eyespot apparatus

Pigment structure and photoreception

Record the pigment structure and associated photoreceptive components separately before asserting the complete apparatus. Terminology can distinguish the eyespot from the larger apparatus. Source: [Kato et al.](https://pmc.ncbi.nlm.nih.gov/articles/PMC7155050/).

1. Does 'eyespot' in this observation mean the pigment globules or the complete photoreceptive apparatus? definition
2. What evidence associates the observed pigment structure with photoreceptive components? provenance

Compartment pattern

Chlamydomonas and Euglena demonstrate different pigment and receptor compartment arrangements; record the observed arrangement without assuming evolutionary equivalence. Source: [Kato et al.](https://pmc.ncbi.nlm.nih.gov/articles/PMC7155050/).

1. Which taxon, strain, and cellular stage support the proposed architectural identification? provenance
2. Which components lie in the chloroplast, cytosol, plasma membrane, or paraflagellar region? boundary

Array structure

Measure globule size, packing, and layer organisation where present. Ordered chloroplast globule layers are documented in Chlamydomonas reinhardtii. Source: [Schmidt et al.](https://pmc.ncbi.nlm.nih.gov/articles/PMC1533972/).

1. What globule dimensions, packing pattern, and layer count are resolved by the imaging method? measurement
2. Which observations distinguish eyespot globules from neighbouring lipid bodies or other pigment deposits? boundary

Optical effect

Distinguish measured shielding or reflection from proposed mechanisms. Euglena eyespots should not automatically inherit the reflective role attributed to ordered algal arrays. Source: [Kato et al.](https://pmc.ncbi.nlm.nih.gov/articles/PMC7155050/).

1. How does illumination at the receptor vary with light direction relative to the pigment structure? measurement
2. Is the assigned shielding or reflective role measured in this host or inferred from another system? provenance

Localised light detection

Record receptor identity, localisation, and stimulus-response evidence independently. Channelrhodopsins are documented photoreceptors in Chlamydomonas reinhardtii; this identity is not a universal eyespot requirement. Source: [Kato et al.](https://pmc.ncbi.nlm.nih.gov/articles/PMC7155050/).

1. Which receptor is supported by molecular and localisation evidence in this host? provenance
2. What wavelength, irradiance, and response latency characterise the measured receptor activity? measurement

Photobehaviour readout

Record movement toward or away from a light direction separately from transient avoidance responses, and qualify attribution to the apparatus with motility controls.

1. Does the assay measure directional phototaxis, a transient light response, or a change in swimming speed? definition
2. Which control shows that an altered response is not explained by loss of flagellar motility? action

Assembly context

Chlamydomonas reinhardtii eyespots assemble after division and associate with a defined microtubule rootlet; apply this pattern only where supported. Source: [Boyd et al.](https://pubmed.ncbi.nlm.nih.gov/21372178/).

1. At what cell-cycle stage was apparatus formation or reorganisation observed? measurement
2. What evidence links apparatus position to a cellular landmark or assembly factor in this host? provenance

Structural defect classification

Classify observed defects by affected component rather than assigning a single functional state from spot visibility.

1. Are pigment globules, receptor localisation, component alignment, or several of these altered? measurement
2. What additional observation is needed before a visually undetected apparatus can be classified as absent? action

Assay interpretability

Associate each result with cell preparation, illumination history, spatial resolution, and whether the specimen was alive or fixed.

1. Was the apparatus observed in a live, fixed, sectioned, or isolated preparation? provenance
2. What resolution and illumination history limit conclusions about component alignment or light sensitivity? measurement

Perturbation attribution

Record the targeted pigment, receptor, or assembly process alongside possible host-cell effects and evidence of recovery or rescue.

1. Which apparatus component is targeted, and which other cellular processes could the intervention affect? boundary
2. Which matched control or rescue would support attributing the observed photobehaviour change to the apparatus? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these kinds and varieties hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance

Typical measurements

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these typical measurements hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of eyespot apparatus this model covers, and on what evidence? provenance