Explain how lysosomes maintain cellular homeostasis and describe what happens when their function is impaired. (2 marks)
--- 5 WORK AREA LINES (style=lined) ---
Aussie Maths & Science Teachers: Save your time with SmarterEd
Explain how lysosomes maintain cellular homeostasis and describe what happens when their function is impaired. (2 marks)
--- 5 WORK AREA LINES (style=lined) ---
→ Lysosomes maintain cellular homeostasis by breaking down waste materials, damaged organelles, and cellular debris using enzymes.
→ This prevents the accumulation of harmful substances.
→ When lysosomal function is impaired, waste products and damaged components build up, leading to cellular dysfunction and potentially contributing to diseases that impair cellular efficiency and overall health.
→ Lysosomes maintain cellular homeostasis by breaking down waste materials, damaged organelles, and cellular debris using enzymes.
→ This prevents the accumulation of harmful substances.
→ When lysosomal function is impaired, waste products and damaged components build up, leading to cellular dysfunction and potentially contributing to diseases that impair cellular efficiency and overall health.
Explain how the cell arrangement supports the role and specific functions of the following cellular structures
--- 4 WORK AREA LINES (style=lined) ---
--- 4 WORK AREA LINES (style=lined) ---
a. Cytoplasm:
→ The cytoplasm is a gel-like substance that fills the cell, providing a medium in which organelles are suspended.
→ It facilitates the movement of materials within the cell and allows biochemical reactions to occur efficiently.
b. Ribosomes:
→ Ribosomes can be found either floating freely in the cytoplasm or attached to the rough endoplasmic reticulum.
→ Their arrangement allows them to efficiently translate mRNA into proteins, with free ribosomes synthesising proteins for use within the cell and membrane-bound ribosomes manufacturing proteins for export or use in the cell membrane.
a. Cytoplasm:
→ The cytoplasm is a gel-like substance that fills the cell, providing a medium in which organelles are suspended.
→ It facilitates the movement of materials within the cell and allows biochemical reactions to occur efficiently.
b. Ribosomes:
→ Ribosomes can be found either floating freely in the cytoplasm or attached to the rough endoplasmic reticulum.
→ Their arrangement allows them to efficiently translate mRNA into proteins, with free ribosomes synthesising proteins for use within the cell and membrane-bound ribosomes manufacturing proteins for export or use in the cell membrane.
Which of the following correctly describes the roles of lysosomes and the Golgi apparatus?
\(C\)
→ Lysosomes contain digestive enzymes that break down cellular waste and debris.
→ Golgi apparatus is responsible for modifying, sorting, and packaging proteins for secretion or use within the cell.
\(\Rightarrow C\)
Which of the following correctly compares the structure and function of the mitochondria and the chloroplast?
\(C\)
→ Mitochondria are responsible for producing ATP through the process of cellular respiration.
→ Chloroplasts, found in plant cells, convert light energy into glucose via photosynthesis.
→ Both organelles have distinct functions related to energy conversion in cells.
\(\Rightarrow C\)
Describe the structure and role of phospholipids in the cell membrane based on the fluid mosaic model. (3 marks)
--- 6 WORK AREA LINES (style=lined) ---
→ In the fluid mosaic model, phospholipids form a bilayer that acts as the fundamental structure of the cell membrane.
→ Each phospholipid has a hydrophilic head that faces outward and a hydrophobic tail that faces inward, creating a barrier that separates the cell’s internal and external environments.
→ This bilayer is semi-permeable, allowing selective substances to pass through while blocking others.
→ In the fluid mosaic model, phospholipids form a bilayer that acts as the fundamental structure of the cell membrane.
→ Each phospholipid has a hydrophilic head that faces outward and a hydrophobic tail that faces inward, creating a barrier that separates the cell’s internal and external environments.
→ This bilayer is semi-permeable, allowing selective substances to pass through while blocking others.
According to the fluid mosaic model of the cell membrane
--- 5 WORK AREA LINES (style=lined) ---
--- 5 WORK AREA LINES (style=lined) ---
a. The phospholipid bilayer:
→ Consists of two layers of phospholipids.
→ One layer involves hydrophilic (water-attracting) heads facing outward toward the water-based environment while the opposite layer has hydrophobic (water-repelling) tails facing inward, away from water.
b. Proteins:
→ are embedded in the double phospholid layer and play a role in the cell structure and communication.
a. The phospholipid bilayer:
→ Consists of two layers of phospholipids.
→ One layer involves hydrophilic (water-attracting) heads facing outward toward the water-based environment while the opposite layer has hydrophobic (water-repelling) tails facing inward, away from water.
b. Proteins:
→ are embedded in the double phospholid layer and play a role in the cell structure and communication.
Describe the progression of microscopy technologies and discuss how these advancements have enhanced our knowledge of cell structure and function. (4 marks)
--- 5 WORK AREA LINES (style=lined) ---
→ The progression of microscopy technologies has revolutionised our understanding of cell structure and function.
→ Early light microscopes allowed scientists to observe basic cell components, such as the nucleus, but were limited in resolution.
→ The invention of the transmission electron microscope brought a major leap, enabling the detailed 2-D visualisation of organelles like mitochondria and the endoplasmic reticulum.
→ The development of the scanning electron microscope created high resolution 3-D images of cells. This allowed for the study of bacteria and cell-surface structures such as cilia.
→ More recently, confocal and fluorescence microscopy have allowed researchers to study living cells in real-time, providing dynamic insights into cellular processes.
→ These advancements have deepened our knowledge of cell biology, revealing intricate structures and functions previously unseen.
→ The progression of microscopy technologies has revolutionised our understanding of cell structure and function.
→ Early light microscopes allowed scientists to observe basic cell components, such as the nucleus, but were limited in resolution.
→ The invention of the transmission electron microscope brought a major leap, enabling the detailed 2-D visualisation of organelles like mitochondria and the endoplasmic reticulum.
→ The development of the scanning electron microscope created high resolution 3-D images of cells. This allowed for the study of bacteria and cell-surface structures such as cilia.
→ More recently, confocal and fluorescence microscopy have allowed researchers to study living cells in real-time, providing dynamic insights into cellular processes.
→ These advancements have deepened our knowledge of cell biology, revealing intricate structures and functions previously unseen.
Describe how the development of electron microscopy has improved our understanding of cell structure and function.
In your answer, compare the capabilities of transmission electron microscopes (TEM) and scanning electron microscopes (SEM), and give examples of how each is used in biological research. (4 marks)
--- 8 WORK AREA LINES (style=lined) ---
→ The development of electron microscopy has significantly enhanced our understanding of cell structure and function by providing much higher resolution images than light microscopes.
→ Transmission electron microscopes (TEM) allow scientists to view internal structures of cells in great detail by transmitting electrons through thin slices of specimens, revealing organelles like the mitochondria and endoplasmic reticulum.
→ In contrast, scanning electron microscopes (SEM) produce three-dimensional images by scanning the surface of a specimen with electrons, which is useful for studying cell surfaces and structures such as cilia or bacterial shapes.
→ Both TEM and SEM have been pivotal in biological research, allowing the discovery of cellular organelles and understanding of cell interactions at the microscopic level.
→ The development of electron microscopy has significantly enhanced our understanding of cell structure and function by providing much higher resolution images than light microscopes.
→ Transmission electron microscopes (TEM) allow scientists to view internal structures of cells in great detail by transmitting electrons through thin slices of specimens, revealing organelles like the mitochondria and endoplasmic reticulum.
→ In contrast, scanning electron microscopes (SEM) produce three-dimensional images by scanning the surface of a specimen with electrons, which is useful for studying cell surfaces and structures such as cilia or bacterial shapes.
→ Both TEM and SEM have been pivotal in biological research, allowing the discovery of cellular organelles and understanding of cell interactions at the microscopic level.
Which of the following correctly explains why a scanning electron microscope is advantageous in studying living cells?
\(A\)
→ Scanning electron microscopes capture detailed three-dimensional images of living cells, allowing researchers to observe cellular processes in real time with high resolution.
→ Unlike electron microscopes, this technology can be used to study live cells without extensive sample preparation that might kill the cells.
\(\Rightarrow A\)
Which of the following technologies was pivotal in discovering the internal structure of organelles such as mitochondria and the endoplasmic reticulum?
\(B\)
→ The transmission electron microscope (TEM) allows for the visualisation of internal cell structures at high resolution by passing electrons through thin sections of a sample.
→ This technology was crucial in discovering detailed organelle structures like mitochondria and the endoplasmic reticulum, which are not visible with light microscopes.
\(\Rightarrow B\)
--- 5 WORK AREA LINES (style=lined) ---
--- 6 WORK AREA LINES (style=lined) ---
a. Answers could include any two of the following:
→ Nucleus – the nucleus contains the cell’s genetic material and regulates gene expression.
→ Mitochondria – generates ATP through cellular respiration, providing energy for the cell’s functions.
→ Endoplasmic reticulum (ER) – helps synthesise proteins (rough ER) and lipids (smooth ER), contributing to various cell processes.
b. → Specialised organelles allow eukaryotic cells to compartmentalise tasks.
→ This increases metabolic efficiency and enables complex processes to occur within the cell.
→ In contrast, prokaryotic cells, lacking organelles, must perform all functions in the cytoplasm, limiting their ability to handle as many simultaneous or specialised activities as eukaryotic cells.
a. Answers could include any two of the following:
→ Nucleus – the nucleus contains the cell’s genetic material and regulates gene expression.
→ Mitochondria – generates ATP through cellular respiration, providing energy for the cell’s functions.
→ Endoplasmic reticulum (ER) – helps synthesise proteins (rough ER) and lipids (smooth ER), contributing to various cell processes.
b. → Specialised organelles allow eukaryotic cells to compartmentalise tasks.
→ This increases metabolic efficiency and enables complex processes to occur within the cell.
→ In contrast, prokaryotic cells, lacking organelles, must perform all functions in the cytoplasm, limiting their ability to handle as many simultaneous or specialised activities as eukaryotic cells.
--- 5 WORK AREA LINES (style=lined) ---
--- 5 WORK AREA LINES (style=lined) ---
a. Structural and functional differences:
→ Prokaryotic cells lack membrane-bound organelles and a true nucleus, with their DNA free-floating in the cytoplasm.
→ Eukaryotic cells, on the other hand, have a membrane-bound nucleus and various organelles such as mitochondria, which allow compartmentalisation of functions.
→ This structural difference enables eukaryotes to perform more complex processes, while prokaryotes are limited to simpler metabolic activities.
b. → Eukarytic organisms can manage multiple, specialised functions simultaneously.
→ This supports greater complexity in multicellular organisms and leads to highly organised systems with differentiated tissues and organs.
→ Prokaryotic organisms remain unicellular or simple multicellular forms, with all functions occurring in the same space.
a. Structural and functional differences:
→ Prokaryotic cells lack membrane-bound organelles and a true nucleus, with their DNA free-floating in the cytoplasm.
→ Eukaryotic cells, on the other hand, have a membrane-bound nucleus and various organelles such as mitochondria, which allow compartmentalisation of functions.
→ This structural difference enables eukaryotes to perform more complex processes, while prokaryotes are limited to simpler metabolic activities.
b. → Eukarytic organisms can manage multiple, specialised functions simultaneously.
→ This supports greater complexity in multicellular organisms and leads to highly organised systems with differentiated tissues and organs.
→ Prokaryotic organisms remain unicellular or simple multicellular forms, with all functions occurring in the same space.
Which of the following accurately explains why prokaryotic cells are generally smaller than eukaryotic cells?
\(B\)
→ Prokaryotic cells lack membrane-bound organelles, which limits their ability to compartmentalize functions.
→ This results in lower metabolic efficiency, constraining their size compared to eukaryotic cells.
\(\Rightarrow B\)
Which of the following structures is present in both prokaryotic and eukaryotic cells?
\(C\)
→ Both prokaryotic and eukaryotic cells contain ribosomes, which are responsible for protein synthesis.
→ Prokaryotes lack membrane-bound organelles like mitochondria or the Golgi apparatus.
\(C\)
Which of the following is a key structural difference between prokaryotic and eukaryotic cells?
\(B\)
→ Prokaryotic cells lack a membrane-bound nucleus, whereas eukaryotic cells have a well-defined nucleus that encloses their DNA.
\(\Rightarrow B\)