ACTIVITY 2 THE PROKARYOTES

Haplontic

___________ sexual life cycle is characterized by zygotic meiosis wherein the diploid zygote undergoes meiotic division resulting in four haploid daughter cells.

Diplontic

______________ type of sexual life cycle is characterized by gametic meiosis wherein meiotic division results in the formation of haploid gametes that fuse to form the diploid zygote.

Diplohaplontic

_______________ type of sexual life cycle is characterized by sporic meiosis (wherein meiotic division leads to the formation of haploid spores) as well as alternation of haploid and diploid adult forms.

euglenoids

The _____________ of Division Euglenophyta are photosynthetic and heterotrophic flagellates.

euglenoids

They are motile unicellular protists equipped with a thread-like locomotory structure called a flagellum and lack cell walls.

euglenoids

They occur in most freshwater habitats including puddles, ditches, ponds, streams, rivers, and lakes.

gullet (cytostome)

One of the most common genera of euglenoids is Euglena. These are slipper-shaped organisms.

The anterior end is invaginated to form a flask-shaped structure, the ______________, from which two flagella arise.

reservoir

One of the most common genera of euglenoids is Euglena. These are slipper-shaped organisms.

The flagella originate from the base of the bulb-shaped ____________ (the lower portion of the gullet).

eyespot or stigma

One of the most common genera of euglenoids is Euglena. These are slipper-shaped organisms.

The orange-pigmented _______ or ________ can be found in the gullet. It allows the organism to sense the direction of light.

paramylum bodies

One of the most common genera of euglenoids is Euglena. These are slipper-shaped organisms.

Suspended in the cytoplasm are several green discrete bodies, the chloroplasts containing chlorophyll a and chlorophyll b. Euglena stores reserved food material in the form of paramylon found in light-colored _________________ scattered in the cytoplasm.

pellicle

One of the most common genera of euglenoids is Euglena. These are slipper-shaped organisms.

The outer part of the cell is covered by a thin, firm, pliable membrane called the _________ instead of cell wall.

longitudinal fission

Reproduction in Euglena is usually by ______________ but is not often observed. The cell begins to divide at the anterior end with one half keeping the flagellum and the other half growing a new one. Nuclear division occurs before the cell begins to split into two parts.

euglenoid movement or metaboly

Live Euglena are green, with motile cells that constantly change shape. The characteristic movement that you have observed is called _________________ or ____________.

alveolates; alveoli

macronucleus; micronucleus

The ciliates, apicomplexans and dinoflagellates comprise the clade called _____________. This clade is characterized by the presence of _________, which are small membrane bounded cavities beneath cell surfaces.

Another distinctive feature of the ciliates is the presence of two types of nuclei: the _____________ and _____________.

oral groove; cytostome; gullet or cytopharynx

On the flattened side of the paramecium is a diagonally directed ___________ which opens into the mouth or ___________, which in turn leads into the ________ or _________.

radiating; canals; food vacuoles

In the cytoplasm of the paramecium, two contractile vacuoles may be found (one near the posterior end and the other just anterior to the middle portion of the cell). When it contracts and disappears, the _________ (vacuolar) __________ become discernible.

The ______________ are small spherical bodies scattered throughout the cytoplasm. These structures are responsible for digesting food particles.

macronucleus; micronuclei

Near the anterior contractile vacuole of the paramecium, the large, clear, oval _____________ (which serves as the center of metabolic activities of the organism) can be seen. Close by are the _____________ (responsible for reproductive processes) which usually vary among species, but none are easily discerned.

transverse fission; conjugation

Reproduction in Paramecium is accomplished asexually by ______________ and exchange of genetic material is possible by _____________.

Stramenopiles

The main characteristic of _____________ is the presence of fine, hair-like projections on the flagella. Most often, the hairy flagellum is paired with a non-hairy flagellum.

To this group belong the oomycetes and heterokont algae.

Oomycetes

Stramenopiles

_____________ are heterotrophic and include water molds, downy mildews, and white rusts. Most water molds are decomposers, while white rusts and downy mildews are plant parasites.

Oomycetes; hyphae

Stramenopiles

____________’s cell walls are typically made up of cellulose. Some are unicellular while others consist of fine, branching filaments called __________.

heterokont

Stramenopiles

The ____________ algae include the golden algae (Division Chrysophyta), diatoms (Division Bacillariophyta), and brown algae (Division Phaeophyta).

Diatoms

____________ are essentially unicellular golden-brown photosynthetic organisms but may form chains and colonial aggregates. They are very widespread in nature, occurring in aquatic (freshwater, marine and brackish) and terrestrial and subaerial habitats.

Diatoms; carotene; xanthophylls; fucoxanthin

They are commonly called the grass of the sea. The __________ cell has a central vacuole and one, two, or many golden-brown chloroplasts. The photosynthetic pigments include chlorophylls a and c together with _________ and ____________, including ____________.

Diatoms

Food is stored as oils and chrysolaminarin. The cells are uninucleate, diploid and have gametic meiosis. Reproductive cells of the diatoms are motile, having a single anterior two-sided tinsel flagellum.

diplontic

Diatoms reproduce both asexually and sexually. Similar to the members of the animal kingdom, its sexual life cycle is __________.

The diploid zygote, in the case of diatoms, grows into a large cell and then becomes dormant before germination. When a diatom germinates, it undergoes a round of nuclear and cell division where each daughter cell receives one of the valves from the mother cell.

pennate; centric

Navicula under the microscope appears as golden-brown, unicellular, boat-shaped bodies. Diatoms may have bilateral symmetry (__________ diatoms) or radial symmetry (_________ diatoms).

Diatoms; pectin; silica; frustules; epitheca; hypotheca

A distinct feature for _________ is the cell wall, made up of _________ and impregnated with large amounts of ___________. This silicified cell wall consists of two overlapping parts that fit together like halves of petri dish. The two halves are called ____________, the outer one is the __________ and the inner one or the bottom half is the __________.

valve; girdle; valve view; girdle view

Each half of the diatom’s silicified cell wall consists of a main surface, the ________, and the overlapping connecting bands. The two connecting bands constitute the _______. When viewed from above or below, the diatom is seen in ____________. When viewed from the side, it is the ____________.

striae; raphe; polar nodules

On the diatoms, complex markings or ________ are found on the valve of the cell wall, arranged parallel to each other but perpendicular to the cell axis. In the center of the valve of most pennate diatoms is a groove called _______, which may be straight, wavy, or S-shaped. At the ends of the raphe are _____________.

Sargassum, a brown alga (Division Phaeophyta)

The brown algae, all representatives being multicellular, are the largest and vegetatively the most complex of the algae. They range from microscopic filamentous forms to macroscopic seaweeds, giant kelps reaching heights of about 50 meters. There are no motile brown algae but they do produce motile reproductive cells. Brown algae are primarily marine organisms occurring on rocky coasts and cold ocean waters.

alginic acid

Cell walls of Sargassum, brown algae have inner cellulosic layer and an outer mucilaginous layer of pectin and large amounts of _________. The cellulose of brown algae differs from that in green plants because it consists of both glucose and xylulose units.

laminarin; mannitol

In Sargassum, brown algae, the storage food material accumulates outside the chloroplasts as __________ (a polysaccharide), ___________ (a sugar alcohol) and lipid droplets.

Sargassum

__________ is a very conspicuous brown alga in tropical and subtropical waters and includes some of the most specialized of the algae. Some species grow attached to the bottom of the oceans while some are floating.

fucoxanthin

Sargassum, brown algae is photosynthetic, but it is brown. The brown color is due to the abundance of xanthophyll pigment, ___________, which is dominant over chlorophyll a and c, carotene and other xanthophylls.

holdfast; blade; air bladders; stipes

Sargassum, brown algae, has a _____________ which functions in anchoring the attached forms. From cylindrical main axes arise flattened, sterile, leaf-like laterals, called the ________. In the axes of these blades are spherical ____________. The stalks holding the blades are called __________.

Thallus

In Sargassum, brown algae, __________ (plural thalli) is the proper term used for tissue-forming body of such organism lacking the complex organs of the vascular plants. Algae with this type of body are described as thalloid.