A student is sitting in his canoe on a lake and wants to move the canoe forward. He moves his arms front and back on the handle of the paddle to propel the canoe forward. Then the
student wants to stop the canoe. He stops paddling and the canoe slows. He takes his
paddle and drives it in the shallow bed of the lake to anchor the paddle which stop the
canoe from moving.
Which of these best identifies a pathway of systems in the rider’s body, as described in this
scenario?
A. nervous system → musculoskeletal system → circulatory system → nervous system
B. nervous system → musculoskeletal system → nervous system → musculoskeletal system
C. musculoskeletal system → circulatory system → musculoskeletal system → nervous system.
D. musculoskeletal system → nervous system → circulatory system → musculoskeletal system

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

When listening the levels of orginization in orginisims from the smallest to most complex , which level is just below organs in complexity