HESI A2 Biology Practice Test Exam 2025 Updated Questions and Answers
1. Hierarchic Organizational system for nomenclature: Kingdom Phylum
Class
Order
Family
Genus
Species (Least)
"Keep Penguins Cool Or Find Good Shelter"
2. Scientific Method: Observation
Hypothesis
Experiment
Conclusion
3. Water: All life, and therefore biology , occurs in water.
4. Properties of Water: 2 Hydrogen bonds Covalently bonded to Oxygen.
Hydrogen Bonding between molecules.
- High specific heat
- Large bodies or water stabilize climates
- Strong cohesive and adhesive properties
,- Water freezes forms a lattice crystal resulting in ice floating in wat er.
- Polarity of water allows it to act as a universal solvent.
- Water can be used to dissolve different solvents.
5. Carbohydrates: Long chains, or polymers of sugar. Most importantl y form the
backbone of DNA and RNA.
6. Lipids: Fats (Saturated and Unsaturated)
Steroids, lipids and fats
, 7. Saturated fat: Clogs arteries. No double bonds in their hydrocarb room on tail. Solid at
temperature.
8. Unsaturated fat: Double bond in their hydrocarbon tail. Liquid at r ture. oom tempera-
9. Phospholipids: Phosphate group (polar) soluble in water. Hydroc fatty arbon tail of
acids is nonpolar and nonsoluble in water.
Ex. Cell Membrane
10. Steroids: Are lipids, which are precursors to hormones and dru gs
11. Proteins: They are Polymers of 20 molecules called Amino Acids. a type of Enzymes are
gest Biological
protein, which catalyze different reactions or processes. Lar Molecule
12. Metabolism: Sum of all chemical reactions that occur in an organism.
- High energy to low energy.
- All reactions are catabolyzed by enzymes
13. Cell: Fundamental unit of biology
14. Prokaryotic Cells: Lack defined nucleus and do not contain me mbrane- bound
organelles.
1. Hierarchic Organizational system for nomenclature: Kingdom Phylum
Class
Order
Family
Genus
Species (Least)
"Keep Penguins Cool Or Find Good Shelter"
2. Scientific Method: Observation
Hypothesis
Experiment
Conclusion
3. Water: All life, and therefore biology , occurs in water.
4. Properties of Water: 2 Hydrogen bonds Covalently bonded to Oxygen.
Hydrogen Bonding between molecules.
- High specific heat
- Large bodies or water stabilize climates
- Strong cohesive and adhesive properties
,- Water freezes forms a lattice crystal resulting in ice floating in wat er.
- Polarity of water allows it to act as a universal solvent.
- Water can be used to dissolve different solvents.
5. Carbohydrates: Long chains, or polymers of sugar. Most importantl y form the
backbone of DNA and RNA.
6. Lipids: Fats (Saturated and Unsaturated)
Steroids, lipids and fats
, 7. Saturated fat: Clogs arteries. No double bonds in their hydrocarb room on tail. Solid at
temperature.
8. Unsaturated fat: Double bond in their hydrocarbon tail. Liquid at r ture. oom tempera-
9. Phospholipids: Phosphate group (polar) soluble in water. Hydroc fatty arbon tail of
acids is nonpolar and nonsoluble in water.
Ex. Cell Membrane
10. Steroids: Are lipids, which are precursors to hormones and dru gs
11. Proteins: They are Polymers of 20 molecules called Amino Acids. a type of Enzymes are
gest Biological
protein, which catalyze different reactions or processes. Lar Molecule
12. Metabolism: Sum of all chemical reactions that occur in an organism.
- High energy to low energy.
- All reactions are catabolyzed by enzymes
13. Cell: Fundamental unit of biology
14. Prokaryotic Cells: Lack defined nucleus and do not contain me mbrane- bound
organelles.
