Questions Flashcards
Which of the following is a difference between prokaryotic and eukaryotic cells?
(A) Prokaryotic cells have membrane-bound organelles; eukaryotic cells do not.
(B) Prokaryotic cells have circular DNA; eukaryotic cells have linear DNA.
(C) Prokaryotic cells have a nucleus; eukaryotic cells do not.
(D) Both prokaryotic and eukaryotic cells are multicellular organisms.
(B) Prokaryotic cells have circular DNA; eukaryotic cells have linear DNA.
Prokaryotic cells lack membrane-bound organelles, including a nucleus, and have circular DNA. In contrast, eukaryotic cells have membrane-bound organelles, including a nucleus, and their DNA is linear.
Compare two structural or functional differences between prokaryotic and eukaryotic cells.
- Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a nucleus.
- Prokaryotic cells have circular DNA, while eukaryotic cells have linear DNA stored in chromosomes.
What is the main function of the Golgi apparatus?
(A) Protein synthesis
(B) Lipid storage
(C) Modifying and packaging proteins
(D) Energy production
C
Describe the function of lysosomes in the cell.
- Lysosomes contain enzymes to break down macromolecules and cellular waste.
- They play a role in recycling cell materials and apoptosis.
Differentiation involves:
(A) DNA replication
(B) Specialisation into specific cell types
(C) Gene loss
(D) Programmed cell death
B
Explain how stem cells contribute to tissue repair.
- Stem cells divide and differentiate to replace damaged cells.
- This ensures the restoration of tissue function.
- For example, skin stem cells regenerate epidermal layers after injury.
Which stem cells can produce all cell types, including extra-embryonic tissues?
(A) Unipotent
(B) Totipotent
(C) Pluripotent
(D) Multipotent
B
Distinguish between totipotent and pluripotent stem cells.
- Totipotent cells differentiate into all cell types, including extra-embryonic tissues, whereas pluripotent cells can differentiate into all cell types except extra-embryonic tissues
Which system breaks down food for absorption?
(A) Respiratory
(B) Circulatory
(C) Digestive
(D) Excretory
C
Explain how the digestive and circulatory systems interact to deliver nutrients to cells.
- The digestive system breaks down food into absorbable molecules like glucose.
- These molecules are absorbed into the bloodstream from the small intestine.
- The circulatory system distributes the nutrients to cells for energy and growth.
Why is a high SA:V ratio beneficial for cells in certain tissues?
(A) Reduces energy expenditure
(B) Increases diffusion efficiency
(C) Improves DNA replication
(D) Promotes active transport only
B
Describe how the abundance of mitochondria in muscle cells supports their function.
- Muscle cells require large amounts of energy for contraction, provided by ATP.
- Mitochondria are the site of aerobic respiration, producing ATP efficiently.
What is the primary role of phospholipids in the cell membrane?
(A) Act as enzymes
(B) Form a bilayer that provides selective permeability
(C) Transport molecules across the membrane
(D) Maintain cell rigidity
B
Describe how the structure of the phospholipid bilayer contributes to the cell membrane’s function
- The bilayer’s hydrophilic heads face outward, interacting with the aqueous environment.
- The hydrophobic tails face inward, creating a barrier to water-soluble substances.
- This structure allows selective permeability for substances like gases and small molecules.
Which process moves water across a selectively permeable membrane?
(A) Osmosis
(B) Diffusion
(C) Active transport
(D) Exocytosis
A
Explain how facilitated diffusion differs from simple diffusion in moving substances across the cell membrane.
- Simple diffusion occurs directly through the phospholipid bilayer without proteins.
- Facilitated diffusion requires protein channels or carriers for transport of larger or charged molecules.
