Comprehensive Biology Study Guide: Viruses, Bacteria, Protists, Plants, and Reproduction

What is the structure of a virus?

A virus consists of a protein capsid made of capsomeres, nucleic acid (RNA or DNA), and may have a viral envelope.

What are the two cycles of bacteriophage replication?

The lytic cycle and the lysogenic cycle.

What is a prophage?

Inserted viral genetic material in the lysogenic cycle.

What is the role of reverse transcriptase in retroviruses?

It copies RNA genome into DNA, which can integrate into the host as a provirus.

What is the host range of a virus?

The specific types of cells or organisms a virus can infect, often narrow.

What is a virion?

A viral particle.

What distinguishes bacteria from archaea?

Bacteria lack a membranous nucleus and have unique biochemistry that separates them from archaea.

What are Koch's postulates?

A set of criteria to establish a causative relationship between a microbe and a disease.

What are the three general shapes of prokaryotes?

Coccus (spherical), bacillus (rod-shaped), and spirillum (spiral-shaped).

What is the difference between Gram-positive and Gram-negative bacteria?

Gram-positive bacteria retain violet dye, while Gram-negative bacteria stain red due to a thinner peptidoglycan layer.

What are plasmids?

Independent circular DNA pieces that can confer antibiotic resistance.

What are the nutritional types of bacteria?

Obligate aerobes, obligate anaerobes, and those that can perform nitrogen fixation.

What is the endosymbiotic hypothesis?

The theory that early eukaryotes acquired bacteria that became organelles like mitochondria and chloroplasts.

What are the characteristics of protists?

Eukaryotic, diverse, can be unicellular or multicellular, and include photoautotrophs and symbionts.

What is the significance of Chlamydomonas in the study of multicellularity?

It is a single-celled alga that may be a precursor to multicellular forms like Volvox.

What are the three main groups of algae?

Green algae (Chlorophyta), red algae (Rhodophyta), and brown algae (Phaeophyta).

What is a heterocyst?

A specialized cell in some cyanobacteria that carries out nitrogen fixation.

What diseases are associated with the following viruses: HIV, Measles, Influenza?

HIV causes AIDS, Measles is caused by the measles virus, and Influenza causes the flu.

What is the role of biofilms in bacteria?

Biofilms allow bacteria to cooperate and exploit environmental resources.

What are prions?

Misfolded proteins that cause brain diseases and are hard to destroy.

What is the significance of the 1918 Spanish flu?

It is an example of an emerging virus that had a significant impact on human health.

What is the function of the viral envelope?

It is derived from the host cell membrane and helps the virus enter host cells.

What are the characteristics of extreme halophiles?

Archaea that live in high salt concentrations.

What is the difference between transformation and transduction in bacteria?

Transformation involves uptake of DNA from the environment, while transduction involves transfer of DNA via a virus.

What is the significance of the term 'obligate intracellular parasites' in relation to viruses?

Viruses cannot reproduce independently and must infect host cells to replicate.

What is the role of the capsid in a virus?

The capsid protects the viral genetic material and aids in the delivery of the genome into host cells.

What are carbohydrates stored as in seaweed?

Laminarin

What is a major component of phytoplankton?

Diatoms

What is the locomotion method used by protists?

Cilia, pseudopodia, and flagella

What is endosymbiosis?

The process by which mitochondria and plastids became organelles

What are the four supergroups of eukaryotes?

Excavata, Archaeplastida, SAR, and Unikonta

What characterizes diplomonads?

They have mitosomes, which are simplified mitochondria

What do parabasalids possess?

Simpler mitochondria called hydrogenosomes

What is a key feature of euglenozoans?

They have a crystalline rod in their flagellum and a kinetoplast

What pigment gives red algae their color?

Phycoerythrin

What is the significance of alternation of generations?

It is a reproductive cycle seen in algae and plants

What is the role of fungi in ecosystems?

Decomposition, mutualism, and as pathogens

What do fungi have in their cell walls instead of cellulose?

Chitin

What is the difference between coenocytic and septate fungi?

Coenocytic fungi lack septa, while septate fungi have septa

What is plasmogamy in fungal reproduction?

The union of plasma membranes

What is karyogamy in fungal reproduction?

The union of haploid nuclei

What are microsporidia?

Primitive fungi that are single-celled

What is the primary form of moss in its life cycle?

Gametophyte form

What do gymnosperms lack compared to angiosperms?

Flowers and fruits

What is the main structure seen in the fern life cycle?

Sporophyte form

What are the two types of spores produced by heterosporous plants?

Megaspores and microspores

What is the significance of mycorrhizae in plants?

They help plants absorb nutrients and water from the soil

What is the role of apical meristems in plants?

They allow for growth in shoots and roots

What is the function of the waxy cuticle in plants?

To protect leaves from drying out

What is the difference between monocots and dicots?

Monocots have one cotyledon, while dicots have two

What is the significance of lignin in plant cell walls?

It provides structural support

What is the main characteristic of brown algae?

They are multicellular stramenopiles resembling plants

What is a red tide?

A phenomenon caused by dinoflagellates that can deplete oxygen in water

What is the primary reproductive method of Paramecium?

Conjugation

What is the difference between plasmodial and cellular slime molds?

Plasmodial slime molds are multinucleate, while cellular slime molds consist of autonomous amoebas

What distinguishes monocots from dicots?

Monocots have one cotyledon, while dicots have two.

What are heterosporous plants?

Plants that produce two kinds of spores: megaspores (female gametophytes) and microspores (male gametophytes).

Why are seeds and pollen grains important for land plants?

They are adaptations for life on land, allowing reproduction without water.

What are gymnosperms?

Plants with naked seeds on scales of cones, lacking fruits and flowers.

What is a key characteristic of conifers?

They bear cones and have needle-like leaves.

What are cycads?

Plants that resemble palms but have cones and large compound leaves.

What is unique about Ginkgophytes?

They include Ginkgo biloba, known for high pollution resistance and having male and female trees.

What is the significance of double fertilization in angiosperms?

It leads to the formation of endosperm, which provides nourishment to the developing embryo.

What are the male and female parts of a flower?

The carpel is female (stigma, style, ovary), and the stamen is male (filament, anther).

What is the difference between complete and incomplete flowers?

Complete flowers have both male and female parts; incomplete flowers have only one type.

What are the three types of plant organs?

Roots, stems, and leaves.

What are the types of roots and their adaptations?

Types include prop roots, aerial roots, storage roots, and pneumatophores.

What are the three types of plant tissues?

Dermal, vascular, and ground tissue.

What are parenchyma, collenchyma, and sclerenchyma?

Types of differentiated plant cells: parenchyma (flexible), collenchyma (uneven thickness), and sclerenchyma (lignified and dead at maturity).

What role do tracheids and vessel elements play in plants?

They are water conduction cells of xylem, with tracheids being long and thin and vessel elements being tube-like.

What is the function of sieve tube elements and companion cells in phloem?

Sieve tube elements conduct sugars, while companion cells support them.

What is apical dominance?

The suppression of lateral axillary buds by a stem's apical meristem.

What is the role of cork cambium in plants?

It produces cork, which is impermeable to water and gases, forming the periderm.

What are the phases of plant growth?

Determinate growth (fixed size) and indeterminate growth (continuous growth).

What are the parts of a fruit?

Exocarp (outer layer), mesocarp (fleshy part), and endocarp (inner layer).

How are seeds and fruits dispersed?

Through wind, animals, water, and other means.

What is the significance of vernalization in seed dormancy?

It refers to the cold exposure that some seeds require to break dormancy.

What is the role of water in seed germination?

Water is essential for breaking dormancy and initiating germination.