Need to review Flashcards
What is surface salinity?
The total amount of salt dissolved in seawater .
Relatively constant.
What are the properties of light in saltwater?
Relatively transparent.
Important for photosynthesis.
What are the properties of light in the open ocean?
Very transparent as there are fewer photosynthesizers.
What are the properties of light in coastal areas?
Less transparent
More abiotic and biotic organisms
What color is absorbed first in the water?
Red
Why is the ocean blue?
Because the color blue is absorbed last
What is very turbid water?
Cloudy with sediments.
The water absorbs blue wavelengths quicker to make water appear yellow-green. All light does not penetrate very deep.
What is moderately turbid coastal water?
Clear except for plankton so it appears greenish
What is clear water?
Has little to no plankton or sediment. Essentially equivalent to pure water.
Will be blue with light that penetrates the deepest.
What are tides?
The rising and falling of Earth’s ocean surface
What are tides caused by?
Complex interactions between gravitational and rotation forces acting on Earth’s moon-sun system.
What is the intertidal zone?
A strip of seashore that is submerged at the high tide and exposed at low tide.
What are spring tides?
The largest difference between the highest high tide and the lowest low tide (new moon and full moon)
What is a neap tide?
The smallest range between the highest high tide and the lowest tide (1st and 3rd quarter moon)
What is the tidal range?
Tides usually have a cycle of 2 lows and two highs per day.
What are semi-diurnal tides?
2 high and 2 lows of roughly equal magnitude.
Found on the East coast of N. America, Europe, and Africa.
What are mixed semi-diurnal tides?
A high high tide, 1 low low tide, 1 smaller high tide, 1 smaller low tide.
Found on the west coast of Canada and the US.
What are diurnal tides?
one high and one low tide per day
Uncommon
What is some evidence that early life began in the ocean?
Stromatolites
Hydrothermal vents
Cyanobacteria
Why does the size of an organism matter?
Because organisms need to be able to exchange water, nutrients, waste products, and gases with the marine environment.
More surface area = the greater the exchange of materials across the surface of the organism
Surface area / Volume (SA/V) is higher with smaller organisms.
What are some theories that bacteria density is constant on the surface of the ocean
- Sinking: bacteria attach onto organic material from other organisms and sinks into the sediment
- Predation
- Infection by marine viruses
Why is nitrogen fixation important?
Essential for growth for diatoms
What are the steps of endosymbiosis
1: Prokaryotic ancestor was engulfed by another prokaryote which became a mitochondrion (organelle used in respiration)
2. A eukaryotic ancestor engulfed a photosynthetic prokaryote (cyanobacterium), which became a chloroplast.
What is secondary endosymbiosis?
Lost their original chloroplast and then acquired a new type by engulfing a photosynthetic eukaryote
What is tertiary endosymbiosis?
the eukaryotic host engulfed other photosynthetic eukaryotes at least two separate times.
Describe plastid evolution
Prokaryote engulfs prokaryote
Eukaryote engulfs prokaryote
Eukaryote engulfs eukaryote.
How does asexual reproduction work in diatoms?
Frustules separate & each forms a new ‘smaller’ diatom.
One cell is the original size and one is smaller
Eventually, diatoms become too small to divide asexually; @ about 25% or orig. size.
During ASEXUAL reproduction, diatom cells only make NEW hypothecas
How does sexual reproduction work in diatoms?
Fertilized small diatoms shed frustules & produce a ‘naked’ cell, called an auxospore.
Auxospores enlarge to the original cell size and form a new frustule.
When nutrients and light are replete, an asexual cycle is initiated
How do dinoflagellates reproduce?
Binary fission (asexual): Theca splits & each half forms a new dinoflagellate of the same size Sexual reproduction: Planozygote–Fused ‘male’ and ‘female’ Resting cyst–facilitates survival through harsh environmental conditions and amerging dinoflagellate from the cyst.
