Which of the following statements is true regarding vaccines?
A. Vaccines can cause the disease they are designed to protect against
B. Vaccines work by providing passive immunity to the individual
C. Vaccines work by exposing the individual to a weakened or inactivated form of the pathogen
D. Vaccines only provide protection against bacterial infections
Vaccines are a type of preventative medicine that work by exposing the individual to a weakened or inactivated form of a pathogen (such as a virus or bacteria) or to a piece of the pathogen (such as a protein or sugar) that triggers an immune response in the body. This exposure allows the body to develop immunity to the pathogen without getting sick from the full-blown disease. Once the immune system has been primed, it can recognize and quickly respond to the pathogen if it is encountered again in the future, providing protection against the disease.
It is a common misconception that vaccines can cause the disease they are designed to protect against. This is not true. While some vaccines may cause mild symptoms such as a low-grade fever or soreness at the injection site, they do not cause the full-blown disease.
Vaccines provide active immunity, meaning that the body produces its own antibodies against the pathogen, rather than receiving pre-made antibodies as in passive immunity. Additionally, vaccines can be effective against both bacterial and viral infections, depending on the specific vaccine.
Therefore, the Correct Answer is C.
More Questions on TEAS 7 Science
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Q #1: What are the five regions of the vertebral column, starting from the top and moving downwards?
A. Cervical, thoracic, lumbar, sacral, coccygeal
B. Thoracic, cervical, lumbar, sacral, coccygeal
C. Lumbar, thoracic, cervical, coccygeal, sacral
D. Sacral, lumbar, cervical, thoracic, coccygeal
Answer Explanation
The vertebral column, also known as the spine or spinal column, is a series of bones called vertebrae that extend from the skull to the pelvis. It provides support for the body and protects the spinal cord. The five regions of the vertebral column, starting from the top and moving downwards, are:
- Cervical: This region is made up of seven vertebrae and is located in the neck. The first two cervical vertebrae, the atlas and the axis, are specialized to allow for head movement.
- Thoracic: This region is made up of twelve vertebrae and is located in the upper and middle back. The thoracic vertebrae are larger than the cervical vertebrae and articulate with the ribs.
- Lumbar: This region is made up of five vertebrae and is located in the lower back. The lumbar vertebrae are the largest and strongest of the vertebrae.
- Sacral: This region is made up of five fused vertebrae and is located in the pelvis. The sacrum forms the posterior wall of the pelvis and articulates with the hip bones.
- Coccygeal: This region is made up of four fused vertebrae and is located at the base of the vertebral column. The coccyx, or tailbone, provides atachment points for muscles and ligaments.
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Q #2: During embryonic development, which of the following germ layers forms the nervous system?
A. Ectoderm
B. Endoderm
C. Mesoderm
D. Exoderm
Answer Explanation
The three germ layers that form during embryonic development are the ectoderm, mesoderm, and endoderm. The ectoderm is the outermost layer, and it gives rise to the skin, hair, nails, and nervous system. The nervous system develops from a specialized region of the ectoderm called the neural plate, which invaginates to form the neural tube. The neural tube ultimately gives rise to the brain and spinal cord, which make up the central nervous system, as well as the peripheral nervous system. The endoderm gives rise to the lining of the digestive and respiratory tracts, while the mesoderm gives rise to the musculoskeletal system, circulatory system, and several other organs. The exoderm is not a germ layer and does not exist during embryonic development.
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Q #3: Which of the following describes the process of osmosis?
A. Movement of substances from an area of high concentration to an area of low concentration.
B. Movement of substances against a concentration gradient with the help of transport proteins.
C. Movement of water molecules from an area of high concentration to an area of low concentration through a selectively permeable membrane.
D. Movement of substances into a cell by engulfing them with the plasma membrane.
Answer Explanation
Osmosis is the process by which water molecules move across a selectively permeable membrane from an area of high concentration to an area of low concentration, in order to equalize the concentration of solutes on both sides of the membrane. Selectively permeable membranes allow only certain molecules to pass through, while preventing the passage of others.
In osmosis, the movement of water molecules is driven by the concentration gradient of solutes, which cannot pass through the membrane. If one side of the membrane has a higher concentration of solutes than the other, water molecules will move from the side with the lower concentration of solutes to the side with the higher concentration of solutes, in an atempt to dilute the solutes and equalize the concentration on both sides.
Osmosis is important in many biological processes, including the uptake of water by plant roots, the regulation of water balance in animal cells, and the preservation of food by adding salt or sugar to create a hypertonic environment that inhibits bacterial growth.
