-
a. Chlorophyta (Green Algae)
i. Diverse in __; most are __, but many are found in several habitats
1. A diverse population of __, __, __green algae occurs in desert microbiotic crusts worldwide
a. In addition to green algae, such __comprise communities of cyanobacteria, diatoms, lichens, etc. bound to the __
i. These __ evolved from freshwater __ multiple times
- structure and life history
- aquatic
- microscopic, unicellular, free-living
- crusts
- upper layer of soil
- desert algae
- green algae
-
i. Some green algae (like __ and __) produce large amounts of __that function as a __, which give the algae an __(3)__ color
ii. Most aquatic green algae are found in __, but a couple are marine species.
- chlamydomonas and chloromonas
- carotenoids
- shield against intense light
- orange, red, or rust
- freshwater
-
i. Resemble __ and __
1. They are the only groups of organisms that contain __ and __ and store __, their food reserve, inside __
2. Some, but not all, green algae are like __ and __ plants in having firm __ composed of __, __, and __substances
- bryophytes and vascular plants
- chlorophylls a and b and store starch,
- plastids
- bryophytes and vascular
- cell walls
- cellulose, hemicelluloses, and pectin
-
a. In addition, the microscopic structure of the __ in some green algae resembles that of plant sperm cells
i. These features, in conjunction with molecular data, strongly indicate that green algae and land plants (bryophytes and vascular plants) form a __ known as the __
- flagellated reproductive cells
- monophyletic group
- Viridiplantae
-
i. Classified according to __, although not always recognized by it
1. __, __, etc
ii. Use of __, and molecular similaritiesà new systematic alignment of the green algae into several classes
1. Three are __(3)__
- outer structure,
- Unicellular flagellates, Filamentous types
- mitosis, cytokinesis, and reproductive cells
- Chlorophyceae, Ulvophyceae, and Charophycaea
-
i. Differences in Cell Division and Motile Cells
1. Freshwater Chlorophyceae have a unique mode of __ involving a __
a. The daughter nuclei do what as what happens, and a new system of microtubules, the __, develops __to the plane of cell division
- cytokinesis
- phycoplast
- move toward one antoher
- nonpersistent mitotic spindle collapses
- phycoplast
- parallel
-
a. The role of the phycoplast is to __ i. The __ persists throughout mitosis
1. In motile cells of the __, there is a crisscrossed pattern of four narrow bands of microtubules called __
- ensure that he cleavage furrow will pass between two daughter nuclei
- nuclear envelope
- chlorophyceae
- flagellar roots
-
i. In other algae, __remain throughout __until disrupted by the __ or __
1. Some members of Charophyceae produce a new __, the __, which is nearly identical to that present in bryophytes and vascular plants
- spindles
- cytokinesis
- furrow or growth plate
- cytokietic microtubular system
- phragmoplast
-
a. The microtubules in a phragmoplast are oriented __to the plane of cell division
i. The phragmoplast serves as a“__” for formation of the __
b. Flagellated cells of the charophyceae have an __ of microtubules
- perpendicular
- scaffolding
- cell plate
- asymmetrical flagellar root system
-
i. Role of the flagellar root system is to __
ii. Sometimes, an associated multilayered structure is associated with one of the __
b. The __ of the __is similar to that found in the sperm of bryophytes and vascular plants
- provide anchorage
- flagellar roots
- flagellar root system
- charophyceae
-
i. Class Chlorophyceae
1. Includes __ and __, __ and __ algae, __, and algae with __
2. Most are __; __is marine; and, some are __
- flagellated and nonflagellated unicellular algae,
- motile and nonmotile colonial
- filamentous
- flat sheets fo cells
- freshwater
- plankton
- terrestrial
-
1. Motile Uncellular Chlorophyte: Chlamydomonas
a. Two equal __
b. __group; it consists of several distinct lineages
c. Its chloroplast, in having a __, or __, does what and is similar to what?
- flagella
- Polyphylectic
- red photosensitive eyespot,
- stigma
- aids in the detection of light and is simiiar to flagellates of zoospores
-
i. The chloroplast also have a __, suppounded by a shell of __
1. Similar __occur in many other green algal species
2. The __ is surrounded by a thin __, inside which is the cell membrane
b. There is no cellulose in the cell wall
i. At the end of the cell are two __, which collect excess water and ultimately discharge it from the cell
- pyrenoid
- starch
- pyrenoids
- uninucleate protoplast
- glycoproteinaceous cell wall
- contractile vacuoles
-
a. Sexual reproduction in Chlamydomonas involes __ in different mating types
i. __ are induced to form __by __
1. The gametes, which resemble the __, first become __
a. Within these clumps, __are formed that stick together, first by their __ and later by a slender __—the __—that connects them at the base of their flagella
- fusion of individuals
- Vegetative cells
- gametes
- nitrogen fixation
- vegetative cells
- aggregated in clumps
- pairs
- flagellar membranes
- protoplasmic thread
- conjugation tube
-
i. As soon as this protoplasmic connection is formed, the __becomes free, and one or both pairs of flagella propel the partially fused gametes through the water
ii. The __of the two gametes fuse completely (__), followed by fusion of their nuclei (__), forming the zygote
- flagella
- protoplasts
- plasmogamy
- karyogamy
-
i. The four flagella __ and __ and a __ forms around the diploid zygoate
ii. This thick-walled zygote or zygospore then undergoes __
iii. __occurs at the end, producing __, which each develop two flagella and a cell wall; they can either divide __or produce a new __
2. __ is dominant, but they also exhibit __
- shorten and disappear
- thick cell wall
- dormancy
- Meiosis
- four haploid cells,
- asexually
- zygote
- Haploid phase
- zygotic meiosis
-
i. Motile Colonies of Chlorophyceae
1. __is an example (spheroid)
a. Single layer of 500-600,000 vegetative, biflagellated cells that do __, and some larger nonflagellated __cells, which undergo mitoses to form many-celled, __, which hatch from the parental spheroid by releasing an __that __
- Volvox
- photosynthesis
- reproductive
- juvenile spheroids
- enzyme
- dissolves the transparent parental matrix
-
i. As the spheroids first develop, all of the flagella __, so the colony must __ before __.
b. Sexual reproduction is always __; in all species so far, it is __, within the population of colonies by a __ that is produced by a spheroid that has itself become __by some other, as yet poorly understood mechanism
- face the hollow center
- turn inside out before it can become motile
- oogamous
- synchronous
- sexual inducer
- sexual
-
Nonmotile unicellular Chlorophycae
a. Ex: chlorococcum found in microbial flora of soils
i. There’s a huge number of __ that superficially resemble them but can be distinguished by __
1. Reproduce __by producing __, released from the parental cell
2. Sexual reproduction is accomplished by the __, which __ to form __
a. Meisosis is __
- genera of unicellular soil algae
- cellular, reproductive, and molecular features
- asexually
- biflagellated zoospores
- release fo flagellated gametes
- fuse in pairs
- zygotes
zygotic
-
i. Nonmotile Colonies
1. Include __, the water net
a. Under favorable conditions, it forms massive __ in ponds, lakes, and gentle streams
2. Each colony has __ in the form of a __
3. Initially __, each becomes __
a. At maturity, each cell contains a large __ and __containing the nuclei and a large __ with numerous pyrenoids
- hydrodictyon
- surface blooms
- large, cylindrical cells arranged
- lacy, hollow cylinder
- uninucleate
- multinucleate
- central vacuole and peripheral cytoplasm
- reticulate (resembling a net) chloroplast
-
1. Hydrodictyon reproduces __through the formation of many __ in each cell of the net, which are not released from __, but group themselves into geometric arrays of four to nine within the cylindrical parent cell
a. __then lose their __and form the component cells of daughter mini-nets
i. They are eventually released from the __ and grow into __ by dramatic cell enlargement
- asexually
- uninucleate, biflagellated zoospores
- parental cells
- Zoospores
- flagella
- parent cell
- mature nets
-
1. __is an example of an unbranched filamentous member
a. Filaments begin their developed __, but massive growths may later break away to form noticeable floating blooms
b. Their mode of cell division results in the formation of characteristic __
i. These scars reflect what?
- Oedogonium
- attached to underwater substrates by a holdfast
- “caps” or annular scars with each cell division
- the number of division that has occurred in a given cell
-
i. Filamentous and Parencymatous Chlorophyceae
1. The __ and __include algae that have the most complex structures found in the calss
a. Their cells can be __with respect to particular functions or positions in the algal body and , like plant cells, are sometimes connected by __
- branched filamentous and parencymatous (tissuelike)
- specialized
- plasmodesmata
|
|