The largest number of organism in any ecosystem needs to be the producers – The smallest number of organism need to be the highest level of consumers in that ecosystem A balanced ecosystem is an ecological community together with its environment, functioning as a unit.

  • The balance of an ecosystem means that the kinds and the number of organisms are maintained consistently. The kinds and the number of organisms, which compose the ecosystem, are controlled through the relation of eating and being eaten. Even though the balance of an ecosystem is temporarily broken, it is recovered by the force of restitution of the ecosystem.

8. What is a diverse ecosystem?

Ecosystem diversity refers to the assortment of a place at a rank of ecosystems. Diversity is important to an ecosystem because, through increasing species diversity within an ecosystem, the efficiency and productivity of that ecology will increase.

9. What elements are needed in order to make an ecosystem survive?

10. How can an ecosystem support various types of organisms?

Because of it’s carrying capacity.

11. What does the term carrying capacity mean?

The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment. In population biology, carrying capacity is defined as the environment’s maximal load, which is different from the concept of population equilibrium.

12. What determines if a population survives within an ecosystem?

If the ecosystem provides the population’s needs it will survive.

Within each ecosystem, there are habitats which may also vary in size. A habitat is the place where a population lives. A population is a group of living organisms of the same kind living in the same place at the same time. All of the populations interact and form a community. The community of living things interacts with the non-living world around it to form the ecosystem. The habitat must supply the needs of organisms, such as food, water, temperature, oxygen, and minerals. If the population’s needs are not met, it will move to a better habitat. Two different populations can not occupy the same niche at the same time, however. So the processes of competition, predation, cooperation, and symbiosis occur.

  • Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another.
  • In ecology, predation describes a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked).
  • Cooperation is the process of groups of organisms working or acting together for their common/mutual benefit, as opposed to working in competition for selfish benefit.
  • symbiosis _A close, prolonged association between two or more different organisms of different species that may, but does not necessarily, benefit each member.

13. What are the main non-living parts of an ecosystem?

Abiotic factors are the non-living factors in an ecosystem that effect the survival of organisms in the ecosystem. Light, temperature, and atmospheric gases are the examples of Abiotic factors. Another example would be a forest fire.

14. What is a food web?

A food web is a series of food chains. A food chain is a linear sequence of links in a food web starting from a trophic species that eats no other species in the web and ends at a trophic species that is eaten by no other species in the web.

15. What is a food chain?

A food chain is a linear series of links starting with one specific species that eats no other species in the web, and ending with a specific species that eaten by no other species in the web. That’s different from a food web.

16. What does the term catastrophic mean?

It comes from the word “catastrophe”, which means a disaster. Catastrophic means disastrous. A catastrophe is the kind of disaster that destroys the people it happens to.

17. What makes a tropical rain forest different from any other ecosystem?

Tropical rain forests grow in regions with plenty of moisture and heat. They are also referred as ‘evergreen forests’.

Because of the lack of seasonal differences, due to the geographical location of the forests, and the high humidity level the vegetation is luxuriant here. The recurring features of rainforests are basically the following:
• high animal and vegetal biodiversity
• evergreen trees
• sottobosco buio e spoglio, intervallato da radure
• dark and sparse undergrowth interspersed with clearings
• scanty litter (organic matter settling on the ground)

18. What is a stable ecosystem?

The stability of an ecosystem implies that the ecosystem can survive over time.

The Principles of Ecosystem Stability are:

  • Ecosystems dispose of waste and replenish nutrients by recycling all elements.
  • Ecosystems use sunlight as their source of energy.
  • The size of a consumer population is maintained such that overgrazing and other forms of overuse do not occur.
  • Biodiversity is maintained.

Factors influencing ecosystem stability are biotic potential and environmental resistance. This could be in the form of: positive and negative factors of population growth either abiotic or biotic, species diversity that is highly correlated with stability, as well as climate.

Stability of an ecosystem also needs to have a resistance to change. This resistance to change has three forms: Inertia – the resistance to change, Resilience – the ability to recover from change and succession – the replacement of species by another.

19. What is flora?

Flora denotes the plant life in a particular region.

20. Describe the roll of a producer in an ecosystem.

Ecosystem producers are capable of producing their own food. Plants manufacture their own food by the process of photosynthesis and also produce food for other consumers in the ecosystem. Plants as producers also give us oxygen.

In an ecosystem, producers are those organisms that use photosynthesis to capture energy by using sunlight, water and carbon dioxide to create carbohydrates, and then use that energy to create more complex molecules like proteins, lipids and starches that are crucial to life processes. Producers, which are mostly green plants, are also called autotrophs.

Producers funnel into the ecosystem the energy needed for its biological processes. The carbohydrates and other organic chemicals formed by the producers are consumed and utilized by the heterotrophs, or consumers; first by the herbivores who eat the plants–the primary consumers–then by the predators who eat the herbivores–the secondary, tertiary, and so on consumers.

21. Describe a desert; include details like temperature, living organisms and their characteristics.

Desert plants are different from plants in other ecosystems because they have to live and grow with very little water. Plants have shallow roots so that they can soak up any rain that falls in this dry environment. Plants store water in their stems and have sharp needles that keep animals from eating them to get their water. Most desert animals are nocturnal, that means they hunt for food at night when it’s cooler. Many desert animals fur, feathers, or skin is light in color because the light color reflects the hot desert sun.

22. Explain how humans damage ecosystems; consider the effects and conflicts may arise.

An ecosystem is an area where all the species of plants and animals live and depend on each other. Ecosystems are often delicately balanced, and if that balance is damaged, the results can be unpredictable. People have changed the balance in many ecosystems around the globe, sometimes leading to detrimental consequences.

Over-Hunting

  • People have greatly accelerated extinction rates among animals through over-hunting. Once a species is gone, that unbalances the ecosystem that it comes from, and it can cause a chain reaction of extinctions or population reductions.

Habitat Destruction

  • People chop down forests for farming and building homes. They also drain wetlands for the same purposes or to irrigate crops. These activities ultimately lead to additional extinction events because it reduces the amount of land available to support different species.

Pollution

  • Human industrial society releases a lot of different pollutants into the air. Pollution can damage both plant and animal species and eventually reduce their populations. It can also make certain areas of the planet uninhabitable for many species.

Geography Questionnaire

  1. What is an ecosystem?
  2. How are ecosystems formed?
  3. What does the term “biotic” mean?
  4. What does the term “abiotic” mean?
  5. What is extinction? Why does it happen?
  6. How do different species survive (if the do) when their ecosystem is destroyed?
  7. What is a balanced ecosystem?
  8. What is a diverse ecosystem?
  9. What elements are needed in order to make an ecosystem survive?
  10. How can an ecosystem support various types of organisms?
  11. What does the term carrying capacity mean?
  12. What determines if a population survives within an ecosystem?
  13. What are the main non-living parts of an ecosystem?
  14. What is a food web?
  15. What is a food chain?
  16. What does the term catastrophic mean?
  17. What makes a tropical rain forest different from any other ecosystem?
  18. What is a stable ecosystem?
  19. What is flora?
  20. Describe the roll of a producer in an ecosystem.
  21. What determines if a population survives within an ecosystem?
  22. Describe a desert; include details like temperature, living organisms and their characteristics.
  23. Explain how humans damage ecosystems; consider the effects and conflicts may arise.