Chloroplasts are cell organelles that are key in the process of photosynthesis.
The chloroplasts have two distinct parts, one of them called the thylakoid containing the chlorophyll, a pigment essential for photosynthesis and the stroma, a liquid part that contains DNA molecules, enzymes, and ribosomes.
The correct answer is B. Ordovician period
Explanation:
Plants are mainly multicellular organism that depends mainly on photosynthesis to obtain energy, this includes a wide variety of species such as grass, flowering plants, trees, shrubs, etc. Additionally, plants are considered as one f the two major divisions or kingdoms along with animals. In terms of history, it has been determined first land plants appear during the mid-Ordovician period around 470 million ago, although organisms that were the origin of land plants developed in water in previous periods, also by the Devonian period a wide variety of plants have emerged with features that are still part of plants nowadays. Therefore, plant life first appeared on land during the Ordovician period.
