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Which of the following is a mass within the ovary that secretes hormones to maintain the uterine lining during pregnancy?

A. Oviduct

B. Corpus luteum

C. Oocyte

D. Umbilical cord

Answer Explanation:

Corpus luteum. The corpus luteum is a temporary structure that forms from the ruptured follicle after ovulation. It produces progesterone, which is a hormone that prepares the endometrium (the inner lining of the uterus) for implantation of a fertilized egg. If pregnancy occurs, the corpus luteum continues to secrete progesterone until the placenta takes over. 

Corpus Luteum (Cleveland Clinic) 

Therefore, the Correct Answer is B.

More Questions on TEAS 7 Science

  • Q #1: Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

    A. Carbon dioxide

    B. Carbonic acid

    C. Oxygen

    D. Carbon monoxide

    Answer Explanation

    A buffer is a solution that can resist changes in pH when small amounts of acid or base are added. In the human body, blood is an important buffer that helps maintain a stable pH of about 7.4. One of the main components of the blood buffer system is the bicarbonate buffer, which involves the equilibrium between carbon dioxide (CO2), carbonic acid (H2CO3), and bicarbonate ions (HCO3-). When blood pH rises, meaning it becomes more basic, the bicarbonate buffer can donate H+ ions to lower the pH and restore the balance. The substance that donates H+ ions in this case is carbonic acid, which dissociates into H+ and HCO3-. Therefore, 

     

  • Q #2: To separate genomic DNA fragments by size, which of these laboratory methods is most useful?

    A. Filtration

    B. Spectrophotometry

    C. Titration

    D. Electrophoresis

    Answer Explanation

    One of the most common techniques for separating DNA fragments by size is electrophoresis. Electrophoresis is a process that uses an electric field to move charged molecules through a porous gel matrix. The gel acts as a sieve, allowing smaller molecules to move faster and farther than larger ones. By applying a dye to the DNA samples and loading them into wells at one end of the gel, the DNA fragments can be visualized as bands after electrophoresis. The distance of each band from the well indicates the size of the corresponding DNA fragment.

  • Q #3: Which of the following allows the AIDS virus, which contains RNA, to insert viral DNA into the DNA of a host T-cell after the AIDS virus enters the cell?

    A. Reverse transcriptase, an enzyme encoded by the virus.

    B. Receptor proteins located on the surface of the virus.

    C. The phospholipids found on the envelope of the virus.

    D. The protein that makes up the capsid of the virus.

    Answer Explanation

    Reverse transcriptase, an enzyme encoded by the virus. This enzyme can convert the viral RNA into DNA, which can then integrate into the host cell's genome and hijack its machinery to produce more viruses. The other options are not relevant to this process. Receptor proteins are involved in binding the virus to the cell membrane, but they do not insert viral DNA into the cell. The phospholipids and the protein capsid are structural components of the virus, but they do not have any enzymatic activity.