Eukaryotic Cell Structure

Question 1

Nucleus

Answer 1

• DNA directs protein synthesis and controls metabolic activity
• Double membrane (nuclear envelope)
• Nuclear pores
• DNA could around his tones, forming chromatins (condense to make chromosomes)
• Nucleolus made of RNA and proteins, in charge of ribosome production

Question 2

Mitochondria

Answer 2

• Produce ATP
• Have a double membrane
• Inner membrane highly folded into cristae
• Fluid interior called the matrix
• Contain DNA and ribosomes

Question 3

Lysosomes

Answer 3

• Specialised vesicles containing hydrolytic enzymes
• Responsible for breaking down waste materials
• Aid in apoptosis and programmed cell death

Question 4

Cytoskeleton

Answer 4

• Microfilaments: Contractile fibres formes from actin. Responsible for cell movement and cell contraction during cytokinesis.
• Microtubules: Globular Tubulidentata proteins polymerise to form tubes that are used to form a scaffold-like structure. Determine the shape of a cell, while acting as a track for the movement of organelles.
• Intermediate fibres: provide mechanical strength to cells, maintaining cell integrity.

Question 5

Centrioles

Answer 5

• Composed of micro tubules, acting in pairs to form a centrosomes during cell division
• Flagella: Provide movement and can act as sensory organelles to detect environmental changes.
• Cilia: Stationary cilia play an important role in sensory organs. Mobile cilia beat in a rhythm, moving fluids and solids, such as in the trachea.
• The microtubules in cilia are arranged in a ‘9+2’ formation

Question 6

Cellulose cell wall

Answer 6

• Rigid cellulose wall, but still are freely permeable
• Contents of the cell press against the cell wall making it rigid, providing support for the individual cell but also the entire plant

Question 7

Vacuole

Answer 7

• Membrane lined fluid sacs in the plant cell cytoplasm
• Contains cell sap that provides turtle to the cell, maintaining shape
• The membrane (tonoplast) is selectively permeable