Answer:
Your heart changes its rate depending on the activity, so that it can carry blood to your muscles, and therefore it needs to beat stronger if you are performing some exercise, or not so strong if you are sleeping, for example.
Explanation:
Your heart is continuously beating to keep blood circulating throughout your body.
So, here it is why your heart changes its rate: Its rate changes depending on your activity level; it is lower while you are asleep and at rest and higher while you exercise to supply your muscles with enough freshly oxygenated blood to keep the functioning at a high level.
And how: depending on your activity level, your heart has to pump enough blood to your muscles. Blood carries needed oxygen and other nutrients. Muscles need more blood sugar than any other tissue especially when working hard. To supply your muscles with oxygen your heart needs to beat faster, and this builds up your heart muscles.
Cells need a source of energy, they get this energy by breaking down food molecules to release, the stored chemical energy.
Answer:
A differential medium
Explanation:
Bacteria require nutrients for growth, and in order to culture (grow) them and study their characteristics, different types of media are used.
A selective media is used to grow a particular group of organism while suppressing another. So a selective media usually has an inhibitory agent, which will inhibit the growth of the undesired group. An antibiotic can be added to a medium to make it selective.
A general purpose medium as the name implies can be used to grow any group of bacteria. It has no inhibitory agent and indicator that differentiates between organisms. An example of general purpose media is nutrient agar
.
A non-synthetic media is made from natural ingredients.
A differential media differentiates between groups of organisms. Example of differential media is MacConkey agar and Mannitol Salt agar. On MacConkey agar, lactose fermenting bacteria turn pink while non-lactose fermenting bacteria are colorless.
On Mannitol Salt agar, mannitol fermenting bacteria turn yellow while non-mannitol fermenting bacteria are colorless. Mannitol Salt agar is also a selective medium. It has a high salt concentration which inhibits certain organisms.
Answer:
C. Meiosis since it produces haploid cellsneeded for reproduction.
C hope this helps. ............
