Down syndrome is the result of an extra chromosome 21 in a gamete. What caused this to happen?

nondisjunction

telomeres

environment

chromosome inactivation

Which process always involves the movement of materials from inside the cell to outside the cell? A) phagocytosis B) exocytosis C) endocytosis D) osmosis

Why is dark skin (a result of increased melanin production in equatorial peoples) likely a response to ultraviolet (uv) radiation?

The table below shows carbon dioxide emissions and world population data for several years between 1800 and 2004. Year World Population (billions) Carbon Dioxide Emissions (metric tons carbon per year) 1800 1 100 1850 1.3 175 1900 1.7 500 1950 2.

Which of the following statements is true? Good physical health requires at least 30 minutes of aerobic exercise each day. Snuff does not contain actual tobacco, but it is considered a form of tobacco use.

The specific heat capacity of water is 4.18 J / (g*^ C), while the specific heat of iron is 0.46 J / (g=^ C).

What is dioxyribonucleic acid?

Which list contains only bones that form part of the orbit of the eye?

Which of the following would be an example of species diversity? the number of different kinds of plants in an ecosystem the number of different kinds of animals living in all ecosystems the number of different kinds of plants and animals in an

Which of these was not characterized of the first cells on Earth? A. anerobic B. prokaryotic C. single-celled D. contained organelles

Where would you expect to find green algae? Choose three answers. A. in the shadow of a cactus B. between the grasses in a marshy pond C. in a dark hollow in a rainforest D. in a shallow ocean lagoon