Lab midterm bio 181 GCU QUESTIONS WITH
COMPLETE SOLUTIONS
Course
BIO 181L
1. What are the differences between prokaryotic and eukaryotic cells?
Solution:
Prokaryotic cells: No nucleus, smaller, lack membrane-bound organelles (e.g., bacteria).
Eukaryotic cells: Have a nucleus, larger, contain membrane-bound organelles (e.g.,
plants, animals).
Rationale:
The presence of a nucleus and organelles is the key distinguishing feature between these cell
types.
2. What is the function of the mitochondria?
Solution:
The mitochondria are the "powerhouses" of the cell.
They generate ATP through cellular respiration.
ATP is the primary energy carrier for cellular processes.
Rationale:
Cells need energy for survival, and mitochondria provide it by breaking down glucose.
3. How does osmosis differ from diffusion?
Solution:
Osmosis: Movement of water across a selectively permeable membrane from low to
high solute concentration.
Diffusion: Movement of molecules from high to low concentration, no membrane
required.
Rationale:
Osmosis is a special type of diffusion focusing specifically on water movement.
,4. What are the four main macromolecules and their functions?
Solution:
1. Carbohydrates – Provide quick energy (e.g., glucose, starch).
2. Proteins – Support structure, enzymes, and muscle movement (e.g., hemoglobin).
3. Lipids – Store energy and make up cell membranes (e.g., fats, phospholipids).
4. Nucleic Acids – Store genetic information (DNA and RNA).
Rationale:
Each macromolecule plays a vital role in cellular function and metabolism.
5. What is the structure of DNA?
Solution:
Double-helix shape.
Composed of nucleotides (sugar, phosphate, nitrogen base).
Bases: Adenine (A) pairs with Thymine (T), Cytosine (C) pairs with Guanine (G).
Rationale:
DNA's structure allows for accurate replication and genetic coding.
6. What happens during each phase of mitosis?
Solution:
1. Prophase – Chromosomes condense, nuclear envelope breaks down.
2. Metaphase – Chromosomes align in the middle of the cell.
3. Anaphase – Sister chromatids separate and move to opposite sides.
4. Telophase – New nuclei form, and cytokinesis begins.
Rationale:
Mitosis ensures that daughter cells receive the same genetic information.
7. How do enzymes speed up chemical reactions?
Solution:
, Enzymes lower activation energy, making reactions faster.
They are specific to substrates.
Example: Amylase breaks down starch into sugar.
Rationale:
Enzymes are biological catalysts essential for metabolism and digestion.
8. What are the three main types of microscopes and their uses?
Solution:
1. Light Microscope – Used for living cells and simple tissue samples.
2. Scanning Electron Microscope (SEM) – Produces detailed surface images.
3. Transmission Electron Microscope (TEM) – Shows internal cell structures at high
resolution.
Rationale:
Different microscopes provide different levels of detail, from basic observation to molecular
imaging.
9. What is the role of chloroplasts in plant cells?
Solution:
Chloroplasts contain chlorophyll, which absorbs light for photosynthesis.
Convert light energy into glucose and oxygen.
Occur only in plant cells.
Rationale:
Chloroplasts are crucial for converting sunlight into energy, supporting plant life.
10. What are the differences between passive and active transport?
Solution:
Passive Transport: No energy required; includes diffusion, osmosis, facilitated
diffusion.
, Active Transport: Requires energy (ATP) to move substances against the concentration
gradient (e.g., sodium-potassium pump).
Rationale:
Cells use different transport methods based on energy needs and concentration gradients.
11. What are the key differences between plant and animal cells?
Solution:
Plant cells: Have a cell wall, chloroplasts, and a large central vacuole.
Animal cells: Lack a cell wall, have centrioles, and smaller vacuoles.
Rationale:
Plant cells are adapted for photosynthesis and structure, while animal cells are more flexible.
12. What happens to a red blood cell in a hypertonic, hypotonic, and isotonic solution?
Solution:
Hypertonic: Water moves out; the cell shrivels (crenation).
Hypotonic: Water moves in; the cell swells and may burst (lysis).
Isotonic: Water moves equally; the cell stays the same.
Rationale:
Osmosis affects cells based on solute concentrations inside and outside the cell.
13. What is the function of ribosomes?
Solution:
Ribosomes synthesize proteins by translating mRNA into amino acid sequences.
Can be free-floating in cytoplasm or attached to the rough ER.
Rationale:
Ribosomes are essential for protein production, which supports cell function and growth.
14. What are the three main parts of a nucleotide?
Solution:
1. Sugar (Deoxyribose in DNA, Ribose in RNA).
COMPLETE SOLUTIONS
Course
BIO 181L
1. What are the differences between prokaryotic and eukaryotic cells?
Solution:
Prokaryotic cells: No nucleus, smaller, lack membrane-bound organelles (e.g., bacteria).
Eukaryotic cells: Have a nucleus, larger, contain membrane-bound organelles (e.g.,
plants, animals).
Rationale:
The presence of a nucleus and organelles is the key distinguishing feature between these cell
types.
2. What is the function of the mitochondria?
Solution:
The mitochondria are the "powerhouses" of the cell.
They generate ATP through cellular respiration.
ATP is the primary energy carrier for cellular processes.
Rationale:
Cells need energy for survival, and mitochondria provide it by breaking down glucose.
3. How does osmosis differ from diffusion?
Solution:
Osmosis: Movement of water across a selectively permeable membrane from low to
high solute concentration.
Diffusion: Movement of molecules from high to low concentration, no membrane
required.
Rationale:
Osmosis is a special type of diffusion focusing specifically on water movement.
,4. What are the four main macromolecules and their functions?
Solution:
1. Carbohydrates – Provide quick energy (e.g., glucose, starch).
2. Proteins – Support structure, enzymes, and muscle movement (e.g., hemoglobin).
3. Lipids – Store energy and make up cell membranes (e.g., fats, phospholipids).
4. Nucleic Acids – Store genetic information (DNA and RNA).
Rationale:
Each macromolecule plays a vital role in cellular function and metabolism.
5. What is the structure of DNA?
Solution:
Double-helix shape.
Composed of nucleotides (sugar, phosphate, nitrogen base).
Bases: Adenine (A) pairs with Thymine (T), Cytosine (C) pairs with Guanine (G).
Rationale:
DNA's structure allows for accurate replication and genetic coding.
6. What happens during each phase of mitosis?
Solution:
1. Prophase – Chromosomes condense, nuclear envelope breaks down.
2. Metaphase – Chromosomes align in the middle of the cell.
3. Anaphase – Sister chromatids separate and move to opposite sides.
4. Telophase – New nuclei form, and cytokinesis begins.
Rationale:
Mitosis ensures that daughter cells receive the same genetic information.
7. How do enzymes speed up chemical reactions?
Solution:
, Enzymes lower activation energy, making reactions faster.
They are specific to substrates.
Example: Amylase breaks down starch into sugar.
Rationale:
Enzymes are biological catalysts essential for metabolism and digestion.
8. What are the three main types of microscopes and their uses?
Solution:
1. Light Microscope – Used for living cells and simple tissue samples.
2. Scanning Electron Microscope (SEM) – Produces detailed surface images.
3. Transmission Electron Microscope (TEM) – Shows internal cell structures at high
resolution.
Rationale:
Different microscopes provide different levels of detail, from basic observation to molecular
imaging.
9. What is the role of chloroplasts in plant cells?
Solution:
Chloroplasts contain chlorophyll, which absorbs light for photosynthesis.
Convert light energy into glucose and oxygen.
Occur only in plant cells.
Rationale:
Chloroplasts are crucial for converting sunlight into energy, supporting plant life.
10. What are the differences between passive and active transport?
Solution:
Passive Transport: No energy required; includes diffusion, osmosis, facilitated
diffusion.
, Active Transport: Requires energy (ATP) to move substances against the concentration
gradient (e.g., sodium-potassium pump).
Rationale:
Cells use different transport methods based on energy needs and concentration gradients.
11. What are the key differences between plant and animal cells?
Solution:
Plant cells: Have a cell wall, chloroplasts, and a large central vacuole.
Animal cells: Lack a cell wall, have centrioles, and smaller vacuoles.
Rationale:
Plant cells are adapted for photosynthesis and structure, while animal cells are more flexible.
12. What happens to a red blood cell in a hypertonic, hypotonic, and isotonic solution?
Solution:
Hypertonic: Water moves out; the cell shrivels (crenation).
Hypotonic: Water moves in; the cell swells and may burst (lysis).
Isotonic: Water moves equally; the cell stays the same.
Rationale:
Osmosis affects cells based on solute concentrations inside and outside the cell.
13. What is the function of ribosomes?
Solution:
Ribosomes synthesize proteins by translating mRNA into amino acid sequences.
Can be free-floating in cytoplasm or attached to the rough ER.
Rationale:
Ribosomes are essential for protein production, which supports cell function and growth.
14. What are the three main parts of a nucleotide?
Solution:
1. Sugar (Deoxyribose in DNA, Ribose in RNA).
