The fourth week after conception, growth is rapid. the neutral tube along a baby’s back is closing and the baby’s heart is pumping blood. if this neutral tube does not close properly, a condition called may results.

In which state was more than 100 billion tons of coal mined in 2005?

How do you know that the plant cells in these two images have different jobs, or functions? a. because all plant cells serve different functions b. because they are two different colors c. because their dna are different d. because their structures are different

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?