Questions

Yes, plant cells have Mitochondria.

While plant cells have chloroplasts to photosynthesize, they also require ATP for cellular functions, and do use oxygen to break down some of the sugar they produce in order to generate that ATP. They need mitochondria for this.

In particular, at night when there is no light, plants undergo cellular respiration since there is no sunlight to photosynthesize.

They do, however, produce far more sugar and oxygen through photosynthesis than they use up in respiration.

The marrow cavity is also known as the medullary cavity. It is the central cavity of bone shafts where adipose tissue is stored. It is lined with a thin, vascular membrane called endosteum.

A command economy types of government decide which goods would be produced without any interference of the public.

Command economy ran in Germany during the rule of Adolf Hitler. 

A command economy tends to exist under a socialist government that provides a lot of regulation.

A locked file can be accessed by only one user.

A cold or flu illness.