BIOD 151 Final Exam
1. What is the basic unit of life?
Answer: The cell is the basic unit of life.
2. What are the four major macromolecules found in living organisms?
Answer: The four major macromolecules are carbohydrates, lipids, proteins, and
nucleic acids.
3. Explain the difference between prokaryotic and eukaryotic cells.
Answer:
,Prokaryotic cells are unicellular organisms that do not have a nucleus or membrane-
bound organelles. Example: bacteria.
Eukaryotic cells have a nucleus and membrane-bound organelles. They can be
unicellular or multicellular. Example: plant and animal cells.
4. What is the function of ribosomes in the cell?
Answer: Ribosomes are responsible for protein synthesis. They read messenger RNA
(mRNA) and translate it into a polypeptide chain.
5. What is the role of enzymes in biological reactions?
Answer: Enzymes act as catalysts, speeding up chemical reactions without being
consumed in the process. They lower the activation energy required for a reaction to
occur.
6. Describe the process of photosynthesis.
Answer: Photosynthesis is the process by which plants, algae, and some bacteria
convert light energy into chemical energy. It occurs in two stages:
Light-dependent reactions take place in the thylakoid membranes of chloroplasts,
converting light energy into ATP and NADPH.
Calvin cycle (light-independent reactions) occurs in the stroma, using ATP and
NADPH to fix carbon dioxide into glucose.
7. What is the structure of DNA?
Answer: DNA consists of two long strands of nucleotides that form a double helix.
Each nucleotide contains a phosphate group, a deoxyribose sugar, and one of four
nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
8. What is the difference between mitosis and meiosis?
Answer:
Mitosis is a type of cell division that results in two genetically identical daughter
cells, used for growth, repair, and asexual reproduction.
, Meiosis is a type of cell division that reduces the chromosome number by half,
producing four non-identical daughter cells, which are gametes (sperm and eggs).
9. What are the components of the cell membrane?
Answer: The cell membrane is composed of a phospholipid bilayer, proteins,
cholesterol, and carbohydrates. The bilayer provides a semi-permeable barrier, while
proteins allow for transport and communication.
10. What is an allele?
Answer: An allele is a variant form of a gene. Each individual has two alleles for each
gene, one inherited from each parent.11. What is the difference between an
autotroph and a heterotroph?
Answer:
Autotrophs are organisms that produce their own food through processes like
photosynthesis (e.g., plants).
Heterotrophs cannot produce their own food and must consume other organisms for
energy (e.g., animals, fungi).
12. What are the three main components of a nucleotide?
Answer: A nucleotide consists of:
A phosphate group
A five-carbon sugar (deoxyribose in DNA, ribose in RNA)
A nitrogenous base (adenine, thymine, cytosine, guanine, or uracil)
13. What is the function of the mitochondria in eukaryotic cells?
Answer: Mitochondria are the powerhouse of the cell. They generate ATP through
cellular respiration, providing energy for cellular activities.
14. Explain the central dogma of molecular biology.
Answer: The central dogma describes the flow of genetic information in cells:
DNA is transcribed into mRNA.
mRNA is translated into a protein.
1. What is the basic unit of life?
Answer: The cell is the basic unit of life.
2. What are the four major macromolecules found in living organisms?
Answer: The four major macromolecules are carbohydrates, lipids, proteins, and
nucleic acids.
3. Explain the difference between prokaryotic and eukaryotic cells.
Answer:
,Prokaryotic cells are unicellular organisms that do not have a nucleus or membrane-
bound organelles. Example: bacteria.
Eukaryotic cells have a nucleus and membrane-bound organelles. They can be
unicellular or multicellular. Example: plant and animal cells.
4. What is the function of ribosomes in the cell?
Answer: Ribosomes are responsible for protein synthesis. They read messenger RNA
(mRNA) and translate it into a polypeptide chain.
5. What is the role of enzymes in biological reactions?
Answer: Enzymes act as catalysts, speeding up chemical reactions without being
consumed in the process. They lower the activation energy required for a reaction to
occur.
6. Describe the process of photosynthesis.
Answer: Photosynthesis is the process by which plants, algae, and some bacteria
convert light energy into chemical energy. It occurs in two stages:
Light-dependent reactions take place in the thylakoid membranes of chloroplasts,
converting light energy into ATP and NADPH.
Calvin cycle (light-independent reactions) occurs in the stroma, using ATP and
NADPH to fix carbon dioxide into glucose.
7. What is the structure of DNA?
Answer: DNA consists of two long strands of nucleotides that form a double helix.
Each nucleotide contains a phosphate group, a deoxyribose sugar, and one of four
nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
8. What is the difference between mitosis and meiosis?
Answer:
Mitosis is a type of cell division that results in two genetically identical daughter
cells, used for growth, repair, and asexual reproduction.
, Meiosis is a type of cell division that reduces the chromosome number by half,
producing four non-identical daughter cells, which are gametes (sperm and eggs).
9. What are the components of the cell membrane?
Answer: The cell membrane is composed of a phospholipid bilayer, proteins,
cholesterol, and carbohydrates. The bilayer provides a semi-permeable barrier, while
proteins allow for transport and communication.
10. What is an allele?
Answer: An allele is a variant form of a gene. Each individual has two alleles for each
gene, one inherited from each parent.11. What is the difference between an
autotroph and a heterotroph?
Answer:
Autotrophs are organisms that produce their own food through processes like
photosynthesis (e.g., plants).
Heterotrophs cannot produce their own food and must consume other organisms for
energy (e.g., animals, fungi).
12. What are the three main components of a nucleotide?
Answer: A nucleotide consists of:
A phosphate group
A five-carbon sugar (deoxyribose in DNA, ribose in RNA)
A nitrogenous base (adenine, thymine, cytosine, guanine, or uracil)
13. What is the function of the mitochondria in eukaryotic cells?
Answer: Mitochondria are the powerhouse of the cell. They generate ATP through
cellular respiration, providing energy for cellular activities.
14. Explain the central dogma of molecular biology.
Answer: The central dogma describes the flow of genetic information in cells:
DNA is transcribed into mRNA.
mRNA is translated into a protein.
