Intro to Cell Biology

1.What function does the mitochondrion perform in the cell? 

• A) Synthesizes proteins

  
  

• B) Converts solar energy into chemical energy

• C) Provides the cell with energy by synthesizing ATP

  
  

• D) Stores genetic information

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  E) Transports molecules within the cell

2. Which of the following statements correctly describes the structure of a prokaryotic cell?

• A) Prokaryotes have organized mitochondria that perform respiration

• B) Their genetic material is not divided into chromosomes and is found in the nucleus

  
  

• C) Prokaryotes have a single circular DNA molecule located in an area called the nucleoid 

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  D) Prokaryotes contain membrane-bound organelles like the endoplasmic reticulum and Golgi apparatus

• E) All prokaryotes have a cell wall made entirely of cellulose

  
  

3. What is the main role of the Krebs cycle in the cell?

• A) Synthesis of glycogen

• B) Conversion of chemical energy from carbohydrates into ATP molecules 

• C) Breakdown of proteins into amino acids

• D) Detoxification of metabolic waste products

  
  

• E) Synthesis of amino acids and nucleotides

  
  

4. What role does the Golgi apparatus play in the cell?

• A) Synthesizes ATP

• B) Modifies and transports proteins and lipids

• C) Stores genetic information

• D) Participates in cell division

• E) Handles the recycling of cell waste

  
  

5. What process occurs in the endoplasmic reticulum (ER), depending on its type? 

• A) Synthesis of proteins and lipids (smooth ER) and protein modification (rough ER)

• B) Synthesis of ATP for the cell

• C) Participation in cell division

• D) Degradation of toxins and protein breakdown

• E) Formation and transport of vesicles

6. Which type of bond between molecules is responsible for the formation of the double helix structure of DNA?

• A) lonic bonds

• B) Covalent bonds

• C) Hydrogen bonds

• D) Disulfide bonds

• E) Phosphodiester bonds

7. Why are cell membranes, composed of phospholipids, semipermeable?

• A) Due to the hydrophilic heads that allow all molecules to pass

  
  

• B) Because phospholipids form a continuous film that prevents molecules from passing 

  
  

• C) Due to the hydrophobic tails of phospholipids, which create a barrier for water-soluble substances

• D) Due to the presence of ion channels that only allow charged molecules to pass

• E) Because the membrane is coated with carbohydrates that block molecule permeability

  Answer: C

8. Which of the following statements about cell division (mitosis) is incorrect?

• A) In mitosis, chromosome duplication occurs

• B) During mitosis, sister chromatids are separated into opposite poles of the cell

• C) Mitosis includes stages such as interphase, prophase, metaphase, anaphase, and telophase

• D) Mitosis results in the formation of two daughter cells with a complete set of chromosomes

  
  

•  E) Mitosis only occurs in germ cells

9. What effect does an increase in calcium concentration in the cytoplasm have on the cell?

• A) It initiates apoptosis (programmed cell death)

• B) It activates the synthesis of proteins necessary for cell regeneration

• C) It decreases the permeability of the cell membrane

  
  

• D) It inhibits the functioning of mitochondria and decreases ATP production

• E) It participates in the activation of phagocytosis and cell signaling

  
  

10. Which molecules play a key role in regulating the cell cycle and controlling the transitions between its phases?

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Answer: A

• A) Kinases and cyclins

  
  

• B) Transport molecules and membrane proteins

  
  

• C) Hormones and antigen molecules

•  D) Ribosomes and tRNA

• E) Mitochondria and peroxisomes