Which of the following organelles does not have a cell membrane?

Name the energy currency of the cell. Which cell organelle releases this currency?

Name two double membraned cell organelles.

Lysosomes arise from:

$(a)$ Which major invention led to the discovery of the microscopic world?
$(b)$ Name a single cell which may constitute a whole organism. What are they called?
$(c)$ Every multicellular organism has come from a single cell. Justify the statement.

Functional segments of $DNA$ are called