Question

1. a long, narrow estuary with a u - shaped cross - section that was carved out by a retreating glacier is known as a:

a) bar - built estuary
b) coastal plain estuary
c) tectonic estuary
d) fjord

1. estuarine water is often murky because:

a) the water is naturally dark brown in color.
b) it contains a high concentration of suspended sediments from river runoff.
c) large amounts of phytoplankton block the sunlight.
d) the constant mixing with saltwater creates a cloudy effect.

1. salt marsh plants, known as halophytes, have a specific adaptation to deal with high salinity. which of the following is a common adaptation?

a) their leaves absorb excess water to dilute the salt.
b) they possess special glands on their leaves that excrete excess salt.
c) they have very thin, delicate cell walls that allow salt to pass through.
d) they grow only during low tide to avoid contact with saltwater.
27 the san francisco bay is an example of a tectonic estuary. how are these estuaries formed?
a) they are created by retreating glaciers.
b) they form when sandbars build up along the coast.
c) they are formed when the land subsides (sinks) due to movement of the earths crust.
d) they are simply drowned river valleys.

1. the amount of salt in an estuarys water changes with the tide. this means that animals living there must be able to handle changes in:

a) water clarity
b) water color
c) salinity
d) water temperature

1. in a typical estuary, the water is saltiest:

a) deep inside the river.
b) near the ocean.
c) in the middle of the estuary.
d) at the surface of the water.

1. an estuary is found where:

a) a desert meets a mountain.
b) a river meets the ocean.
c) two oceans meet.
d) a jungle meets a city.

Explanation:

1. Fjords are long, narrow estuaries with U - shaped cross - sections carved by glaciers.
2. Estuarine water is murky due to high suspended sediment from river runoff.
3. Halophytes have special leaf glands to excrete excess salt.
4. Tectonic estuaries form when land subsides due to crust movement.
5. Animals in estuaries must handle salinity changes as salt content varies with tides.
6. Water is saltiest near the ocean in an estuary as that's where seawater enters.
7. Estuaries are where a river meets the ocean.

Answer:

1. D. Fjord
2. B. It contains a high concentration of suspended sediments from river runoff.
3. B. They possess special glands on their leaves that excrete excess salt.
4. C. They are formed when the land subsides (sinks) due to movement of the Earth's crust.
5. C. Salinity
6. B. Near the ocean.
7. B. A river meets the ocean.