Question

8-The _________ form the surface of an atom and participate in forming covalent bonds.

a. neutrons and electrons

b. protons

c. neutrons

d. protons and neutrons

e. electrons

10-Failure of cell cycle check points can cause ________.

a. Increased chance of cancer

b. Increased mutation rates

c. Benign tumors

d. All of these

e. Unregulated cell division

11-Which is the lowest level of biological organization that shows the emergent property we consider “life”?

a. Population

b. Cell

c. Community

d. Molecule

e. Organism

14-Why are sweating and other body-cooling mechanisms necessary during vigorous exercise?

a. A byproduct of respiration is heat

b. About twice as much energy is released as heat than is made into ATP units

c. The human body overheats at about 100 degrees Farenheight.

d. So much heat is released by cellular respiration during exercise that the body is in danger of overheating.

e. Muscle movement causes friction

17-A measurement included in the outcome of an experiment is called an ________.

a. independent variable

b. Control

c. dependent Variable

d. Hypothesis

e. Experiment

21Dissolving NaOH in neutral water causes a dramatic change in pH because of __________.

a. the increase in OH- concentration

b. the decrease in OH- concentration

c. the increase in H+ concentration

d. the increase in Na+ concentration

23-What type of junction is associated with attaching adjacent cells to form tissues?

a. Gap junction

b. Petticoat junction

c. Anchoring junction

d. Tight junction

24-The genetic material is made of ___________.

a. carbohydrate

b. protein

c. lipid

d. nucleic acid

Answer 1

8. Answer: e

• Nucleus of an atom comprises of two sub-atomic parts: protons and neutrons.
• The neutrons have no charge, while protons have positive charge.
• Electrons are negatively charged, located in the electron cloud surrounding the nucleus of an atom.
• The electrons in an atom are involved in bond formation.
• Covalent bonds are formed by sharing of electrons. In covalent bonds non-metals share electrons to achieve lower energy state.

10. Answer: d

• Genes, referred to as protooncogenes, promotes cell division.
• While, tumor suppressor genes inhibit the genes under normal conditions.
• If tumor suppressor genes are mutated or lose function, the cell division becomes uncontrolled and tumor/cancer is resulted.
• A single allele mutation may result in proto-oncogene.
• RAS is a protooncogene, mutation that may convert it to oncogene, may be by substitution of Glycine at position 12, with any amino acid, which results in decreased GTP activity and GTP hydrolysis.

11. Answer: b

• Cell comprises of the smallest structural and functional unit of life.
• Such as observed in many unicellular organisms like bacteria.

14. Answer: b

• During exercise, body needs extra energy.
• For muscle contraction for about 4-6 seconds, muscle stores ATP, which is used.
• But for further ATP supply metabolic pathways, both aerobic and anaerobic, are used.
• However, more than double amount of energy is lost as heat than ATP produced.
• Thus, by thermoregulation, sweating occurs to reduce the heat.

17. Answer: c

• Dependent variable: Variable whose effect is altered due to the variation in the independent variable.
• Thus, the outcome is reflected by the dependent variable.

21. Answer: a

• The acidity or basicity of an aqueous solution is determined by a logarithmic scale of pH.
• pH is measured as negative logarithm (base 10) of molar concentration of Hydrogen ions (unit of moles per liter).
• Solutions with pH value 7- neutral, value<7-acidic, value >7 is basic.
• Dissolving NaOH increases the OH- ions, and the pH increases above 7.

23. Answer: c

• Epithelial cells can transport ions from one cell to adjacent cell.
• Cell junctions form sheets that interconnect the adjacent cells.
• Tight junctions (TJ) forms sealing between the cells by forming a continuous intercellular barrier.
• Communication between the neighbouring cell is achieved by Gap junction.
• Anchoring junctions anchors or binds cells and ECM (extracellular matrix) in tissues.

24. Answer: d

• DNA and RNA are both nucleic acids. RNA is ribonucleic acids. DNA is Deoxyribonucleic acid. The structural monomeric units of both DNA and RNA are nucleotides.
• DNA acts as genetic material for most cells, apart from some viruses (where RNA are genetic materials).