Biology 121 Lab Exam 1

Diatoms are classified under the Phylum Bacillariophyta due to their unique characteristics and evolutionary history.

Diatomaceous Earth is a powdery substance made up of the fossilized remains of diatoms. It is commonly used in organic farming and gardening as a natural insecticide and pesticide due to its abrasive texture that damages the exoskeleton of insects, leading to dehydration and death. Salt, vinegar, and baking soda do not have the same abrasive properties as diatomaceous earth.

Brown Algae, commonly known as seaweeds, belong to the Phylum Phaeophyta. Chlorophyta, Rhodophyta, and Ochrophyta are other phyla of algae, but they do not include Brown Algae species.

Red Algae belongs to the Phylum Rhodophyta, which is characterized by red pigments and is commonly found in marine environments.

Green Algae, belonging to the Phylum Chlorophyta, are a diverse group of photosynthetic organisms known for their green coloration.

Unicellular Chlorophyta are green algae that consist of a single cell. Mixed Desmids are an example of unicellular Chlorophyta, which includes species like Micrasterias and Closterium. Chlamydomas, on the other hand, is a different genus of green algae and not an example of Unicellular Chlorophyta.

Micrasterias is a genus of desmid green algae commonly found in freshwater habitats like ponds and lakes. While Euglena, Paramecium, and Diatoms are also common microorganisms, they belong to different groups and are not specifically known to inhabit freshwater environments as prominently as Micrasterias.

Closterium is a genus of green algae which fits the description provided in the question. Spirogyra, Volvox, and Chlamydomonas are different genera of green algae with distinct characteristics.

Chlamydomonas is a genus of green algae commonly found in freshwater environments. Cyanobacteria are actually a type of photosynthetic bacteria. Euglena is a protist that can be photosynthetic or heterotrophic. Diatoms are a major group of algae, but they are typically found in marine and freshwater environments.

Chlamydomas follows the life cycle of Zygote (2N) - Meiosis - Zoospores - Isogametes - Fusion of gametes (syngamy) - Fusion of nucleus - Zygote. The incorrect answers are variations that do not align with the known lifecycle of Chlamydomas.

Colonial Phylum Chlorophyta consists of various green algae species that exhibit colonial growth forms. While Volvox is a colonial green alga, Spirogyra, Chlamydomonas, and Ulva belong to other genera within the same phylum.

Volvox is a type of multicellular green algae that forms hollow spherical colonies embedded in jelly-like material. The cells of Volvox colonies can detach and form daughter colonies inside the parent cell.

Filamentous Phylum Chlorophyta refers to green algae that are commonly found in freshwater environments. Spirogyra is a type of filamentous green algae that belongs to the Chlorophyta phylum, known for its spiral-shaped chloroplasts.

Spirogyra is a type of filamentous green algae that can be found in freshwater habitats. Chlamydomonas is a unicellular green algae, diatoms are single-celled algae with a silica shell, and kelp is a type of brown algae typically found in marine environments.

Spirogyra reproduces via conjugation, a process where two filaments come together, exchange genetic material, and form zygospores.

Conjugation tube is a structure in bacteria specifically designed for the transfer of genetic material, while the other options listed are not involved in this specific process.

Spirogyra is a type of filamentous green algae commonly found in freshwater habitats. Its bright green color is due to the presence of chlorophyll in its cells.

Oedogonium is a genus of filamentous green algae commonly found in freshwater habitats, characterized by their unbranched filaments.

Holdfast is the specialized cell at the end of the filament for attachment of Oedogonium. Stipe, Rhizoid, and Pseudopodia are not directly related to this function.

In Oedogonium, pyrenoids are specialized structures within the chloroplasts that contain starch bodies. Pyrenoids play a key role in starch storage and synthesis in photosynthetic organisms like Oedogonium.

Heterogametes refer to gametes that are structurally and functionally different from each other, such as sperm and eggs. Isogametes are gametes that are similar in size and structure. Autogametes are gametes that are produced by the same individual. Anisogametes are gametes that differ in size and shape but are both motile.

In Oedogonium, sperm are produced in specialized small cells called antheridium. Antheridium is the structure that produces and releases sperm cells in certain algae and plants.

Antheridium is responsible for producing male gametes in plants, while Oogonium is responsible for producing female gametes. Stigma and Style are part of the female reproductive system, Pistil and Stamen are both parts of the flower's reproductive system, and Sepal and Petal are not directly involved in gamete production.

In Oedogonium, the egg cells form inside specialized cells called oogonia, not antheridia, zoospores, or sporangia.

The life cycle of Oedogonium involves the release of sperm from antheridium, fertilization of egg, meiosis, and the formation of 4 haploid zoospores. The incorrect answers provided do not accurately describe the life cycle stages of Oedogonium.

Oedogonium is a type of filamentous green algae, and its specialized cell types include holdfast (for attachment), antheridium (male reproductive structure), and Oedogonium itself (the main body).

Sea Lettuce is scientifically known as Ulva, while the other options are different types of seaweeds with distinct characteristics.

The correct answer is 'Thallus'. Thallus refers to the undifferentiated plant body of algae like Ulva, which lacks distinct leaves, stems, or roots. Stamen, Pistil, and Sepal are parts of a flower and not related to the plant body of Ulva.