Cell Nucleus Structure Quiz

Cell Structure and Functions

• The nucleus is separated from the cytoplasm by a porous nuclear membrane that allows the movement of materials between the two.
• The nucleus contains thread-like structures called chromosomes, which carry genes and help in inheritance or transfer of characters from parents to offspring.
• Chromosomes can only be seen when the cell divides.
• The nucleus acts as the control center of the activities of the cell.

Nucleolus and Protoplasm

• A smaller spherical body in the nucleus is called the nucleolus.
• The entire content of a living cell is known as protoplasm, which includes the cytoplasm and the nucleus.
• Protoplasm is called the living substance of the cell.

Cellular Differences

• The nucleus of bacterial cells is not well-organized like the cells of multicellular organisms.
• Bacterial cells lack a nuclear membrane and are termed prokaryotic cells.
• Examples of prokaryotes include bacteria and blue-green algae.

Cell Components

• Cytoplasm is a jelly-like substance present between the cell membrane and the nucleus.
• Various organelles, such as mitochondria, golgi bodies, and ribosomes, are present in the cytoplasm.
• The cell membrane is a thin layer that separates the cell from its environment.
• Cell walls are present in plant cells but absent in animal cells.

Genes and Inheritance

• A gene is a unit of inheritance in living organisms that controls the transfer of a hereditary characteristic from parents to offspring.
• Genes result in different characteristics due to the combination of genes from parents.

Comparison of Plant and Animal Cells

• Plant cells have a cell wall, whereas animal cells do not.
• Plant cells have plastids, whereas animal cells do not.
• Both plant and animal cells have a cell membrane, nucleus, and cytoplasm.

Key Terms

• Eukaryotes: cells with a well-organized nucleus.
• Multicellular: organisms composed of multiple cells.
• Organelles: smaller components present in the cytoplasm.
• Prokaryotes: cells without a well-organized nucleus.
• Tissue: a group of similar cells that perform a specific function.