MICROANATOMY

Detailed explanation-1: -Mitochondria are surrounded by a double-membrane system, consisting of inner and outer mitochondrial membranes separated by an intermembrane space (Figure 10.1). The inner membrane forms numerous folds (cristae), which extend into the interior (or matrix) of the organelle.

Detailed explanation-2: -The double membrane found in mitochondria and chloroplasts appears to be a relic of the absorption of the prokaryotic bacteria by the eukaryotic host cells. The inner membrane, which now contains numerous folds, apparently came from the bacterial membrane, while the outer membrane came from the host cell itself.

Detailed explanation-3: -Like mitochondria, chloroplasts are surrounded by two membranes. The outer membrane is permeable to small organic molecules, whereas the inner membrane is less permeable and studded with transport proteins.

Detailed explanation-4: -Answer and Explanation: Both the nucleus and the mitochondrion are surrounded by two layers of unit membrane. Other double membrane-bound organelles include the Golgi body, endoplasmic reticulum and chloroplasts in plant cells.