Science, life functions and characteristics of life questions 10 points!?

Question

i need the answer for this questions! its urgent! answer in one or 2 sentences!

1. Why must foods be digested?

2. why do complex organisms need transport systems?

3. what is the purpose of respiration in living organisms?

4.how are the processes of synthesis and assimilation related?

5. how do living things grow?

6. where do wastes come from?

7. how do the nervous, endocrine, and excretory systems contribute to homeostasis in animals

8. in what way is reproduction important to living organisms?

10. what is metabolism?

if you know any of the answers please tell me! thanks alot!

Answer 1

1.  Food must be digested so we can use the energy stored in it to run our bodies.

2.  A transport system (usually the circulatory system) is required because the food we digest in the digestive system needs to be moved to all the cells that require energy, oxygen needs to be moved to the cells that are active, and carbon dioxide and wastes removed from them.  Larger, more complex animals need the transportation system because diffusion is not an adequate means of moving all that needs to be moved.

3.  There are two types of respiration: cellular respiration, and whole body respiration.  Whole body respiration functions in the exchange of gases: we take up oxygen and release carbon dioxide.  In cellular respiration, each cell "burns" glucose in the presence of oxygen to release its energy, and uses it to make ATP, with the by-product being carbon dioxide.

4.  In assimilation, an organism takes outside resources and makes them part of itself.  Synthesis can mean many different things; in general, it is considered to be "a process which combines together two or more pre-existing elements resulting in the formation of something new."

5.  Living things grow in a manner directed by their DNA.  Generally, excess energy/resources from food not used in the ordinaty "running" of the animal's body (metabolism) is stored and used for growth.

6.  Wastes are the by products of the processes necessary for life.

7.  Homeostasis is the maintenance of a relatively stable internal environment.  The excretory system collects and eliminates wastes so they don't accumulate in the body.  The nervous and endocrine system are involved in cell-to-cell communication, and often function in negative feedback loops to make dynamic equilibrium adjustments to the body.

8.  Reproduction is important for the continuance of each species; in genetic terms, the more an organism contributes to the gene pool of the next generation, the more "successful" it is.

9.  ?

10.  Metabolism is "the set of chemical reactions that occur in living organisms in order to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments."

Most of these answers are available in your textbook and/or on internet sites.  Try using Wikipedia for simple definitions, and google for more complex questions.  

Answer 2

1.  For the food to be utilized by the organism else, the nutrients could not feed the whatever.

2.  Complex organisms need nourishment to reach all of their cells

3.  Respirationis to get Oxygen to the cells and the waste products out of the system.

4. Both take basic elements and use them to make something.

5.  Through the process of growth, major component of living

6.  Wastes are the by product of respiration, and digestion

7. Through responding to stimuli, they maintain balance.  (kind of hard to answer in a sentence or two)

8.  Without reproduction after a generation they'd die out.

9.  Metabolism is the sum of all energy used by an organisms

Answer 3

1. To make molecules small enough to be taken up by the blood and to enter the cells.

2. In complex organisms the body layers are thick and the required molecules cannot reach all the cells by diffusion. Thus a transport system takes it where it is required.

3. Respiration produces energy (ATP) required for cell activities.

4.Assimilation: external molecules becomes part of the cell.

   Synthesis: internal molecules are combined to build a new  

   substance.

5. Cells divide through mitosis.

6.Excretory wastes are made by the body.(sweat, urine,  

  carbon dioxide)

   Egestive wastes are digestive left overs.  (faeces)

7. endocrine system secretes hormones which control chemical

   homeostasis.

  Excretory system balances oxygen, carbon dioxide,water, salt and pH of blood.

8. reproduction prevents extinction of an organism.

9. All the reactions taking place in a living cell. There are 2 types:

   anabolic  : building up  ( eg.synthesis)

   catabolic : breaking down ( eg.respiration)