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.
1) Speed = distance / time
s = 60 / 2
s = 30 km/h
In short, Your Answer would be Option B
2) Speed = distance / time
s = 25/4
s = 6.25 km/h
In short, Your Answer would be Option B
[ Direction not needed as it is speed not velocity ]
Hope this helps!
Carbohydrates are naturally occurring sugars, starches and fiber in food. All carbohydrates are made up of sugar molecules. Sugar molecules linked together form starches and fiber. In the body, starches and sugars are broken down in the digestive system to glucose.
Answer:
Respiratory system and circulatory system.
The respiratory system allow living things to obtain oxygen from the air while the circulatory system allows oxygen to be carried around the body.
Answer:
When replication mistakes are not corrected, they may result in mutations, which sometimes can have serious consequences. Point mutations, one base substituted for another, can be silent (no effect) or may have effects ranging from mild to severe.
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