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Which of the following is a component of a chromosome?

A. Centromere

B. Gamete

C. Homologue

D. Ribose

Answer Explanation:

The protein disc that holds two sister chromatids together is what collectively makes a chromosome. A gene is a segment of DNA, deoxyribonucleic acid, which transmits information from parent to offspring. A single molecule of DNA has thousands of genes. A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division.

Chromosomes have two components:

  • Chromatids: two copies of each chromosome
  • Centromeres: protein discs that attach the chromatids together

Human cells have 23 sets of different chromosomes. The two copies of each chromosome are called homologous chromosomes, or homologues. An offspring receives one homologue from each parent. When a cell contains two homologues of each chromosome, it is termed diploid (2n). A haploid (n) cell contains only one homologue of each chromosome. The only haploid cells humans have are the sperm and eggs cells known as gametes.

Therefore, the Correct Answer is A.

More Questions on TEAS 7 Science

  • Q #1: As soon as an invader, known as a(n) _____, enters the body, the body begins to fight.

    A. antibody

    B. pathogen

    C. trigger

    D. vaccination

    Answer Explanation

    Pathogen is an infectious foreign body that enters the body and causes disease or illness to the person. There are five types of pathogens: viruses, bacteria, fungi, protozoa, and worms. Pathogens have antigen proteins found on their surface and are unique to each pathogen.

    Antibody is a protein produced by the body’s immune system when it detects harmful substances (antigens). There are many different antibodies found in the body. Each one is unique and protects the body against the specific antigen that it detects at any given time. If there are no antibodies for a specific antigen, the more likely you are to develop an illness.

    Vaccinations are the introduction of a dead or disabled pathogen or of a harmless microbe with the protein of a pathogen on its surface into the body. Often administered through needle injection, to stimulate the immune system to produce immunity to a specific disease Immunity protects the body from a disease when exposed to it.

    There are four types of immunity: natural/passive, natural/active, artificial/passive, and artificial/ active.

    • Natural/passive – Babies receive immunities from breastmilk.
    • Natural/active – The body produces antibodies to combat an illness when a person becomes sick.
    • Artificial/passive – This immunity is temporary and requires doses of serum to maintain the immunity.
    • Artificial/active – A vaccination provides artificial/active immunity.

  • Q #2: While hiking, a person is startled after encountering a bear. Her palms get sweaty and her heart starts racing. Which part of her nervous system was directly stimulated?

    A. Central

    B. Parasympathetic

    C. Somatic

    D. Sympathetic

    Answer Explanation

    The autonomic nervous system is responsible for activities that are nonvoluntary and under unconscious control. This system controls glands and the smooth muscles of internal organs, heart rate, breathing, and digestion. The autonomic nervous system is further divided into the following:

    • Sympathetic nervous system: The sympathetic nervous system focuses on emergency situations by preparing the body for fight or flight. (Sympathetic = Stress)
    • Parasympathetic nervous system: The parasympathetic nervous system controls involuntary processes unrelated to emergencies. This system deals with “rest or digest” activities. (Parasympathetic = Peace)

    The somatic nervous system primarily controls voluntary activities such as walking and riding a bicycle. Thus, this system sends information to the CNS and motor nerve fibers that are attached to skeletal muscle.

  • Q #3: A spoonful of sugar is added to a hot cup of tea. All the sugar dissolves. How can the resulting solution be described?

    A. Saturated and homogeneous

    B. Saturated and heterogeneous

    C. Unsaturated and homogeneous

    D. Unsaturated and heterogeneous

    Answer Explanation

    Because more solute could be added and dissolve, the solution has not yet reached its limit and is considered unsaturated. Because all the solute dissolves, the particles in the mixture are evenly distributed as a homogenous mixture. 

    • mixture is when elements and compounds are physically, but not chemically, combined.
    • homogeneous mixture is when substances mix evenly and it is impossible to see individual components. A heterogeneous mixture is when the substances mix unevenly and it is possible to see individual components.
    • solution is a type of homogeneous mixture that is formed when a solute dissolves in a solvent.
    • The concentration of a solution is the amount of a substance in a given amount of solution. An unsaturated solution has the ability to dissolve more solute and a saturated solution has already reached the limit of solute it can dissolve.