Sentence 1:
"One of the most captivating natural events of the year in many areas throughout North America is the turning of the leaves in the fall."
- Subject: "One of the most captivating natural events of the year in many areas throughout North America"
- Verb: "is"
- Chunks:
- "in many areas throughout North America" – A prepositional phrase specifying the location where this event is observed.
- "the turning of the leaves in the fall" – A noun phrase explaining what the event actually is.
- Meaning: This sentence describes the turning of leaves in autumn as a visually striking event commonly seen in North America.
- Punctuation Explanation: No special punctuation here. The sentence is straightforward, describing an event and its location.
Sentence 2:
"The colours are magnificent, but the question of exactly why some trees turn yellow or orange, and others red or purple, is something which has long puzzled scientists."
- Subject: "The question of exactly why some trees turn yellow or orange, and others red or purple"
- Verb: "is"
- Chunks:
- "are magnificent" – Describes the colors as beautiful, setting up a contrast.
- "but the question of exactly why some trees turn yellow or orange, and others red or purple" – Introduces the main point of the sentence, contrasting with the beauty of the colors.
- "which has long puzzled scientists" – A relative clause providing additional information about the "question."
- Meaning: Although the colors of leaves are beautiful, scientists have long been puzzled about why some trees change to different colors.
- Punctuation Explanation:
- Comma ( , ) – Separates contrasting ideas, first describing the colors as beautiful and then introducing the scientific question.
- "Which" – This relative pronoun introduces additional information about the "question," emphasizing that it has puzzled scientists.
Sentence 1:
"Summer leaves are green because they are full of chlorophyll, the molecule that captures sunlight and converts that energy into new building materials for the tree."
- Subject: "Summer leaves"
- Verb: "are"
- Chunks:
- "because they are full of chlorophyll" – A clause explaining why the leaves are green.
- "the molecule that captures sunlight and converts that energy into new building materials for the tree" – An appositive phrase that renames "chlorophyll" and describes its function.
- Meaning: Leaves are green in the summer because they contain chlorophyll, which helps the tree use sunlight for growth.
- Punctuation Explanation:
- Comma ( , ) – Separates the explanation about chlorophyll, which provides additional details about why the leaves are green.
- Participles:
- "capturing" and "converting" – Present participles that describe ongoing actions performed by chlorophyll, adding vividness to its role in photosynthesis.
Sentence 2:
"As fall approaches in the northern hemisphere, the amount of solar energy available declines considerably."
- Subject: "The amount of solar energy available"
- Verb: "declines"
- Chunks:
- "As fall approaches in the northern hemisphere" – A prepositional phrase indicating the time and location when this change happens.
- Meaning: As autumn comes in the northern hemisphere, there is less solar energy available for the trees.
- Punctuation Explanation:
- Comma ( , ) – Separates the introductory time and place phrase from the main clause, clarifying the sequence of events.
Sentence 3:
"For many trees – evergreen conifers being an exception – the best strategy is to abandon photosynthesis* until the spring."
- Subject: "The best strategy"
- Verb: "is"
- Chunks:
- "For many trees" – A prepositional phrase that specifies the type of trees.
- "evergreen conifers being an exception" – An appositive phrase using "being" to clarify that not all trees follow this strategy.
- Meaning: Most trees stop photosynthesis in fall to save energy, but evergreen trees are an exception to this.
- Punctuation Explanation:
- Em Dash ( – ) – Sets apart additional information about evergreen conifers as an exception, helping clarify that not all trees abandon photosynthesis.
Sentence 4:
"So rather than maintaining the now redundant leaves throughout the winter, the tree saves its precious resources and discards them."
- Subject: "The tree"
- Verbs: "saves" and "discards"
- Chunks:
- "rather than maintaining the now redundant leaves throughout the winter" – A gerund phrase explaining what the tree chooses not to do, showing contrast.
- Meaning: Instead of keeping its leaves through winter, the tree conserves energy by discarding them.
- Punctuation Explanation:
- Comma ( , ) – Separates the contrasting idea from the main action of the sentence.
Sentence 5:
"But before letting its leaves go, the tree dismantles their chlorophyll molecules and ships their valuable nitrogen back into the twigs."
- Subject: "The tree"
- Verbs: "dismantles" and "ships"
- Chunks:
- "before letting its leaves go" – A gerund phrase explaining the order of actions, describing what the tree does first.
- "back into the twigs" – A prepositional phrase specifying where the nitrogen is sent.
- Meaning: Before dropping its leaves, the tree breaks down chlorophyll to save nitrogen.
- Punctuation Explanation:
- Comma ( , ) – Separates the initial phrase, making the sequence of actions clearer.
- Participles:
- "letting" – Present participle used to describe the ongoing process of losing leaves.
Sentence 6:
"As chlorophyll is depleted, other colours that have been dominated by it throughout the summer begin to be revealed."
- Subject: "Other colours"
- Verb: "begin to be revealed"
- Chunks:
- "As chlorophyll is depleted" – A prepositional phrase showing the condition under which other colors appear.
- "that have been dominated by it throughout the summer" – A relative clause describing the hidden colors, with "dominated" as a past participle showing the completed effect of chlorophyll.
- Meaning: When chlorophyll fades, previously hidden colors start to show.
- Punctuation Explanation:
- Comma ( , ) – Separates the conditional phrase about chlorophyll from the main idea.
- Participles:
- "depleted" – Past participle (V3) showing that chlorophyll is now faded, allowing new colors to emerge.
Sentence 7:
"This unmasking explains the autumn colours of yellow and orange, but not the brilliant reds and purples of trees such as the maple or sumac."
- Subject: "This unmasking"
- Verb: "explains"
- Chunks:
- "but not the brilliant reds and purples of trees such as the maple or sumac" – A contrasting phrase indicating what this process doesn’t explain.
- Meaning: The fading of chlorophyll shows yellow and orange colors but does not explain the appearance of red or purple.
- Punctuation Explanation:
- Comma ( , ) – Separates contrasting information about what this process does and doesn’t explain.
Sentence 1:
"The source of the red is widely known: it is created by anthocyanins, water-soluble plant pigments reflecting the red to blue range of the visible spectrum."
- Subject: "The source of the red"
- Verb: "is"
- Chunks:
- "it is created by anthocyanins" – Clause explaining the cause of the red color.
- "water-soluble plant pigments reflecting the red to blue range of the visible spectrum" – Appositive phrase that describes "anthocyanins" and specifies their function.
- Meaning: The red color in leaves is caused by anthocyanins, pigments that reflect red and blue light.
- Punctuation Explanation:
- Colon ( : ) – Introduces an explanation of what causes the red color.
- Comma ( , ) – Separates additional information describing anthocyanins.
- Participles:
- "reflecting" (present participle) – Adds detail to describe the range of colors anthocyanins reflect.
Sentence 2:
"They belong to a class of sugar-based chemical compounds also known as flavonoids."
- Subject: "They" (referring to "anthocyanins")
- Verb: "belong"
- Chunks:
- "to a class of sugar-based chemical compounds also known as flavonoids" – Prepositional phrase describing what group anthocyanins belong to.
- Meaning: Anthocyanins are part of a larger group of sugar-based compounds called flavonoids.
- Punctuation Explanation: No special punctuation here; the sentence is straightforward.
Sentence 3:
"What’s puzzling is that anthocyanins are actually newly minted, made in the leaves at the same time as the tree is preparing to drop them."
- Subject: "What’s puzzling"
- Verb: "is"
- Chunks:
- "that anthocyanins are actually newly minted" – Clause explaining what’s puzzling about anthocyanins.
- "made in the leaves at the same time as the tree is preparing to drop them" – A participial phrase with "made," explaining that anthocyanins are produced right before leaf drop.
- Meaning: It’s surprising that trees produce anthocyanins just before the leaves are about to fall.
- Punctuation Explanation: No special punctuation, allowing the sentence to flow directly.
- Participles:
- "made" (past participle) – Used here to describe the process, adding a sense of timing and surprise.
Sentence 4:
"But it is hard to make sense of the manufacture of anthocyanins – why should a tree bother making new chemicals in its leaves when it’s already scrambling to withdraw and preserve the ones already there?"
- Subject: "It"
- Verb: "is"
- Chunks:
- "why should a tree bother making new chemicals in its leaves" – A rhetorical question embedded within the sentence, asking why the tree would produce anthocyanins.
- "when it’s already scrambling to withdraw and preserve the ones already there" – Dependent clause explaining the contradiction.
- Meaning: It’s confusing why trees would create new chemicals like anthocyanins when they’re already trying to save existing resources.
- Punctuation Explanation:
- Em Dash ( – ) – Separates the main statement from the rhetorical question, adding emphasis to the question.
- Participles:
- "scrambling" (present participle) – Describes the ongoing process of withdrawing resources.
Sentence 1:
"Some theories about anthocyanins have argued that they might act as a chemical defence against attacks by insects or fungi, or that they might attract fruit-eating birds or increase a leaf’s tolerance to freezing."
- Subject: "Some theories about anthocyanins"
- Verb: "have argued"
- Chunks:
- "that they might act as a chemical defence against attacks by insects or fungi" – A clause suggesting one theory, that anthocyanins protect against pests.
- "or that they might attract fruit-eating birds or increase a leaf’s tolerance to freezing" – Another clause listing alternative theories about anthocyanins' functions.
- Meaning: Some theories propose that anthocyanins might help protect leaves from pests, attract birds, or help them withstand cold.
- Punctuation Explanation:
- Comma ( , ) – Separates different ideas about the potential functions of anthocyanins.
Sentence 2:
"However there are problems with each of these theories, including the fact that leaves are red for such a relatively short period that the expense of energy needed to manufacture the anthocyanins would outweigh any anti-fungal or anti-herbivore activity achieved."
- Subject: "There"
- Verb: "are"
- Chunks:
- "However" – Transition word indicating a contrast or problem with the theories.
- "including the fact that leaves are red for such a relatively short period" – A clause specifying a key issue with these theories.
- "that the expense of energy needed to manufacture the anthocyanins would outweigh any anti-fungal or anti-herbivore activity achieved" – A clause explaining why anthocyanins may not serve a defensive purpose.
- Meaning: Each theory has issues, especially because leaves are red for only a short time, making it unlikely that anthocyanins provide significant protective benefits.
- Punctuation Explanation:
- Comma ( , ) – Separates the introductory phrase from the main clause.
- Participles:
- "needed" (past participle, V3) – Describes the energy required for making anthocyanins, adding detail about the cost involved.
Sentence 1:
"It has also been proposed that trees may produce vivid red colours to convince herbivorous insects that they are healthy and robust and would be easily able to mount chemical defences against infestation."
- Subject: "It"
- Verb: "has been proposed"
- Chunks:
- "that trees may produce vivid red colours to convince herbivorous insects" – A clause suggesting the purpose of red colors.
- "that they are healthy and robust and would be easily able to mount chemical defences against infestation" – A clause specifying what trees are signaling with red colors.
- Meaning: Another theory is that trees display red colors to signal strength, deterring herbivorous insects from attacking them.
- Punctuation Explanation: No special punctuation within this sentence; it flows directly without interruption.
Sentence 2:
"If insects paid attention to such advertisements, they might be prompted to lay their eggs on a duller, and presumably less resistant host."
- Subject: "They" (referring to insects)
- Verb: "might be prompted"
- Chunks:
- "If insects paid attention to such advertisements" – Conditional clause describing what would happen if insects notice the red color signal.
- "on a duller, and presumably less resistant host" – Prepositional phrase explaining where insects might lay eggs.
- Meaning: If insects noticed the red colors, they might choose to lay eggs on weaker trees instead.
- Punctuation Explanation:
- Comma ( , ) – Separates "duller" from the added description "presumably less resistant," clarifying the comparison.
Sentence 3:
"The flaw in this theory lies in the lack of proof to support it."
- Subject: "The flaw in this theory"
- Verb: "lies"
- Chunks:
- "in the lack of proof to support it" – Prepositional phrase indicating the reason why this theory is flawed.
- Meaning: The theory lacks evidence, which weakens its credibility.
- Punctuation Explanation: No special punctuation is used here; it’s a straightforward statement.
Sentence 4:
"No one has as yet ascertained whether more robust trees sport the brightest leaves, or whether insects make choices according to colour intensity."
- Subject: "No one"
- Verb: "has ascertained"
- Chunks:
- "whether more robust trees sport the brightest leaves" – A clause posing a question about the validity of the theory.
- "or whether insects make choices according to colour intensity" – Another clause exploring if insects select trees based on color brightness.
- Meaning: Scientists have not confirmed if stronger trees have brighter leaves or if insects choose trees based on color intensity.
- Punctuation Explanation:
- Comma ( , ) – Separates two different questions related to the theory.
Sentence 1:
"Perhaps the most plausible suggestion as to why leaves would go to the trouble of making anthocyanins when they’re busy packing up for the winter is the theory known as the ‘light screen’ hypothesis."
- Subject: "The most plausible suggestion"
- Verb: "is"
- Chunks:
- "as to why leaves would go to the trouble of making anthocyanins when they’re busy packing up for the winter" – A clause explaining why trees might produce anthocyanins in the fall.
- "the theory known as the ‘light screen’ hypothesis" – A noun phrase renaming "the most plausible suggestion," providing its name.
- Meaning: The best explanation for anthocyanin production in autumn is the "light screen" hypothesis.
- Punctuation Explanation: No special punctuation is used here other than the quotation marks around the theory’s name for emphasis.
Sentence 2:
"It sounds paradoxical, because the idea behind this hypothesis is that the red pigment is made in autumn leaves to protect chlorophyll, the light-absorbing chemical, from too much light."
- Subject: "It"
- Verb: "sounds"
- Chunks:
- "because the idea behind this hypothesis" – Introduces the reasoning behind the hypothesis.
- "is that the red pigment is made in autumn leaves to protect chlorophyll" – Main clause explaining the purpose of the red pigment.
- "the light-absorbing chemical" – An appositive renaming "chlorophyll" and clarifying its function.
- "from too much light" – Prepositional phrase specifying what chlorophyll is being protected from.
- Meaning: The "light screen" hypothesis suggests that red pigments help shield chlorophyll from excess light, which seems contradictory.
- Punctuation Explanation:
- Comma ( , ) – Separates the introductory comment "It sounds paradoxical" and the clause explaining the theory.
- Appositive ( , the light-absorbing chemical, ) – Adds a description of chlorophyll.
Sentence 3:
"Why does chlorophyll need protection when it is the natural world’s supreme light absorber?"
- Subject: "Chlorophyll"
- Verb: "need"
- Meaning: The sentence questions why chlorophyll, which absorbs light effectively, would require protection.
- Punctuation Explanation: No special punctuation here, as it’s a rhetorical question.
Sentence 4:
"Why protect chlorophyll at a time when the tree is breaking it down to salvage as much of it as possible?"
- Subject: "Why protect chlorophyll"
- Verb: "protect" (in infinitive form, acting as the main action in this rhetorical question)
- Chunks:
- "at a time when the tree is breaking it down to salvage as much of it as possible" – A clause explaining the paradox, given that the tree is already dismantling chlorophyll.
- Meaning: It questions why the tree would protect chlorophyll if it’s already being broken down for recycling.
- Punctuation Explanation: No special punctuation here, allowing the rhetorical question to flow naturally.
Sentence 1:
"Chlorophyll, although exquisitely evolved to capture the energy of sunlight, can sometimes be overwhelmed by it, especially in situations of drought, low temperatures, or nutrient deficiency."
- Subject: "Chlorophyll"
- Verb: "can be overwhelmed"
- Chunks:
- "although exquisitely evolved to capture the energy of sunlight" – Dependent clause giving background information about chlorophyll’s role.
- "especially in situations of drought, low temperatures, or nutrient deficiency" – A phrase listing conditions that increase chlorophyll’s sensitivity.
- Meaning: Even though chlorophyll is designed to absorb sunlight, it can be damaged under certain stressful conditions.
- Punctuation Explanation:
- Comma ( , ) – Separates the dependent clause from the main clause.
- Participles:
- "evolved" (past participle, V3) – Describes chlorophyll’s development, emphasizing its natural adaptation.
Sentence 2:
"Moreover, the problem of oversensitivity to light is even more acute in the fall, when the leaf is busy preparing for winter by dismantling its internal machinery."
- Subject: "The problem of oversensitivity to light"
- Verb: "is"
- Chunks:
- "even more acute in the fall" – Phrase specifying when oversensitivity becomes more pronounced.
- "when the leaf is busy preparing for winter by dismantling its internal machinery" – Clause explaining what happens to the leaf in the fall.
- Meaning: Light sensitivity in chlorophyll increases in autumn when the leaf starts breaking down internally.
- Punctuation Explanation:
- Comma ( , ) – Separates the introductory phrase from the main clause.
- Participles:
- "dismantling" (present participle) – Describes the ongoing process as the leaf prepares for winter.
Sentence 3:
"The energy absorbed by the chlorophyll molecules of the unstable autumn leaf is not immediately channelled into useful products and processes, as it would be in an intact summer leaf."
- Subject: "The energy absorbed by the chlorophyll molecules of the unstable autumn leaf"
- Verb: "is not immediately channelled"
- Chunks:
- "as it would be in an intact summer leaf" – Comparison phrase showing the difference in energy use between autumn and summer leaves.
- Meaning: In autumn, the energy chlorophyll absorbs isn’t efficiently used as it would be in the summer.
- Punctuation Explanation:
- Comma ( , ) – Separates the main clause from the comparative phrase.
- Participles:
- "absorbed" (past participle, V3) – Describes the energy, showing that it’s taken in but not efficiently used.
Sentence 4:
"The weakened fall leaf then becomes vulnerable to the highly destructive effects of the oxygen created by the excited chlorophyll molecules."
- Subject: "The weakened fall leaf"
- Verb: "becomes"
- Chunks:
- "to the highly destructive effects of the oxygen created by the excited chlorophyll molecules" – Describes what the leaf is vulnerable to.
- Meaning: Autumn leaves, weakened by chlorophyll breakdown, are at risk of damage from oxygen byproducts.
- Punctuation Explanation: No special punctuation is needed here.
- Participles:
- "created" (past participle, V3) – Describes the oxygen produced by chlorophyll, highlighting a consequence of chlorophyll’s activity.
Sentence 1:
"Even if you had never suspected that this is what was going on when leaves turn red, there are clues out there."
- Subject: "There"
- Verb: "are"
- Chunks:
- "Even if you had never suspected that this is what was going on when leaves turn red" – Conditional clause suggesting that one might not be aware of these clues.
- Meaning: There are visible signs of the processes involved in leaves turning red, even if these processes aren’t obvious to everyone.
- Punctuation Explanation:
- Comma ( , ) – Separates the conditional clause from the main clause, clarifying the two parts of the sentence.
Sentence 2:
"One is straightforward: on many trees, the leaves that are the reddest are those on the side of the tree which gets most sun."
- Subject: "One" (referring to a clue)
- Verb: "is"
- Chunks:
- "straightforward" – Predicate adjective describing the clue as clear or simple.
- "on many trees" – Prepositional phrase specifying where this clue applies.
- "the leaves that are the reddest" – Noun phrase with a relative clause "that are the reddest," describing which leaves show this feature.
- "on the side of the tree which gets most sun" – Prepositional phrase specifying the location of the reddest leaves.
- Meaning: One obvious clue is that the reddest leaves are often on the sunniest side of a tree.
- Punctuation Explanation:
- Colon ( : ) – Introduces an example or explanation of the clue being described.
Sentence 3:
"Not only that, but the red is brighter on the upper side of the leaf."
- Subject: "The red"
- Verb: "is"
- Chunks:
- "brighter on the upper side of the leaf" – Descriptive phrase specifying where the red color is most intense.
- Meaning: Another observation is that the red color is more intense on the top side of each leaf.
- Punctuation Explanation:
- Comma ( , ) – Separates "not only that" (an introductory phrase adding information) from the main clause.
Sentence 4:
"It has also been recognised for decades that the best conditions for intense red colours are dry, sunny days and cool nights, conditions that nicely match those that make leaves susceptible to excess light."
- Subject: "The best conditions for intense red colours"
- Verb: "are"
- Chunks:
- "for intense red colours" – Prepositional phrase specifying what the conditions are for.
- "dry, sunny days and cool nights" – Noun phrase listing the specific conditions that promote red color.
- "conditions that nicely match those that make leaves susceptible to excess light" – Appositive phrase describing these conditions as being favorable for excess light exposure.
- Meaning: For decades, it’s been known that dry, sunny days and cool nights are ideal for producing intense red colors in leaves.
- Punctuation Explanation:
- Comma ( , ) – Separates the main clause from the appositive phrase, adding additional information.
Sentence 5:
"And finally, trees such as maples usually get much redder the more north you travel in the northern hemisphere."
- Subject: "Trees such as maples"
- Verb: "get"
- Chunks:
- "much redder the more north you travel" – Comparative phrase explaining that trees tend to become redder at higher latitudes.
- "in the northern hemisphere" – Prepositional phrase specifying the location where this effect is observed.
- Meaning: Maple trees and similar species show more intense red colors the farther north you go in the northern hemisphere.
- Punctuation Explanation: No special punctuation is used here, as the sentence flows directly.
Sentence 6:
"It’s colder there, they’re more stressed, their chlorophyll is more sensitive and it needs more sunblock."
- Subjects: "It," "they," "their chlorophyll"
- Verbs: "is," "are," "is," "needs"
- Chunks:
- "It’s colder there" – Main clause describing the colder temperatures at northern latitudes.
- "they’re more stressed" – Main clause explaining that trees face more environmental stress.
- "their chlorophyll is more sensitive" – Main clause indicating that chlorophyll reacts more sensitively.
- "and it needs more sunblock" – Main clause summarizing the need for extra protection.
- Meaning: In northern areas, colder temperatures and increased stress make trees and their chlorophyll more sensitive, so they need more protection from sunlight.
- Punctuation Explanation:
- Commas ( , ) – Separate each clause, allowing for a list-like flow of related points.
Sentence 1:
"What is still not fully understood, however, is why some trees resort to producing red pigments while others don’t bother, and simply reveal their orange or yellow hues."
- Subject: "What is still not fully understood"
- Verb: "is"
- Chunks:
- "why some trees resort to producing red pigments" – Clause explaining part of the mystery.
- "while others don’t bother" – Contrasting clause showing that some trees do not produce red pigments.
- "and simply reveal their orange or yellow hues" – Additional clause indicating that some trees only show orange or yellow colors.
- Meaning: It’s still unclear why some trees produce red pigments while others don’t and instead reveal only orange or yellow colors.
- Punctuation Explanation:
- Comma ( , ) – Separates contrasting and additional information, clarifying the two different behaviors of trees.
Sentence 2:
"Do these trees have other means at their disposal to prevent overexposure to light in autumn?"
- Subject: "These trees"
- Verb: "have"
- Meaning: This rhetorical question suggests that some trees might have alternative ways to protect themselves from excessive sunlight in autumn.
- Punctuation Explanation: No special punctuation here, as it’s a direct question.
Sentence 3:
"Their story, though not as spectacular to the eye, will surely turn out to be as subtle and as complex."
- Subject: "Their story"
- Verb: "will turn out"
- Chunks:
- "though not as spectacular to the eye" – Concessive clause, acknowledging that these trees’ color changes may not be as visually striking.
- Meaning: The adaptation of trees that don’t produce red pigments is likely just as intricate, even if it’s not as visually impressive.
- Punctuation Explanation:
- Comma ( , ) – Separates the concessive clause from the main statement, allowing for a comparison between visual impact and complexity.