Severe depression and bipolar disorder
Plants are producers. The give energy to the herbivores. The gain energy from the sun.
Answer:
- Radial symmetry is advantageous because sessile animals can "sit down", take food, or sense harmful environmental conditions from different directions.
- Bilateral symmetry allows motile animals to move straight forward.
- The major evolutionary advantages of bilateral symmetry include cephalization, the formation of a head and tail area and a more directional motion.
Explanation:
Radial symmetry is advantageous for sessile organisms since it enables the uniform distribution of the sensory receptors around the body. In consequence, sessile organisms can react to environmental stimuli from every direction. On the other hand, bilateral symmetry allows motile organisms the arrangement of a specialized nervous system from the anterior end of the organism (i.e., the 'head'). Moreover, another important advantage of bilateral symmetry is the ability to equalize environmental pressures on both sides of the body, thereby enabling a rectilinear motion.
Answer:
The presence of an additional chromosome
Explanation:
Look at "pair" 21. See how there are THREE chromosomes instead of TWO? Normally, there would only be two chromosomes in each pair but this karyotype shows a trisomy (see def. below) of the 21st pair. This was caused by a nondisjunction mutation of the 21st pair. The is also the karyotype of a person with Down's Syndrome.
Definition of Trisomy:
A condition of the presence of three chromosomes in a pair instead of two. This normally causes developmental irregularity.
