B becuase wait for the first one day and then i’m the park to go go ahead to get it out and i’m and then i’m and i will
Typically you use experimental and control groups in an experiment. a control group is like the default, and the experimental is the one you actually experiment with.
for example if i run an experiment on the effects of food dye on a leaf stem, i’ll have my control group (the ones without food dye) to compare to the experimental group (the ones with food dye)
the control group is a way for scientists to see how an experiment truly affected or altered the subject
Answer: Option B) . a decrease in the amount of oxygen dissolved in
the pond
Explanation:
Anaerobic bacteria are able to survive in the absence of oxygen while aerobic bacteria survive only in the presence of abundant oxygen.
Hence, while reduced levels of dissolved oxygen in the pond decrease the amount of aerobic bacteria like Bacillus; anaerobic bacteria like Actinomyces flourish since they survive on organic substances like methane, cellulose instead.
The gaps (approximately 1 micrometer wide) formed between myelin sheath cells long the axons are called Nodes of Ranvier. Since fat serves as a good insulator, the myelin sheaths speed the rate of transmission of an electrical impulse along the axon.
During inhalation, you breathe in and this contracts the diaphragm and moves downwards. This increments the chest cavity space which means the lungs are expanding. The intercostal muscles or the muscles in between the ribs also aids in the enlargement of the chest cavity. Both muscles contract to pull your rib cage upward and outward when you inhale. As your lungs expand, air is sucked through your nose and mouth. It then travels down to the windpipe and into the lungs to the bronchus, bronchioles and eventually in the alveoli where air exchange between carbon dioxide and oxygen happens.
The additional accessory muscles of respiration are typically used only under conditions that are of high metabolic demand or respiratory dysfunction. However, in instances where these muscles become stiff and hard, expansion of the rib cage can be quite restricted. The accessory muscles of respiration include sternocleidomastoid and the scalene muscles namely anterior, middle and posterior scalene. Both aid in elevating the rib cage. However, their involvement seems to depend on the degree of respiratory effort. During quiet breathing, the scalenes are consistently active at certain phases while the sternocleidomastoid is quite.
