Human Body MSL Practice Question Answers
A) Summarize the hierarchical organization of multi-cellular organisms.
Cells work together to form tissues – tissues work together to form organs – organs work together to
form organ systems – organ systems work together to make an organism
B) There are many body systems which carry out important functions.
 Summarize the functions of the digestive system.
The digestive system has three main functions in the human body. It breaks down food into
molecules the body can use. These molecules are absorbed into the blood and carried
throughout the body. The digestive system will also eliminate solid waste from the body.
 Summarize the functions of the respiratory system.
The respiratory system has three main jobs in the human body. It will bring air into the body
and transport it to the lungs. In the alveoli, gas exchange will occur and the oxygen from the air
will move into the blood stream. The waste products will move from the blood stream and into
the alveoli. When you exhale, these waste products are removed from the body
 Summarize the functions of the reproductive system.
The function of the reproductive system is to ensure survival of the species. It produces sex
cells (egg or sperm) and it will transport the cells when necessary. The female reproductive
system also nurtures the developing offspring. Both male and female reproductive systems
produce hormones that help to maintain homeostasis.
 Summarize the functions of the circulatory system.
The circulatory system is the transportation system of the body. It carries needed substances
to cells and carries waste products away from cells. In addition, blood contains cells that fight
disease.
 Summarize the functions of the excretory system.
The excretory system removes excess water, urea, carbon dioxide, and other wastes from our
blood.
C) There are many organs or parts of the body associated with specific body systems.
 Construct an organ or part of the body that is associated with the digestive, respiratory,
reproductive, circulatory and excretory systems.
 Explain how each organ works within the system it is associated with.
a) Digestive – The stomach is a J-shaped pouch that is used to
chemically and mechanically break down food into their nutrients.
b) Respiratory – The lungs are where the alveoli
exchanged happens. They give oxygen to the
products from the blood.
are located and the place where gas
blood and take away the waste
c) Reproductive – The uterus is the part of
the female reproductive system where the
fetus is nurtured until birth.
d) Circulatory – The heart is the
pump of the circulatory system
and helps to circulate and
deliver needed nutrients
throughout the body.
e) Excretory – The kidneys filter blood and removed
waste products. These waste products are then
removed from the body.
D) Explain the process of homeostasis.
Homeostasis is the process of the body keeping a constant internal environment despite changes in the
outside environment.
E) Identify two ways homeostasis is maintained within the body.
1. The body will adjust to keep the temperature constant by shivering when you are too cold and
sweating when you are too hot.
2. The heart rate and breathing rate speed up and slows down depending on the oxygen needs of the
body
F) Explain how the above 5 body systems work together to help the body function properly.
The respiratory system helps to bring oxygen into the body. It works very closely with the circulatory
system to carry the oxygen throughout the body to all the cells. It will also transport waste products to
the respiratory system for gas exchange where the lungs exhale the waste out of the body. The
circulatory system also carries nutrients to the cells in the body after they have been digested and
absorbed in the digestive system. The excretory system works with the circulatory system to help filter
out waste products from the blood. The kidney does this and then it is removed from the body as
liquid waste. The reproductive system produces hormones that are carried throughout the body by
the blood. These hormones help to regulate growth and development as well as maintain
homeostasis.
G) Explain how environmental issues can affect the human body.
1. Air pollution can make it hard for a person to breathe while they are outdoors. This type of
pollution can also lead to the development of asthma in some humans.
2. Excessive heat can lead to dehydration of the body if you do not consume enough water to replace
what has been lost due to sweating.
3. Water pollution is when water becomes contaminated due to toxins being dumped into the ground
or nearby water systems. These toxins can cause a person to become ill if they ingest the water or
break out in a rash, if the water comes in contact with their skin.
H) Describe three ways you can help keep your body healthy.
1. Exercise regularly – at least 30 minutes a day
2. Eat a healthy balanced diet
3. Get the recommended amount of sleep for a person your age