What is the name of the genetic disorder caused by the presence of an extra chromosome 21?
Turner syndrome
Klinefelter syndrome
Down syndrome
Huntington's disease
Correct Answer : C
Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21. It is also known as trisomy 21, because affected individuals have three copies of chromosome 21 instead of the normal two.
The extra chromosome 21 in Down syndrome occurs due to a random error in cell division, which leads to the production of an abnormal gamete (egg or sperm) with an extra copy of the chromosome. When this gamete fuses with a normal gamete during fertilization, the resulting zygote has 47 chromosomes instead of the usual 46, and develops into a fetus with Down syndrome.
Down syndrome is characterized by a range of physical and intellectual symptoms, including developmental delays, intellectual disability, distinctive facial features, heart defects, and increased risk of certain medical conditions such as leukemia and Alzheimer's disease. However, the severity and expression of these symptoms can vary widely among affected individuals.
![]() |
TEAS 7 Exam Quiz Bank
HESI A2 Exam Quiz Bank
Find More Questions 📚
Teas 7 Questions: We got the latest updated TEAS 7 questions
100% Money Refund: 100% money back guarantee if you take our full
assessment pass with 80% and fail the actual exam.
Live Tutoring: Fully customized live tutoring lessons.
Guaranteed A Grade: All students who use our services pass with 90%
guarantee.
Related Questions
Correct Answer is C
Explanation
Transfer RNA (tRNA) is a type of RNA molecule that carries amino acids to the ribosome during protein synthesis. Each tRNA molecule has a specific sequence of three nucleotides called an anticodon, which pairs with a complementary codon in the messenger RNA (mRNA) sequence. Each tRNA also carries a specific amino acid that corresponds to the codon it recognizes, allowing the ribosome to link the amino acids together in the correct order to form a protein.
In contrast, messenger RNA (mRNA) carries the genetic information from the DNA to the ribosome, where it serves as a template for protein synthesis. Ribosomal RNA (rRNA) is a component of the ribosome itself, where it helps to catalyze the formation of peptide bonds between amino acids. Small nuclear RNA (snRNA) is involved in splicing of pre-mRNA molecules during post-transcriptional processing.
![]() |
Correct Answer is B
Explanation
Exothermic reactions are reactions that release energy in the form of heat, light, or sound. Burning wood is an example of an exothermic reaction because it releases heat and light. As the wood reacts with oxygen in the air, it undergoes a combustion reaction that releases energy in the form of heat and light. Melting ice is an endothermic reaction because it requires energy input to melt the solid ice into liquid water. Cooking an egg is a chemical reaction that involves denaturing the proteins in the egg, but it is not necessarily exothermic or endothermic. Dissolving sugar in water is also not an example of an exothermic reaction because it does not release energy in the form of heat, light, or sound.

Correct Answer is A
Explanation
The kidneys secrete a number of hormones, which are important for normal functioning of the body.
If blood pressure falls, renin is secreted by the kidneys to constrict the small blood vessels, thereby increasing blood pressure. If the kidneys aren’t functioning correctly, too much renin can be produced, increasing blood pressure and sometimes resulting in hypertension (high blood pressure). This is why a number of people with kidney diseases also have high blood pressure.
Correct Answer is A
Explanation
- Enzymatic reactions follow a Michaelis-Menten curve.
- As substrate concentration increases, the reaction rate initially increases rapidly.
- However, at high substrate concentrations, the enzyme becomes saturated, meaning all active sites are occupied, and adding more substrate does not increase the reaction rate further.
- This leads to a plateau in reaction rate, which is represented by line A.
Analysis of the Other Lines:
- B: Shows a linear decrease, which does not represent enzyme kinetics. ❌
- C: Depicts a constant reaction rate independent of substrate concentration, which is incorrect. ❌
- D: Shows a decreasing reaction rate, which does not align with enzyme behavior. ❌
Correct Answer is A
Explanation
The scientific method is a systematic approach used to answer questions or test hypotheses about the natural world. The steps involved in the scientific method are:
- Observation: This is the first step in the scientific method. It involves observing a phenomenon or a problem and gathering information about it.
- Hypothesis: After making an observation, a scientist forms a hypothesis, which is a tentative explanation for the phenomenon or problem.
3. Prediction: Based on the hypothesis, the scientist makes a prediction about what will happen in an experiment or what they will observe.
4. Experimentation: The scientist designs and conducts an experiment to test the hypothesis and prediction.
5. Analysis: The data collected from the experiment are analyzed to determine if they support or refute the hypothesis.
6. Conclusion: Based on the analysis of the data, the scientist draws a conclusion about whether the hypothesis is supported or refuted.
Option b) is incorrect because it starts with hypothesis before observation. Option c) is incorrect because prediction comes before experimentation. Option d) is incorrect because hypothesis comes after observation and data collection.
![]() |
Correct Answer is C
Explanation
One of the main funcons of the respiratory system is to facilitate the exchange of gases between the body and the environment. During inhalaon, air enters the lungs and oxygen is absorbed into the bloodstream. During exhalaon, carbon dioxide is removed from the body and expelled into the environment.

Correct Answer is D
Explanation
Exocrine glandular is not one of the four primary ssue types found in the human body. The four primary ssue types are epithelial, nervous, connective, and muscle.

Correct Answer is A
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.
2. 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.
3. 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.
4. 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.
5. 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.
![]() |
Correct Answer is A
Explanation
Insulin is a hormone produced by the pancreas that plays a crucial role in regulating the levels of glucose (sugar) in the blood. After a person eats a meal, the levels of glucose in the blood rise, which stimulates the pancreas to release insulin into the bloodstream. Insulin acts on various cells in the body, particularly those in the liver, muscles, and adipose tissue, to promote the uptake, use, and storage of glucose.
Insulin helps to lower the levels of glucose in the blood by increasing the uptake of glucose by cells, stimulating the liver and muscle cells to store glucose in the form of glycogen, and inhibiting the production and release of glucose by the liver. This process is known as glucose homeostasis, and it helps to keep the levels of glucose in the blood within a normal range.
Deficiencies or abnormalities in insulin production or function can lead to a range of metabolic disorders, including type 1 and type 2 diabetes. In type 1 diabetes, the body does not produce enough insulin, while in type 2 diabetes, the body becomes resistant to the effects of insulin, leading to elevated levels of glucose in the blood.

Correct Answer is D
Explanation
- A. Adduction → Moving a limb toward the midline of the body. ❌
- B. Extension → Increasing the angle of a joint (e.g., straightening the arm or leg). ❌
- C. Flexion → Decreasing the angle of a joint (e.g., bending the elbow or knee). ❌
- D. Abduction → Moving a limb away from the midline (e.g., raising the arm or leg sideways). ✅
This question was extracted from the actual TEAS Exam. Ace your TEAS exam with the actual TEAS 7 questions, Start your journey with us today
Visit Naxlex, the Most Trusted TEAS TEST Platform With Guaranteed Pass of 90%.
Money back guarantee if you use our service and fail the actual exam. Option of personalised live tutor on your area of weakness.



