Directions
read the instructions for this self-checked activity. type in your response to each question, and check your answers. at the
end of the activity, write a brief evaluation of your work,
activity
many farmers and gardeners compost their plant and animal waste. the living material naturally decays in compost bins,
forming a dirt-like substance that's rich in nutrients. the next season, farmers use this substance as a natural fertilizer for
their crops
a biology student has grown tomato plants for several years. until now, he used an artificial fertilizer formulated for
tomato plants. this fertilizer caused his plants to grow faster and taller than they grew in unfertilized soil. the student
wants to know whether using natural compost will cause his tomato plants to grow faster and taller than his artificial
fertilizer
answer the following questions to plan an investigation using the steps of the scientific method and the student find
the answer to his question,
part e, how would you conduct your investigation? in your answer, explain your independent and dependent variables.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs