BIOL Exam 2

Prokaryotes have nuclei but no mitochondria or chloroplasts.

false

Though diffusion results in a net movement of a substance from an area of high to an area of low concentration, it is based completely on random molecular motions.

true

Sperm and eggs generally have a haploid number of chromosomes.

true

Most marine fishes have body fluids more dilute than seawater and thus must drink seawater to replace osmotically lost water.

true

Natural selection occurs when there are heritable differences among members of a population that lead some members to reproduce more successfully than others.

true

The ecosystem best encompasses which one of the following?

The community or communities and the physical environment

Typical marine fishes

tend to lose water by osmosis since their internal salt concentration is lower than that of seawater.

A group of mussels of a particular type living together on a rocky beach is an example of a(an)

population

Which of the following correctly links the type of organisms with the way they live?

Organisms part of the nekton swim

Marine organisms whose internal salt concentration varies with that of their environment are examples of

osmoconformers.

Why aren't cells larger?

Surface area to volume ratio

It is impossible for an animal to be a poikilothermic endotherm

false

Stromatolites are calcareous mounds formed by colonies of cyanobacteria.

true

Diatoms have a protective covering made out of cellulose.

false

Asexual reproduction in diatoms usually results in

One larger and one smaller cell.

Dinoflagellates move using two flagella, one wrapped around a central groove, and one trailing free.

true

Dinoflagellates are often responsible for toxic red tides and for the diffuse bioluminescence of the open sea.

true

Foraminiferans and radiolarians feed by

using a network of pseudopodia to trap food.

Dinoflagellates that live in association with reef-building corals and other animals are known as

zooxanthellae

Responsible for paralytic shellfish poisoning.

saxitoxin

An organism responsible for bioluminescence.

dinoflagellate

Deadly poision found in pufferfish and blue ring octopus:

tetrodotoxin

In a diatom, the epitheca fits into the hypotheca.

false

Has a vase-like test made of sand:

tintinnid

In some seaweeds, leaf-like portions called blades are kept near the sea surface with gas-filled bladders called pneumatocysts.

true

The Chlorophyta includes the largest algae, the giant kelps.

false

Cordgrasses of salt marshes

Can excrete excess salt.

Sea grasses grow in clusters interconnected with horizontal root-like stems.

true

Salt marsh plants such as cordgrass are fully marine species.

false

Pigment found in Phaeophyta

fucoxanthin

The stem-like structure of seaweeds, such as kelp, is called the

stipe

The root-like, anchoring structure of many seaweeds is called the

holdfast

Part of the holdfast:

haptera

Cordgrass (spartina sp.) are:

emergent

Which is not a special adaptation for planktonic existence?

roots

Salt-tolerant plants such as salt-marsh plants are called

halophytes

Autotrophs

Self feeders via photosynthesis and chemothesis. Primary Producers.

Heterotrophs

Eat organic matter, secondary producers.

Plankton

Drifting organisms

Nekton

Organisms that swim against the current

Benthic

Bottom of the sea organism

Diffusion

How gasses enter cells, high to low concentration of molecules until equilibrium, random motion of molecules

Osmosis

Movement of water across membrane, moves from areas with less solute to more solute (low to high movement)

Passive Transportation

No energy, diffusion

Active Transport

Requires energy, osmosis

Osmoconformer

Internal concentrations change to water, stay in favorable environment

Osmoregulator

Control internal environment

Saltwater Fish

Water loss by osmosis, drinks water, excrete salt from gills, small volume of salty urine

Freshwater Fish

Water gain by osmosis, does not drink water, salt absorbed by gills, large volume of dilute urine

Poikilotherm

Coldblooded, body temp varies with ambient temperature, cannot regulate

Ectotherm

Regulates body temperature by exchanging heat with environment

Homeotherm

Warmblooded, body temperature constant, independent of ambient temperature

Endotherm

Generates heat to maintain its body temp, usually higher than ambient temperature

Asexual Reproduction

Cell fission, daughter cells are typically smaller

Sexual Reproduction

Union of gametes, genetic recombination

Heterotrophic Prokaryotes

Decomposers, slower at depth

Autotrophic Prokaryotes

Photosynthetic, chemosynthetic

Chlorophyll

Green pigment

Phycocyanin

Blue pigment

Phycoerythrin

Red pigment

Benthic Cyanobacteria

Microscopic colonies

Stromatolites

Calcareous mound built up over time, associated with coral reefs

Epiphytes

Attached to other plants

Endophytes

Lives inside algae

Endolithic

Burrow in calcareous rock/coral

Mutualistic

Association between organisms of two different species in which each benefits

Parasitism

One organism is beatified at the expense of another

Commensalism

Epiphytes, one species obtains food in which one species obtains food or other benefits from the other without either harming or benefiting the latter

Diatoms

Often most abundant and phytoplankton, frustule shell

Dinoflagellates

Two flagella, photosynthetic pigments, articulated cell walls

Zooxanthellae

Symbiotic dinoflagellate that supplies coral with nutrients, plays a part in red tides

Phylum Chrysophyta (Silicoflagellates)

Star-shaped silica

Phylum Haptophyta (Coccolithophorids)

Small calcareous plates = coccoliths warm and temperate seas

Phylum Cryptophyta (Cryptomonads)

2 flagella, no skeleton

Phylum Foraminifera (forams)

Several chambers, Pores, Pseudopodia extend thru to catch food

Phylum Polycystina (Radiolarians)

Silica shell, pseudopodia

Phylum Ciliophora (Ciliates)

Cilia, Paramecium (FW), Tintinnids, Vase-like test made of sand, drift

Fungi

Eukaryotic, Multicellular (most), Decomposers, Parasites, Supports algae

Bloom

A sudden and dramatic increase in the phytoplankton population over a restricted geographic region, increase of nutrients and light cause this event

Chlorophyta (Green algae)

Simple filaments, Flat sheets, Branching

Coraline Green Algae

Some epiphytes & endophytes

Phaeophyta (Brown algae)

Fucoxanthin over chorophyll, Kelp: West coast of US, Sea bottom hard and stable

Rhodophyta (Red algae)

Phycobilins over chorophyll

Coralline Red Algae

Calcareous, Encrusting

Blade

Cells on surface are more active in photosynthesis than deeper ones, Each surface similar in structure and function, Large kelp all look similar when young

Pneumatocysts

gas-filled floats, Sargassum, N2, O2, CO2, and CO

Stipe

May transport photosynthetic products down algae

Holdfast

Short rootlike haptera, DO NOT take up nutrients

Salt Marsh

Submergent seagrasses, horizontal rhizomes, pollen carried by water

Cordgrass

Emergent, salt tolerant, excretes from leaves, salt marsh

Halophytes

“Salt tolerant” found higher in the salt marsh

Mangrove Swamps

Tropical and subtropical, tree-like plants, salt tolerant but not cold tolerant (replaced by salt marsh). Red, Black, and White variations

Photocyte

“light cell”

Photophore

more complex form of light emitting cells surrounded by pigments, mirrors, and light shields

Scintillon

Small structures in cytoplasm that produce light

Reasons for bioluminescence

Mating, avoid predation, lure prey, general defense