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If a portion of a strand of DNA bases reads 3’TCGATCGCA 5’, what would the sequence of bases on the complementary strand read?

A. 5’AGCTAGCGT 3’

B. 3’ TCGUTCGCU 5’

C. 3’ AGCTAGCGT 5’

D. 5’ GGUTACTAC 3’

Answer Explanation:

The sequence of bases on the complementary strand of DNA would read 5’AGCTAGCGT 3’ (Choice A). In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The complementary strand is also antiparallel to the original strand, meaning that it runs in the opposite direction with the 5' end matching up with the 3' end of the original strand.

The other options do not accurately represent the complementary sequence of bases or the antiparallel orientation of the strands.

BONUS:
 

Therefore, the Correct Answer is A.

More Questions on TEAS 7 Science

  • Q #1: Which of the following functions does the myelin sheath perform for a nerve cell?

    A. Insulation

    B. Regeneration

    C. Sensory perception

    D. Nutrition

    Answer Explanation

    The myelin sheath is a protective membrane that wraps around parts of certain nerve cells.

    Its fatty-protein coating provides protective insulation for your nerve cell like the plastic insulation covering that encases the wires of an electrical cord ².

    This allows the electrical impulses to travel quickly and efficiently between one nerve cell and the next. The other options are incorrect because they do not describe the functions of the myelin sheath.

    Regeneration, sensory perception, and nutrition are not functions performed by the myelin sheath for a nerve cell.

  • Q #2: Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

    A. Oxygen

    B. Carbon monoxide

    C. Carbon dioxide

    D. Carbonic acid

    Answer Explanation

    The correct answer is d. Carbonic acid. When blood pH rises, carbonic acid can donate H+ ions to act as a buffer and help maintain the pH within a normal range. Carbonic acid is formed when carbon dioxide dissolves in water and reacts with it.

    A. Oxygen is not responsible for donating H+ ions to act as a buffer when blood pH rises.

    B. Carbon monoxide is a toxic gas that does not play a role in buffering blood pH.

    C. Carbon dioxide can dissolve in water to form carbonic acid, which can then donate H+ ions to act as a buffer.

  • Q #3: Which of the following is a function of bone?

    A. Storage of minerals

    B. Detoxification of alcohol

    C. Secretion of hormones

    D. Production of otoliths

    Answer Explanation

    The correct answer is a. Storage of minerals. Bones serve as a storage site for minerals such as calcium and phosphorus. These minerals are essential for various bodily functions and can be released from the bones into the bloodstream when needed.

    b. Detoxification of alcohol is not a function of bone. This process occurs primarily in the liver.

    c. Secretion of hormones is not a function of bone. Hormones are produced and secreted by glands such as the pituitary gland, thyroid gland, and adrenal glands.

    d. Production of otoliths is not a function of bone. Otoliths are small calcium carbonate structures found in the inner ear of fish and other vertebrates that help with balance and hearing.

  • Q #4: Genetic information describing the characteristics of an organism is found in which of the following?

    A. Nuclei

    B. Membranes

    C. Cilia

    D. Ribosomes

    Answer Explanation

    The correct answer is a. Nuclei. Genetic information describing the characteristics of an organism is found in the nuclei of its cells. The nucleus contains the organism's DNA, which carries the genetic information that determines its traits.

    b. Membranes are structures that surround and enclose cells and organelles, but they do not contain genetic information.

    c. Cilia are hair-like structures that protrude from the surface of some cells and are involved in movement, but they do not contain genetic information.

    d. Ribosomes are organelles that are involved in protein synthesis, but they do not contain genetic information.

  • Q #5: Parasitic worm infestation is hypothesized to be damaging to the host. However, scientists have recently discovered that worm infestation can relieve the effects of certain autoimmune disorders. In which of the following ways should the hypothesis be modified, given the new findings?

    A. Worm infestation prevents the body from immune malfunction.

    B. Worm infestation reduces the severity of certain autoimmune disorders.

    C. Lack of worm infestations is the cause of some autoimmune disorders.

    D. Worm infestations exacerbate the body's immune reaction.

    Answer Explanation

    Given the new findings that worm infestation can relieve the effects of certain autoimmune disorders, the hypothesis should be modified to state that worm infestation reduces the severity of certain autoimmune disorders.

    This option best reflects the new information and suggests a potential benefit of worm infestation in relation to autoimmune disorders. The other options do not accurately reflect the new findings and do not provide a clear modification to the hypothesis.

  • Q #6: An individual suffers severe blunt trauma to the thoracic cavity. Which of the following organs are at greatest risk from this injury?

    A. Heart and lungs

    B. Brain and spinal cord

    C. Liver and stomach

    D. Large and small intestines

    Answer Explanation

    The correct answer is a. Heart and lungs. The thoracic cavity contains the heart and lungs, which are at greatest risk from severe blunt trauma to this area.

    a.The brain and spinal cord are not located in the thoracic cavity and are therefore not at greatest risk from blunt trauma to this area.

    c.The liver and stomach are located in the abdominal cavity, which is below the thoracic cavity. While these organs may be affected by severe blunt trauma to the thoracic cavity, they are not at greatest risk.

    d.The large and small intestines are also located in the abdominal cavity and are not at greatest risk from blunt trauma to the thoracic cavity.

     

  • Q #7: Which of the following structures is an exocrine gland?

    A. Pineal gland

    B. Parathyroid gland

    C. Parotid gland

    D. Pituitary gland

    Answer Explanation

    The parotid gland is an exocrine gland that secretes saliva into the mouth. Exocrine glands secrete their products into ducts that carry the secretions to the body's surface or into body cavities. The other options are endocrine glands, which secrete hormones directly into the bloodstream. The pineal gland secretes melatonin, the parathyroid glands secrete parathyroid hormone, and the pituitary gland secretes several hormones that regulate various bodily functions.

  • Q #8: If a mother's____________ cell contains mutated DNA, this mutation can be passed to her offspring. Which of the following options correctly completes the sentence above?

    A. somatic

    B. white blood

    C. germ.

    D. Stem

    Answer Explanation

    The correct answer is c. germ. If a mother's germ cell contains mutated DNA, this mutation can be passed to her offspring. Germ cells are the reproductive cells (eggs in females and sperm in males) that carry genetic information from one generation to the next.

    a. Somatic cells are all the other cells in the body that are not germ cells. Mutations in somatic cells are not passed on to offspring.

    b.White blood cells are a type of somatic cell that plays a role in the immune system.

    d. Stem cells are undifferentiated cells that have the ability to develop into different types of cells in the

    body.

  • Q #9: Which of the following growth curves shows a population that is at its carrying capacity?

    A. B

    B. C

    C. A

    D. D

    Answer Explanation

    A population is said to be at its carrying capacity when it has reached the maximum number of individuals that can be sustained in a particular environment over a prolonged period of time, given the available resources and the prevailing environmental conditions.

    In other words, carrying capacity refers to the maximum population size that a given ecosystem can support without being depleted of resources or experiencing environmental degradation. Once a population reaches its carrying capacity, its growth rate slows down and stabilizes, as individuals start to compete more intensely for resources such as food, water, and shelter, and mortality rates increase.

    Carrying capacity is an important concept in ecology and population biology because it helps to explain the dynamics of natural populations and how they are influenced by changes in the environment, such as climate change, habitat loss, and human activities.

  • Q #10: Which of the following substances is excreted by sweat glands in response to the breakdown of proteins and the formation of ammonia?

    A. Lysozymes

    B. Urea

    C. Water

    D. Sebum

    Answer Explanation

    Urea is a waste product that is formed when proteins are broken down in the body. It is excreted by the kidneys in urine, but small amounts can also be excreted by sweat glands in sweat.

    The other options are not substances that are excreted by sweat glands in response to the breakdown of proteins and the formation of ammonia. Lysozymes are enzymes that break down bacterial cell walls, water is a component of sweat but is not specifically related to protein breakdown, and sebum is an oily substance produced by sebaceous glands to lubricate the skin.