Bio Unit #1 Test - Diversity of Life Flashcards
Explain why Biodiversity is important to maintain?
Biodiversity is crucial for ecosystem stability, resilience, and productivity. It provides:
ability to adapt and survive disturbances/changes
-Ecosystem Stability: Biodiversity ensures ecosystem resilience and balance.
-Resources: Provides food, medicine, and materials.
-Ecosystem Services: Pollination, water purification, oxygen production, etc.
-Genetic Diversity: Allows adaptation to environmental changes.
Compare and Contrast a Eukaryotic cell and a Prokaryotic Cell?
prokaryotic: no nucleus, no membrane bound organelles, small size, binary fission (bacteria, archaea bacteria)
eukaryotic: nucleus, membrane bound organelles (plants, animals, fungi, protists)
Describe the defining characteristics of each of the kingdoms?
-Animalia: Multicellular, heterotrophic, no cell walls, motile.
-Plantae: Multicellular, autotrophic (photosynthesis), cell walls (cellulose).
-Fungi: Multicellular/unicellular, heterotrophic (decomposers), cell walls (chitin).
-Protista: Diverse, mostly unicellular, can be autotrophic or heterotrophic.
-Bacteria: Unicellular, prokaryotic, various metabolism types.
-Archaea: Unicellular, prokaryotic, extreme environments, different cell membranes than bacteria.
Describe the difference between the different domains? metabolism
eubacteria: Prokaryotic, peptidoglycan cell walls, found everywhere (most populistic)
Archaea: Prokaryotic, live in extreme environments, unique lipids in the membrane.
Eukaryota: multicellular, includes plants, animals, fungi, and protists.
-all have cells
describe structures common to all viruses (4)
- Genome/ nucliec acid: DNA or RNA.
- Require host
- Envelope -> capsid, antigens
- Transmission
describe the hierarchy of classification or order of taxonomic ranks
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species (Mnemonic: dear king philip came over for great spaghetti).
Explain what a phylogenetic tree shows you and how it works?
A phylogenetic tree shows evolutionary relationships. Branches represent common ancestors, and species that share a branch are more closely related.
describe what is binomial nomenclature, why is it used and provide examples
-Definition: Two-part scientific naming system (Genus species).
-Why Used: Universal and avoids language barriers.
-Why Latin: It’s a dead language, so meanings don’t change.
-Example: Homo sapiens (humans), Canis lupus (wolf).
Describe the benefits and drawbacks of each of the species concepts?
biological
benefits: widely used by scientists
drawback: doesn’t work for asexual species
morphological
benefits: simple
drawback: can be subjective, how much difference is too much
phylogenetic
benefits: can be applied to extinct species, considers DNA analysis
drawbacks: evolutionary history is not known for all species
Describe the two methods by which viruses reproduce?
Lytic cycle
1. Attachment - proteins on the surface of the virus bind to the protein receptors on the surface of the host cells membrane
2. Entry - virus injects its material into host
3. Provirus formation - viral DNA becomes part of the host cells chromosome
4. replication
5. assembly
6. lysis and release
Lysogenic cycle
1. Attachment - proteins on the surface of the virus bind to the protein receptors on the surface of the host cells membrane
2. Entry - virus injects its material into host
3. Provirus formation - viral DNA becomes part of the host cells chromosome
4. Cell division - provirus replicates with hosts chromosome
5. trigger intro continuing lytic cycle
Explain why viruses are specific to certain species?
Viruses have surface proteins that must match receptors on a host cell (lock-and-key model). Example: HIV only infects human T-cells.
Describe how bacteria are categorized by shape and metabolism?
Shape:
-Coccus (spherical)
-Bacillus (rod)
-Spirillum (spiral)
Metabolism:
-Obligate aerobes (need oxygen)
-Obligate anaerobes (no oxygen)
-Facultative anaerobes (can live without oxygen but prefers oxygen).
Apply what I know about the optimum growing conditions of bacteria to different scenarios? (where would u store it, one way to protect bacteria growth from equipment, food, ect.)
Bacteria thrive in warm, moist, dark environments
Refrigeration slows growth, heat kills bacteria, salt dehydrates them.
ex. shoes: are dark, moisture, and warm. dry out shoes in sunlight, use disinfectants, dry/ventilation shoe rack
Describe and Draw each stage of Binary Fission?
DNA replication
Cell elongation
Septum formation
Cell division
describe the result of binary fission
Two genetically identical daughter cells.
Explain how antibiotic resistance occurs?
How It Occurs:
Bacteria can develop resistance through mutations or by acquiring resistance genes from other bacteria (conjugation).
Overuse or misuse of antibiotics speeds up resistance development.
Why It Occurs:
Natural selection: Resistant bacteria survive and multiply when antibiotics kill non-resistant bacteria.
Horizontal gene transfer: Bacteria share resistance genes through plasmids.
measles immunization
Compare and contrast the terms endemic, pandemic, and epidemic?
Endemic: Disease constantly present in a region (e.g., malaria in Africa).
Epidemic: Sudden outbreak in a region (e.g., Ebola outbreak).
Pandemic: Global spread of a disease (e.g., COVID-19).
vector
organism that spreads disease (ex. mosquito for malaria)
zoonotic
disease that spreads from animals to humans
vaccine
stimulates immunity without causing disease
immunization
process of making the body resistant to infection
SARS
severe acute respiratory syndrome (coronavirus)
MERS
middle east respiratory syndrome
antigen
substance that triggers an immune response
RNA
single stranded genetic material in some viruses
retrovirus
Virus that reverse transcribes RNA to DNA (e.g., HIV).
Describe the envelope, host, genome, and transmission of at least 2 viruses?
HIV (Human Immunodeficiency Virus)
- Envelope: enveloped particles with a conical capsid
- Host: Humans, targets CD4+ T cells (immune cells).
- Genome: **Single-stranded, positive-sense RNA (ssRNA+), retrovirus (uses reverse transcriptase).
- Transmission: Sexual contact, blood exposure, breastfeeding
Rabies Virus
- Envelope: particles with a bullet-shaped helical capsid
- Host: Mammals (humans, dogs, bats, etc.), targets nerve cells (neurons).
- Genome: single-stranded, negative-sense RNA (ssRNA−)
- Transmission: Bites from infected animals, saliva touching eyes/mouth
Apply the characteristics of viruses (especially bacteriophages) to a scenario?
-bacteriophage will latch on to tail fibers
-spikes will connect to antigens
-requires you to know how structures work
Explain how an Antigenic Shift Occurs?
Two Different Viruses Infect the Same Host – Viruses from different species (e.g., bird flu and human flu) infect the same animal (like a pig).
Mixing of Genetic Material – Inside this intermediate host, the viruses swap and mix their genes, creating a brand-new virus.
New Virus Can Infect More Species – The new virus has different antigens (surface proteins), allowing it to jump between species, including humans.
Immune System Unprepared – Since the virus is completely new, our immune system doesn’t recognize it and has no antibodies to fight it, making it highly dangerous.
how to make sure an ecosystem is more resilient (inititives)
-diverse plants means more animals + more complex food web
-reduce pollution
-plant native species
-control/monitor invasive species
