OBJECTIVE FORESTRY

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: -Final answer: Organelles that are surrounded by two membranes are Nucleus and mitochondria.

Detailed explanation-3: -Besides the nucleus, two other organelles-the mitochondrion and the chloroplast-play an especially important role in eukaryotic cells. These specialized structures are enclosed by double membranes, and they are believed to have originated back when all living things on Earth were single-celled organisms.

Detailed explanation-4: -One of the main functions of the two membranes of a mitochondrion is to create the inter-membrane space between them. The inner membrane allows hydrogen ions to pass through it and into the inter-membrane space. However, the outer mitochondrial membrane does not allow the hydrogen ions to leave.