Why do creatures want to survive

Learning Objectives Categorize living organisms and non-living things. Key Takeaways Key Points Living organisms are systems made from cells and are capable of life functions such as reproduction, metabolism, response to stimuli, and homeostasis.

Nonliving things are either living things that have died or inanimate objects that were never alive. The nonliving abiotic components of an ecosystem include energy, oxygen, water, nutrients, and temperature.

Living organisms have ranges of ecosystem conditions where they can perform all physiological functions of life. Organisms cannot perform these functions as well or at all outside of these conditions, but some organisms have developed ways to adapt to environmental changes. Migration and hibernation are two examples of these adaptations. Organisms called extremophiles can assume forms enabling them to withstand freezing, dehydration, starvation, high levels of radiation, and other physical or chemical challenges.

Extremophiles can survive exposure to such conditions for weeks, months, years, or even centuries. All life forms require certain core chemical elements for biochemical structure and function. These include carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur—the elemental macronutrients for all organisms—often represented by the acronym CHNOPS. Key Terms extremophile : A microorganism that can survive in extreme environmental conditions.

Rainforest Trees : Plant growth in the Hoh Rainforest. Survival Needs To sustain human life, certain physiological needs include air, water, food, shelter, sanitation, touch, sleep and personal space.

Learning Objectives Identify the eight minimal physiological requirements for survival. Key Takeaways Key Points While the development of tools, plumbing systems and food preservation have enabled modern man to live life with many creature comforts, the truth remains that the requirements for human survival are quite basic.

Physiological needs include air, water, food, shelter, sanitation, touch, sleep, and personal space. As humans have evolved to interact in community settings, both hunting and gathering in groups, touch—as in a caring caress—is often considered a basic human survival need. In fact, empirical evidence has shown touch to be essential to the early growth and development of healthy humans. Key Terms survival : The fact or act of surviving; continued existence or life. Levels of Organization Living organisms are made up of four levels of organization: cells, tissues, organs, and organ systems.

Learning Objectives Order the levels of organization for living organisms. Key Takeaways Key Points Cells are the most basic unit of life at the smallest level of organization. Cells can be prokaryotic without nucleus or eukaroyotic with nucleus.

The four categories of tissues are connective, muscles, epithelial, and nervous tissues. Organs are made of different types of tissues and perform complex functions. They can be hollow or solid. Organ systems are groups of organs that perform similar functions or perform functions together.

Many physiological functions are carried out by multiple organ systems working in tandem. Key Terms cell : The smallest unit of life capable of independent reproduction. Generally contains nucleic acid, cytoplasm, a cell membrane, and many other proteins and structures. Tissues : A group of similar cells with the same origin that work together to perform the same function. Our effect on the process of evolution even extends to our own species' evolution.

Technology and culture have protected us to a great extent from the selective pressures that drive evolution, allowing many people -- especially those in developed nations who, without medical intervention, would not live to reproductive age -- to pass their genes on to the next generation. Other scientists note that technology and culture have changed but not eliminated the role of natural selection on our species.

We now adapt to crowding, pollution, and new disease rather than the necessity to escape from large predators. Humans will change in the future, but are unlikely to evolve into a new, separate species because no human group is truly isolated anymore, given our transportation systems.

Without genetic isolation, there is no further opportunity for speciation among humans. Learn More The Evolving Enemy. Humans did not evolve from present-day apes. Rather, humans and apes share a common ancestor that gave rise to both.

This common ancestor, although not identical to modern apes, was almost certainly more apelike than humanlike in appearance and behavior. At some point -- scientists estimate that between 5 and 8 million years ago -- this species diverged into two distinct lineages, one of which were the hominids, or humanlike species, and the other ultimately evolved into the African great ape species living today.

Web Activities. About the Project. Site Map. To know more about different types of adaptations visit the link. An animal's environment consists of many different things. The climate, the kinds of food plants that grow in it, other animals that may be predators or competitors- the animal must learn to adapt to each of these factors in order to survive. With increasing population growth and human activity that disturbs the natural habitat, animals must learn to adapt to these kind of threats as well.

Animals in the wild can only live in places they are adapted to. They must have the right kind of habitat where they can find the food and space they need. Visit the link for a brief overview of how animals adapt to their habitat. Did you know that animals camouflage themselves so they can adapt to their environment?

Adaptation can protect animals from predators or from harsh weather. Many birds can hide in the tall grass and weeds and insects can change their colour to blend into the surroundings.

This makes it difficult for predators to seek them out for food.