In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

How does a chestnut tree form its heartwood?, Context: The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change comes slowly. Thin sapwood is characteristic of such species as chestnut, black locust, mulberry, osage-orange, and sassafras, while in maple, ash, hickory, hackberry, beech, and pine, thick sapwood is the rule. Others never form heartwood.
the change comes slowly

what has the better chloroplasts, Context: The alga Cyanophora, a glaucophyte, is thought to be one of the first organisms to contain a chloroplast. The glaucophyte chloroplast group is the smallest of the three primary chloroplast lineages, being found in only 13 species, and is thought to be the one that branched off the earliest. Glaucophytes have chloroplasts that retain a peptidoglycan wall between their double membranes, like their cyanobacterial parent. For this reason, glaucophyte chloroplasts are also known as muroplasts. Glaucophyte chloroplasts also contain concentric unstacked thylakoids, which surround a carboxysome - an icosahedral structure that glaucophyte chloroplasts and cyanobacteria keep their carbon fixation enzyme rubisco in. The starch that they synthesize collects outside the chloroplast. Like cyanobacteria, glaucophyte chloroplast thylakoids are studded with light collecting structures called phycobilisomes. For these reasons, glaucophyte chloroplasts are considered a primitive intermediate between cyanobacteria and the more evolved chloroplasts in red algae and plants.
red algae

What change was made to how the federal government approached selection of racial categories on forms?, Context: Multiracial people who wanted to acknowledge their full heritage won a victory of sorts in 1997, when the Office of Management and Budget (OMB) changed the federal regulation of racial categories to permit multiple responses. This resulted in a change to the 2000 United States Census, which allowed participants to select more than one of the six available categories, which were, in brief: "White," "Black or African American," "Asian," "American Indian or Alaskan Native," "Native Hawaiian or other Pacific Islander," and "Other." Further details are given in the article: Race (U.S. census). The OMB made its directive mandatory for all government forms by 2003.

permit multiple responses