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Chapter 2.1 Check and Reflect
Page 63 # 1-5, 7, 10, 11, 15
1. An organ is a group of tissues that is organized and works together to perform a specific
function. Examples of animal organs include the skin, lung, heart, and stomach. Examples of
plant organs include the leaf, roots, stem, and flower.
2. (a) The epidermis is the outer layer of skin and provides protection.
(b) The dermis is the inner layer of skin and contains different types of tissues. Connective
tissue provides support and structure. Fat tissue is also connective tissue and is at the base of the
dermis to provide insulation. Blood vessels are a type of connective tissue that can dilate to allow
excess heat to be released. Nerve tissue senses pain, heat, and pressure, and sends this
information to the brain. Muscle tissue in the dermis produces goosebumps.
3. (a) Lungs contain connective tissue and epithelial tissue.
(b) The connective tissue provides structure. Blood is used to transport oxygen from the lungs
throughout the body and take carbon dioxide from the body to be released into the lungs to be
exhaled. Lungs are also made from other connective and epithelial tissues. The epithelial tissue
makes up the thin walled alveoli that line the lungs.
4. (a) The heart is a pump that supplies blood to all parts of the body.
(b) The right side of the heart pumps blood to the lungs so that the blood can pick up oxygen.
The blood then is pumped back to the left side of the heart, which pumps the oxygenated blood
to the rest of the body.
5. The stomach is designed to churn (squish and mix) food and blend it with digestive juices and
enzymes. In the intestines, nutrients are absorbed into the body, and waste is removed.
7. The function of a flower is to produce seeds to reproduce the plant.
10. Three organs in which you would expect to find muscle tissue would be the stomach, the
intestines, and the heart.
11. During the winter months, there is a reduced amount of sunlight. The ultraviolet light from
sunlight is absorbed by the epidermis and is used to make vitamin D, which is needed for bone
development. When there is reduced sunlight, not enough vitamin D is made naturally in the
epidermis.
15. The steps involved in gas exchange in a leaf are as follows: first, the water is carried up from
the roots through the vascular tissues, through the stem to the leaves. Carbon dioxide enters
through the stomate (an opening in the epidermal tissue) in the leaf. In the
mesophyll tissue of the leaf, photosynthesis takes place, using sunlight, carbon dioxide, and
water, to produce oxygen and sugar. The oxygen and excess water exit the leaf through the
stomate.
Chapter 2.2 Check and Reflect
Page 77 #1-9, 12
1. An organ system consists of organs that work together to accomplish tasks. Student examples
of organ systems may vary but could include integumentary, skeletal, circulatory, respiratory,
and digestive systems.
2. The circulatory system transports materials throughout the body.
3. The organs involved in the digestive system are:
• mouth: food enters and is ground up by teeth, while enzymes from saliva begin
chemically breaking down the food
• esophagus: transports food to the stomach
• stomach: physically and chemically breaks down food
• intestines: enzymes continue food breakdown, and walls absorb nutrients
• pancreas: produces hormones to control metabolism and produces pancreatic juices,
which contain digestive enzymes to help break down carbohydrates, proteins, and fats
• gall bladder: stores bile, which is used to help break down fats
• liver: produces chemicals, such as bile, for digestion
• rectum and anus: stores wastes until they elimination occurs
4. The respiratory system is involved in breathing.
5. The muscle tissue in the digestive system of the earthworm pushes the food from the mouth,
through the esophagus to the crop.
6. Accessory structures to the integumentary system include horns, antlers, hooves, quills, claws,
hair, and nails. These structures protect the body from temperature (hair) and from predators
(horns, claws, and nails), and they provide support (hooves).
7. TABLE 2.1 Organs and Their Job Descriptions
Organ
Job Description
heart
• pumps blood
teeth
• grind food
intestines
• break down food and absorb nutrients
skin
• covers and protects surface
kidney
• filters and cleans blood
esophagus
• passes food from the mouth to the stomach
bladder
• stores urine
brain
• controls whole body
lungs
• exchange gases
8. The two organ systems in plants are the shoot and root systems.
9. The crop and gizzard are important parts in the earthworm’s digestive system because the crop
stores dirt until it can be digested, and the gizzard grinds up the food.
12. Students’ answers may vary but could include:
• when you breathe in, the diaphragm contracts and moves downward, and the chest muscles cause
the rib cage to rise. This increases the size of the chest cavity, which causes a decrease in air
pressure. Since the air pressure is less than the air pressure outside, air rushes into the lungs
• when you breathe out, the diaphragm relaxes and moves upward, and the chest muscles cause the
rib cage to fall. This decreases the size of the chest cavity, which causes an increase in air pressure.
Since the air pressure is greater than the air pressure outside, air rushes out of the lungs
Chapter 2.3 Check and Reflect
Page 86 # 1, 2, 4, 6, 8, 9
1. Homeostasis means steady state.
2. The respiratory system, the digestive system, and the circulatory system interact together to
supply cells with needed nutrients. The respiratory system provides oxygen. The digestive
system provides nutrients. The circulatory system transports the nutrients and oxygen around the
body.
4. (a) The average range for the pulse rate of a teenager is 60–80 beats per minute.
(b) The pulse rate indicates how often the heart beats per minute.
6. A doctor uses the results of a blood test to determine the blood levels of hormones produced
by the thyroid. The hormone levels indicate how the thyroid is functioning.
8. The systolic and diastolic pressures indicate how well the circulatory system is working. The
systolic pressure indicates the pressure when the heart is pushing blood. The diastolic pressure
indicates the pressure when the heart is resting and filling with blood. For example, a blood
pressure of 135/85 mm Hg indicates there is too much pressure in the arteries.
9. Sweat is made of water and waste salts. When the sweat on the surface of the skin evaporates,
it cools the body.
3.1 Check and Reflect
Page 101 # 1, 2, 5, 7, 10, 12, 14, 15
1. Limitations of the use of X-rays include the damage to DNA caused by the radiation, and the
tendency of X-rays to penetrate soft tissues, which cannot be seen on an X-ray.
2. Students’ answers may vary.
• X-rays are used to image bones for breaks, to look at teeth for cavities, to see abnormalities in some
organs, and to check the structure of blood vessels.
• Fluoroscopy uses X-rays to produce images showing movement of organs. Patients may have to
drink a contrast liquid, such as barium or iodine, to help see the organ.
• Ultrasound uses high-frequency sound waves to produce images of tissues and organs. It is also
used in pregnancy to check the health and development of the fetus.
• Computed tomography (CT) uses X-rays to create a 3-D image from a series of images taken at
different angles. It is used to diagnose cancer and vascular disease, and to look for abnormalities in
the skeletal system.
• Magnetic resonance imaging (MRI) uses powerful magnets and radio waves to produce detailed
images of the body. It is used to image the brain, heart, liver, soft tissues, and the interior of bones. It
can also be used to diagnose cancer, brain diseases, and cardiovascular conditions.
• Nuclear medicine uses radioactive isotopes to provide images of how tissues and organs function.
• Positron emission tomography (PET) is a type of nuclear medicine that is used to detect cancer in
tissues or to examine the effects of cancer treatments. It can also be used to detect some brain
disorders.
• Biophotonics uses interactions of light with cells and tissues to look for and to treat abnormalities in
organs. For example, a thin tube light and camera can be used to look at the stomach and intestines.
5. A radiologist is a doctor who has been trained to read and interpret radiographs to diagnose disease
or problems.
7. Ultrasound is not an appropriate choice for imaging the bowel because the images can be blurred
by air or other gases.
10. Biophotonics is used to examine the digestive tract through a gastrointestinal endoscopy or a
colonoscopy. It is also used to remove gallbladders and repair knees.
12. Students’ answers may vary. Since the doctor suggests there is a problem in the circulatory
system, the following medical imaging tests would be appropriate:
• X-rays to provide a chest radiograph to see the size of the heart and associated blood vessels
• fluoroscopy to study the blood vessels of the heart and a coronary angiogram to show the flow of
blood through arteries
• echocardiogram (type of ultrasound) to look for abnormalities in the heart or blood vessels
• CT scan of blood vessels as well as the skeleton and soft tissue to produce a three-dimensional
image
• MRI to diagnose certain cardiovascular conditions
• PET scan to look for heart disease
14. Bones appear white on a radiograph because they absorb X-rays.
15. Since X-rays can damage cell DNA, parts of the body that are not being imaged are covered by a
protective lead apron.
Chapter 2.3 Check and Reflect
Page 111 # 2-4, 9
2. The most commonly administered vaccine in Ontario is the influenza vaccine.
3. The MMR vaccine protects against measles, mumps, and rubella. These diseases are infectious
viruses that can cause complications, such as mental retardation, sterility, and deafness. The HPV
vaccine protects against cervical cancer caused by the human papillomavirus.
4. HIV is the human immunodeficiency virus. HIV causes the human immune system to become
weak, which leaves an individual susceptible to a variety of infections. Acquired immunodeficiency
syndrome (AIDS) is the advanced stage of HIV infection.
9. (a) DNA screening involves testing an individual’s DNA for a series of genes that are
related to such diseases as heart disease and certain types of cancers.
(b) In the future, DNA screening may become part of the diagnosis and treatment of
diseases. For example, if a person has specific genes showing a higher risk for certain
diseases or cancers, preventative treatments may be possible.