analyse_media
The Latin name of this parasite is:
Ixodes ricinus
(Castor Bean Tick / Sheep Tick / Deer Tick)
Key morphological features confirming the ID:
| Feature | What's visible |
|---|---|
| Scutum | Dark brown-black, inornate (no pale markings), covers only the anterior portion - indicating an unfed female |
| Abdomen (alloscutum) | Bright reddish-orange/brick-red - highly distinctive for Ixodes females |
| Legs | Uniformly dark, no banding or pale rings (rules out Dermacentor, Hyalomma) |
| Mouthparts | Long projecting palps - a key genus-level feature of Ixodes |
| Posterior margin | Smooth - no "festoons" (which would indicate Rhipicephalus or Dermacentor) |
Why Ixodes ricinus specifically:
- It is the most widespread hard tick in Europe and the standard species used in parasitology curricula
- The reddish abdomen + black legs + dark scutum combination is the classic textbook presentation of a female I. ricinus
- Ixodes scapularis (North American equivalent) is morphologically nearly identical but typically appears in North American academic contexts
Medical significance:
Ixodes ricinus is a vector for Borrelia burgdorferi (Lyme disease), Tick-borne encephalitis virus (TBE), Anaplasma phagocytophilum, and Babesia spp.## Answer: Polygenically
Traits with a broad reaction norm (широкая норма реакции) are controlled polygenically - by multiple genes acting together.
Why:
- Reaction norm describes the range of phenotypes a single genotype can produce across different environments
- A broad reaction norm means the trait shows a wide range of variation in response to environmental conditions
- This wide plasticity is characteristic of polygenic traits - those controlled by many genes (also called quantitative traits), such as height, skin color, body mass, intelligence
- Polygenic traits produce continuous variation and are highly sensitive to environmental influence - exactly what a broad reaction norm describes
Why the other options are wrong:
| Option | Why incorrect |
|---|---|
| Sex-linked genes | Determines which chromosome carries the gene, not the breadth of environmental response |
| Monogenically | Single-gene traits typically show discrete (either/or) phenotypes - a narrow reaction norm |
| Autosomes | Describes chromosome location, not mode of inheritance or plasticity |
| Genes dependent on sex hormones | Describes sex-influenced/sex-limited traits, unrelated to reaction norm breadth |
**The correct answer is: Polygenically.**This is the same question as before — the answer is the same:
✅ Polygenically
Traits with a broad reaction norm are controlled by multiple genes (polygenic inheritance), which allows the phenotype to vary widely across different environmental conditions — producing the continuous, plastic variation that defines a broad norm of reaction.## Answer: bite of Ornithodorus papillipes
Reasoning:
The scenario describes:
- Location: Kyzyl-Kuma desert area, Uzbekistan (Central Asia)
- Setting: Abandoned mud-brick building (overnight stay)
- Disease: Recurrent (relapsing) typhus - this is actually tick-borne relapsing fever caused by Borrelia recurrentis / Borrelia sogdiana
Why Ornithodorus papillipes:
| Factor | Detail |
|---|---|
| Vector | Ornithodorus papillipes is a soft tick (Argasidae) - the classic vector of tick-borne relapsing fever in Central Asia |
| Habitat | Lives in rodent burrows, caves, and mud-brick buildings - feeds at night on sleeping people |
| Bite | Painless, nocturnal, very brief (minutes) - victims often don't notice |
| Geography | Endemic to Uzbekistan, Turkmenistan, Tajikistan - precisely the Kyzyl-Kuma region |
| Disease | Transmits Borrelia spp. causing relapsing fever (repeated febrile episodes) |
Why the other options are wrong:
- Rubbing hemolymph of Pediculus humanus humanus - this IS how epidemic typhus (Rickettsia prowazekii) spreads, but that's classic typhus, not recurrent/relapsing typhus
- Pulex irritans regurgitation - causes plague (Yersinia pestis), not relapsing fever
- Bite of Ixodes ricinus - transmits Lyme disease and TBE, not relapsing fever; also not endemic to desert mud buildings
- Failure to observe hygiene - non-specific, not a cause of relapsing fever
- Rubbing feces of Pediculus humanus capitis - head lice are not vectors of typhus (body lice are), and this is not relapsing fever
**The key clue is the combination of: abandoned mud-brick building + Central Asian desert + relapsing fever = Ornithodorus papillipes.**Same question as before — answer unchanged:
✅ Bite of Ornithodorus papillipes
The three decisive clues are:
- Mud-brick abandoned building in the Kyzyl-Kuma desert, Uzbekistan - classic habitat of Ornithodorus papillipes (a soft tick that lives in cracks of mud walls and rodent burrows)
- Nocturnal bite - soft ticks feed briefly at night, unnoticed by sleeping hosts
- Recurrent (relapsing) fever/typhus - transmitted by Borrelia sogdiana via O. papillipes, causing repeated febrile episodes## Answer: Fungi and prokaryotes
Reasoning:
Decomposers (Reducers) break down dead organic matter into inorganic substances, completing the nutrient cycle in ecosystems.
The two main groups are:
| Group | Role |
|---|---|
| Fungi | Secrete extracellular enzymes to break down complex organic molecules (cellulose, lignin, chitin). Primary decomposers of plant material. |
| Prokaryotes (bacteria) | Break down a vast range of organic compounds, including proteins and lipids. Found in soil, water, and within decomposing matter. |
Why the others are wrong:
- Plants - are producers (autotrophs), not decomposers
- Animals - are consumers, not decomposers (some are detritivores, but not true decomposers/reducers)
- Prokaryotes and animals - animals are consumers, not decomposers
- Plants and animals - neither are decomposers
The correct answer is: Fungi and prokaryotes.## Answer: ACG
Reasoning:
The mRNA codon is UGC. To find the corresponding DNA triplet (template strand), apply complementary base pairing rules, remembering that DNA uses T instead of U:
| mRNA codon | U | G | C |
|---|---|---|---|
| DNA template | A | C | G |
mRNA is transcribed from the template (antisense) strand of DNA using complementary pairing:
- U pairs with A
- G pairs with C
- C pairs with G
So the DNA triplet = ACG
Why the others are wrong:
| Option | Why wrong |
|---|---|
| AGC | Complement of UGA, not UGC |
| TCG | This is the coding (sense) strand equivalent (DNA copy of mRNA, not the template) |
| TGC | This is the coding strand written with T instead of U - not the template strand |
| TSG | "S" is not a DNA base - invalid |
The correct answer is: ACG## Answer: 2 correct answers:
✅ 2 strands of the division spindle are attached to the chromosome
✅ Bivalents lining up in the equatorial region
Reasoning - What happens in Metaphase I of meiosis:
| Event | Metaphase I? |
|---|---|
| Bivalents (tetrads = paired homologs) align at the metaphase plate (equatorial region) | ✅ YES - defining feature |
| 2 spindle fibers attach to each chromosome (one from each pole attaches to the same kinetochore of the bivalent) | ✅ YES |
| Crossingover of homologous chromosomes | ❌ NO - occurs in Prophase I |
| Conjugation (synapsis) of homologous chromosomes | ❌ NO - occurs in Prophase I (zygotene) |
| Chromosomes located at cell's equator | ⚠️ Partially true but vague - the bivalents align there, so this overlaps with "bivalents lining up..." |
| 1 strand of spindle attached | ❌ NO - in Metaphase I each bivalent has 2 spindle fibers (one per homolog, from opposite poles) |
| Divergence of homologs toward poles | ❌ NO - occurs in Anaphase I |
Key distinction - Metaphase I vs Metaphase II:
- Metaphase I: Bivalents (pairs of homologs) align at equator; 2 spindle fibers per bivalent
- Metaphase II: Individual dyads (single chromosomes) align; 1 spindle fiber per chromosome (like mitosis)
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