4. Sobre la excreción; Responde verdadero o falso: A. Mediante este proceso eliminamos productos de desecho resultantes de la actividad celular. F V
B. Sólo realizan excreción los riñones F V
C. Los pulmones realizan excreción ya que eliminan CO2 F V
D. Mediante el sudor eliminamos productos de desecho. F V
E. En la formación de la orina no intervienen las substancias presentes en la sangre F V
F. La orina se forma a partir de la sangre por filtración en el glomérulo. F V
G. La orina se almacena en la vejiga F V
H. Los uréteres conducen la orina desde los riñones a la uretra F V

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

What makes a dominant allele different from a recessive allele

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.