Answer:
In the animals control and co-ordination is done by the nervous system and endocrine system whereas in animals nervous system is adequately developed and consists of brain, spinal cord and nerves; in animals hormones are secreted by endocrine glands.
Explanation:
Answer:
a. Manipulated variable: TEMPERATURE
b. Responding variable: CRICKET CHIRP
c. Controlled variable: Same species of cricket
d. Hypothesis: IF the temperature is increased, THEN crickets will chirp more
Explanation:
Independent variable, also called the manipulated variable, is the variable that is changed or manipulated in an experiment. In this case, the independent variable is the TEMPERATURE.
Dependent or responding variable is the variable that responds to changes made to the independent variable. The dependent variable in this case is CHIRP OF THE CRICKETS.
Controlled variable is the variable that must be kept unchanged for all groups throughout the experiment. The controlled variable in this case is SAME SPECIES CRICKET USED.
Hypothesis is a testable explanation (via experimentation) to an observed problem or a given question. In this investigation involving Melissa, an hypothesis is: IF the temperature is increased, THEN crickets will chirp more.
A scientific question is one which can be tested using a set of experiments and comparing with a control variable. Out of the given questions, the nonscientific questions are:
"Why do people in my neighborhood have more cats than dogs?"
"How can the position of the stars and planets be used to predict the future?"
Both of these questions can not be answered through the scientific method, so they are nonscientific.
Answer:
The correct answer is - the presence of pores.
Explanation:
The name Porifera is a term that means pore bearer as these individuals are one cell thick with many tiny pores present on their body and some big openings as well. These small pores are one of the characteristic features of these organisms. It distinguished the Porifera phylum from the Cnidaria phylum. There are many other microscopic and behavioral features present to classify them but in the lab presence of pores is important.
Answer:
B. A drug that prevents the conversion of glucose into pyruvate
Explanation:
<em>Streptococcus mutans</em> is a facultatively anaerobic bacterium, i.e., a microorganism capable of producing ATP by both aerobic (when there is oxygen), and anaerobic (i.e., when there is no oxygen available) conditions. This bacterium is observed in the human oral cavity where causes the majority of tooth decay. <em>S. mutans</em> can digest carbohydrates (e.g. glucose, fructose and lactose) in order to produce lactic acid, which contributes to tooth decay. Glycolysis is the fermentation of glucose to pyruvate in anaerobic conditions, and thereby it is expected that a drug capable of preventing the conversion of glucose into pyruvate in anaerobic conditions is effective to prevent cavities caused by <em>S. mutans</em>.
