All sources of pollution come from human activities.

When a plant seed first starts to grow, what would happen if the cells did not differnciate?

When the Linnaean system of classification was first developed in the early 1700s, it only had two kingdoms for living things, the plant and animal kingdoms.

Plant and animal cells are different because * Plant cells do not have a nucleus or mitochondria Animal cells do not have DNA or ribosomes Plant cells do not have a cell membrane Animal cells do not have a cell wall or chloroplasts

The first trees evolved around 370 mya along a lakeshore at the foot of the caledonian range. how did these trees have a positive impact on plants and animals?

What is the period of cell life when it is conducting cell division?

For some reason (not yet understood) more male babies are conceived (born) than female. By childhood the number of boys and girls is the same. what is the possible explanation for the higher mortality (both before and after birth) of male babies?

A child's pituitary gland does not release enough hormones. What is the most likely cause of this? A. The child has no ovaries. B. The child has no adrenal hormones. C. The child's blood glucose level is too high. D.

Which tissue is correctly paired with its primary cell type? which tissue is correctly paired with its primary cell type? bone; osteoblast connective tissue proper; chondroblast cartilage; fibroblast bone; fibrocyte?

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Roentgens are used to measure the amount of: A) uranium, B) fuel burned, C) radiation, D) hydrogen isotopes