Which of the following is an example of an exothermic reaction?

A. Melting ice

B. Burning wood

C. Cooking an egg

D. Dissolving sugar in water

Answer 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.

Endothermic and Exothermic Chemical Reactions

Therefore, the Correct Answer is B.

Q #1: What is the difference between innate and adaptive immunity?

A. Innate immunity is present at birth while adaptive immunity is acquired after exposure to pathogens.

B. Innate immunity is specific to particular pathogens while adaptive immunity is nonspecific.

C. Innate immunity is mediated by antibodies while adaptive immunity is mediated by T cells.

D. Innate immunity provides long-term protection while adaptive immunity provides only short-term protection.

Answer Explanation

Innate immunity and adaptive immunity are two arms of the immune system that work together to protect the body from pathogens. Innate immunity is the first line of defense and is present at birth. It includes physical and chemical barriers such as the skin, mucous membranes, and antimicrobial peptides, as well as cells such as macrophages and natural killer cells that can quickly recognize and atack pathogens. Innate immunity is nonspecific, meaning it responds to a wide variety of pathogens in a similar way.

Adaptive immunity, on the other hand, is acquired after exposure to pathogens. It involves the production of antibodies and activation of T cells, which are specific to particular pathogens. Adaptive immunity takes longer to develop than innate immunity, but it provides a more specific and targeted response to pathogens. Once the adaptive immune system has been activated against a particular pathogen, it can provide long-term protection against future infections with that pathogen.

Option b) is incorrect because innate immunity is nonspecific while adaptive immunity is specific. Option c) is incorrect because antibodies are a part of adaptive immunity while T cells can be a part of both innate and adaptive immunity. Option d) is incorrect because adaptive immunity can provide long-term protection, while innate immunity provides immediate but short-lived protection.
Q #2: Which of the following types of RNA carries amino acids to the ribosome during protein synthesis?

A. Messenger RNA

B. Ribosomal RNA

C. Transfer RNA

D. Small nuclear RNA

Answer 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.
Q #3: 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:
1. 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.
Q #4: What is the function of ribosomes in a cell?

A. To produce energy for the cell

B. To store genetic information

C. To transport molecules within the cell

D. To synthesize proteins in the cell

Answer Explanation

Ribosomes are small, spherical structures found in all living cells, including bacteria, archaea, and eukaryotes. Their primary function is to synthesize proteins using the genetic information stored in the cell's DNA. Ribosomes are composed of two subunits, one large and one small, that come together during protein synthesis.

Ribosomes read the genetic information stored in mRNA (messenger RNA) and use this information to assemble amino acids in the correct order to form a protein. The ribosome moves along the mRNA, adding one amino acid at a time to the growing protein chain until it reaches the end of the mRNA and the protein is complete.

Proteins are essential for a wide variety of cellular functions, including catalyzing chemical reactions, providing structural support, and transporting molecules across cell membranes. Therefore, ribosomes play a critical role in the overall function and survival of a cell.
Q #5: What is the name of the hormone that regulates blood sugar levels in the human body?

A. Insulin

B. Glucagon

C. Estrogen

D. Testosterone

Answer 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.
Q #6: What is the difference between innate immunity and adaptive immunity?

A. Innate immunity is present at birth and provides immediate, non-specific protection against pathogens while adaptive immunity is developed over time and provides specific protection against particular pathogens.

B. Innate immunity involves the recognition of specific pathogens while adaptive immunity involves the recognition of general paterns of pathogens.

C. Innate immunity involves the production of antibodies while adaptive immunity involves the activation of phagocytes.

D. Innate immunity is activated by the lymphatic system while adaptive immunity is activated by the circulatory system.

Answer Explanation

Innate immunity is the first line of defense against pathogens and is present at birth. It provides immediate, non-specific protection against a wide range of pathogens, including bacteria, viruses, and fungi. Innate immunity involves physical barriers, such as skin and mucous membranes, as well as cellular and molecular components, such as phagocytes and cytokines.

Adaptive immunity, on the other hand, is developed over time and provides specific protection against particular pathogens. It involves the recognition of antigens, which are specific components of pathogens, by immune cells called lymphocytes. The lymphocytes then produce antibodies that are specific to the antigens, allowing for a targeted response to the pathogen. This process takes time to develop, as the immune system needs to encounter the pathogen and mount a response.

Overall, innate immunity provides immediate, non-specific protection while adaptive immunity provides specific protection that is tailored to the particular pathogen. Both forms of immunity work together to protect the body against pathogens.
Q #7: What is the name of the joint that allows for rotation of the arm at the shoulder?

A. Elbow joint

B. Hip joint

C. Knee joint

D. Shoulder joint

Answer Explanation
Q #8: Which of the following is a type of genetic mutation that involves the insertion or deletion of one or more nucleotides in a DNA sequence?

A. Silent mutation

B. Nonsense mutation

C. Frameshift mutation

D. Missense mutation

Answer Explanation

A frameshift mutation is a type of genetic mutation that involves the insertion or deletion of one or more nucleotides in a DNA sequence. This can cause a shift in the reading frame of the genetic code, resulting in a change in the amino acid sequence of the resulting protein. Frameshift mutations can have significant effects on the function of the protein and can lead to genetic disorders or diseases.
Q #9: What are the steps involved in the scientific method?

A. Observation, hypothesis, prediction, experimentation, analysis, conclusion.

B. Hypothesis, observation, prediction, experimentation, analysis, conclusion.

C. Prediction, observation, experimentation, analysis, conclusion, hypothesis.

D. Observation, data collection, analysis, experimentation, hypothesis, conclusion.
Answer 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:
1. Observation: This is the first step in the scientific method. It involves observing a phenomenon or a problem and gathering information about it.
2. 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.
Q #10: What is the chemical formula for water?

A. H2O

B. CO2

C. NaCl

D. C6H12O6

Answer Explanation

The chemical formula for water is H2O. It consists of two hydrogen atoms and one oxygen atom.