---
title: "Life Through the Seasons"
book: "Primary & Middle School Biology"
subject: biology
language: en
chapter: 38
exercises: 12
source: https://one-course.com/books/biology/1/en/chapter/38-life-through-the-seasons
---

# Chapter 38 — Life Through the Seasons

Photograph the same chestnut tree on the first of every month and pin the twelve pictures in a row: bare [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree), [buds](#def-g6-life-through-seasons-buds), [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts), candles of [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts), conkers, gold, bare [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree) again. Nothing moved — the tree stood still all year — and yet everything changed. [Chapter 20](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#ch-g3-animals-through-seasons) followed the [animals](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-animal) through the year; now, with a surveyor’s [eyes](https://one-course.com/books/biology/1/en/chapter/5-the-five-senses#def-g1-the-five-senses-sense), we follow the whole [environment](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-components), [plants](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) first.

## 38.1 The environment changes with the seasons

**Proposition 38.1 (Seasonal change of conditions).**

Through the year, an [environment](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-components)’s [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) ([Definition 37.4](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions)) swing widely: days shorten and lengthen, [temperatures](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) fall and rise, soil dampness follows rain and drought. A site surveyed in January and in June gives two different rows in the table — so, by [Proposition 37.6](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#prop-g6-exploring-our-environment-decide), expect two different casts of inhabitants.

**Proof.** *Admitted at this level.* ∎

**Example 38.2 (One hedge, two surveys).**

The lane’s hedge, surveyed twice. June: [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) dense, ten [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) [species](https://one-course.com/books/biology/1/en/chapter/30-biodiversity#def-g5-biodiversity-species) flowering at its foot, bees loud, blackbirds nesting, snails after rain. January: bare twigs, green reduced to ivy and moss, no insect flying, blackbirds foraging in the [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) litter, snails sealed in their [shells](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-covering) deep in the bank. Same place, same components list — living, mineral, traces — but the living column has transformed.

## 38.2 How plants pass the bad season

**Definition 38.3 (Deciduous and evergreen).**

Trees divide by their winter answer:

- *deciduous* trees — oak, chestnut, beech — drop all their [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) in autumn and stand bare;
- *evergreen* trees — pine, holly, ivy on the wall — keep working [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) all winter, usually tough, waxy or needle-shaped ones ( [Proposition 14.7](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-plants) met the needles already).

**Definition 38.4 (Buds).**

A [deciduous](#def-g6-life-through-seasons-trees) tree in winter is not dead: next spring is already packed on its twigs as *buds* — tiny complete shoots, [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) folded small, wrapped in weatherproof scales. Spring’s “new” [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) were built the summer before; the bud is winter storage for them.

**Example 38.5 (Opening a horse-chestnut bud).**

The horse chestnut’s big sticky [buds](#def-g6-life-through-seasons-buds) open well under a blade (a grown-up’s work): under the varnished scales, packed in cottony down, lie miniature folded [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) — perfect, pale, waiting. A twig cut in February and stood in water indoors “[leafs](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) out” weeks early: the shoots were finished; only warmth was missing.

![Winter storage, opened: inside the horse chestnut’s varnished bud scales, next spring’s leaves lie folded and finished.](https://one-course.com/images/onecourse/chapters/biology-1/g6-life-through-seasons/img-1eddfa4b1b05.jpg)

*Winter storage, opened: inside the horse chestnut’s varnished [bud](#def-g6-life-through-seasons-buds) scales, next spring’s [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) lie folded and finished.*

**Proposition 38.6 (The herb layer’s winter answers).**

Smaller [plants](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) have their own strategies:

- *annuals* — the poppy, the bean — die entirely in autumn and pass winter as *[seeds](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#prop-g3-flowers-fruits-seeds-transform)* ( [Proposition 9.5](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#prop-g2-from-seed-to-plant-needs) : a [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) waits out cold safely);
- *perennials* — the daffodil, the dandelion — let their tops die back and wait underground as [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) , [tubers](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) or tough rootstocks ( [Example 24.7](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) ’s storerooms, doing winter duty);
- [evergreens](#def-g6-life-through-seasons-trees) of the ground — moss, ivy — simply endure.

**Proof.** *Admitted at this level.* ∎

**Example 38.7 (Where did the daffodils go?).**

The daffodil patch [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) in March, yellows in May, and by July has vanished without trace — yet next March it returns, denser. All summer, autumn and winter it existed as [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) below the lawn: the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) never left; it withdrew to storage.

## 38.3 The animals’ calendar, revisited

**Proposition 38.8 (Animal answers, in survey terms).**

[Chapter 20](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#ch-g3-animals-through-seasons)’s three strategies — [migrate](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-migration), [hibernate](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-hibernation), [stay active](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-active) — now read as answers to the surveyed changes: each [species](https://one-course.com/books/biology/1/en/chapter/30-biodiversity#def-g5-biodiversity-species) tracks its own needed [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) and food.

- the swallow follows its food supply to where [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) keep [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups) flying;
- the hedgehog and the sealed snail wait out the months their bodies cannot work through;
- [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups) add a fourth answer: most pass winter as *[eggs](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born), larvae or chrysalises* ( [Example 8.8](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#ex-g2-animals-grow-up-butterfly) ) tucked in soil, bark or [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) litter — the adult dies, the [species](https://one-course.com/books/biology/1/en/chapter/30-biodiversity#def-g5-biodiversity-species) winters as its young stages.

**Proof.** *Admitted at this level.* ∎

**Example 38.9 (Where the June insects are in January).**

January’s hedge shows no insect — yet June’s are all present: the butterflies as chrysalises under the coping stones, the grasshoppers as [eggs](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born) in the soil, the ladybugs as huddled sleeping adults deep in the [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) litter, the bees as a tight warm cluster in the hive. The June survey walks about; the January survey must dig, lift and peer — the inhabitants have changed *form*, not address.

**Method 38.10 (Surveying through the year).**

To study a site’s seasonal life:

1. survey the same marked site ( [Method 37.8](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#met-g6-exploring-our-environment-survey) ) once each season — same square, same instruments, same search time;
2. record [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) *and* inhabitants each time; photograph the site from the same spot;
3. search winter’s hidden forms deliberately: [buds](#def-g6-life-through-seasons-buds) , [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) , [eggs](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born) , chrysalises, sealed snails — and put every cover back;
4. lay the four surveys side by side: pair each change of inhabitants with a change of [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) , and name each absentee’s winter form or destination.

**Remark 38.11 (Nothing simply vanishes).**

The year-round table teaches one deep rule: no [species](https://one-course.com/books/biology/1/en/chapter/30-biodiversity#def-g5-biodiversity-species) of the June survey has simply ceased. Each one is elsewhere (migrated), asleep (hibernating), in storage ([bulb](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber), [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed)), or in another life stage ([egg](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born), [chrysalis](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#ex-g2-animals-grow-up-butterfly)). “Gone” is never a full answer in [biology](https://one-course.com/books/biology/1/en/chapter/1-living-or-not-living#def-g1-living-or-not-living) — the follow-up question is always *gone where, as what?*

## 38.4 Exercises

**Exercise 38.1 ★.**

Which [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) of a site swing with the seasons? Name three.

**Solution of Exercise 38.1.**

Day length ([light](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions)), [temperature](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions), and soil or air dampness following rain and drought.

**Exercise 38.2 ★.**

[Deciduous](#def-g6-life-through-seasons-trees) or [evergreen](#def-g6-life-through-seasons-trees): oak, pine, beech, holly, horse chestnut? What does each word mean?

**Solution of Exercise 38.2.**

[Deciduous](#def-g6-life-through-seasons-trees) — drops all its [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) in autumn: oak, beech, horse chestnut. [Evergreen](#def-g6-life-through-seasons-trees) — keeps working [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) all winter: pine, holly.

**Exercise 38.3 ★.**

What is inside a winter [bud](#def-g6-life-through-seasons-buds), and when was it built?

**Solution of Exercise 38.3.**

A tiny complete shoot — miniature folded [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) wrapped in weatherproof scales. It was built the summer before.

**Exercise 38.4 ★.**

How does an [annual plant](#prop-g6-life-through-seasons-herbs) pass the winter? And a perennial like the daffodil?

**Solution of Exercise 38.4.**

The annual dies entirely and passes winter as [seeds](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#prop-g3-flowers-fruits-seeds-transform). The daffodil’s top dies back while the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) waits underground as a [bulb](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber).

**Exercise 38.5 ★.**

Explain [Example 38.5](#ex-g6-life-through-seasons-bud)’s February twig: why can it [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) out weeks early indoors?

**Solution of Exercise 38.5.**

Because the shoots inside its [buds](#def-g6-life-through-seasons-buds) were already finished last summer; the twig lacked only warmth, which the indoor water supplies weeks before the garden does.

**Exercise 38.6 ★.**

Give the four winter answers of [animals](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-animal), each with one [species](https://one-course.com/books/biology/1/en/chapter/30-biodiversity#def-g5-biodiversity-species).

**Solution of Exercise 38.6.**

[Migrate](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-migration): the swallow. [Hibernate](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-hibernation): the hedgehog (or the sealed snail). [Stay active](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-active): the fox, the magpie, the robin. Winter as young stages — [egg](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born), larva or [chrysalis](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#ex-g2-animals-grow-up-butterfly): most [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups), like the grasshopper or the butterfly.

**Exercise 38.7 ★★.**

For each June hedge inhabitant, name its January form and address: butterfly, grasshopper, ladybug, snail, swallow.

**Solution of Exercise 38.7.**

Butterfly: a [chrysalis](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#ex-g2-animals-grow-up-butterfly) under a coping stone. Grasshopper: [eggs](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born) in the soil. Ladybug: a sleeping adult huddled deep in [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) litter. Snail: sealed in its [shell](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-covering) in the bank. Swallow: in Africa, as its migrated self.

**Exercise 38.8 ★★.**

Why must the four seasonal surveys use the same site, instruments and search time? Which rule of [Chapter 37](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#ch-g6-exploring-our-environment) is at work?

**Solution of Exercise 38.8.**

So that any difference between the four tables comes from the seasons and not from the surveying — the fair-test rule of [Method 37.8](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#met-g6-exploring-our-environment-survey), applied across time instead of across sites.

**Exercise 38.9 ★★.**

The January hedge survey lists far fewer [living things](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-components) than June’s. Give two reasons the difference overstates the true loss, using [Example 38.9](#ex-g6-life-through-seasons-insects).

**Solution of Exercise 38.9.**

First, many “absentees” are present in hidden forms — [eggs](https://one-course.com/books/biology/1/en/chapter/8-how-animals-grow-up#def-g2-animals-grow-up-born), chrysalises, sleeping adults, [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) — that a walking-about survey misses without digging and lifting. Second, some are not lost but elsewhere: the [migrators](https://one-course.com/books/biology/1/en/chapter/20-animals-through-the-seasons#def-g3-animals-through-seasons-migration) will return. The January list understates residents and counts travelers as vanished.

**Exercise 38.10 ★★.**

A gardener digs up “dead” daffodil ground in August and finds firm [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber). Translate the find with [Proposition 38.6](#prop-g6-life-through-seasons-herbs): what state is the [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) in, and what will the [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) do in March?

**Solution of Exercise 38.10.**

The [plant](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) is in its underground storage state — alive, waiting as [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber). In March the [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) will send up [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) and [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) again, denser if the clumps have multiplied.

**Exercise 38.11 ★★.**

Apply [Remark 38.11](#rem-g6-life-through-seasons-vanish): a pond’s frogs are nowhere to be found in January. Give the two questions to ask, and the toad-and-frog answer to them.

**Solution of Exercise 38.11.**

Gone where, as what? Frogs winter dormant — buried in the pond’s mud bottom or in damp shelters on land — passing the cold months torpid until spring calls them back to the water to breed.

**Exercise 38.12 ★★★.**

[Evergreen](#def-g6-life-through-seasons-trees) [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) are tough, waxy or needle-shaped; [deciduous](#def-g6-life-through-seasons-trees) [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) are broad and thin. Propose what problem of winter the [evergreen](#def-g6-life-through-seasons-trees) [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts)’s build answers (think of the woodlouse’s water troubles in reverse), and why the [deciduous](#def-g6-life-through-seasons-trees) tree prefers to drop its thin [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) instead.

**Solution of Exercise 38.12.**

Winter’s problem for a working [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) is holding water: frozen ground gives [roots](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) almost none, while wind and sun keep drawing it out — the woodlouse’s drying problem, all winter long. The [evergreen](#def-g6-life-through-seasons-trees) [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts)’s wax and needle build cuts those losses to what the tree can afford. A broad thin [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) cannot be sealed so well; the [deciduous](#def-g6-life-through-seasons-trees) tree’s cheaper answer is to write its thin [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) off each autumn and store spring in [buds](#def-g6-life-through-seasons-buds) instead.

## 38.5 Problem: The Twelve Photographs

**Problem 38.1.**

Weekend problem — a year of the chestnut tree, read frame by frame

Lena photographs the chestnut tree by the gate on the first of every month for a year, and pins the twelve prints in a row. Under each print she notes day length and the morning’s [temperature](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions).

**Part I — Reading the row.**

1. January and December show bare [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree) . What, on the twigs, proves the tree is alive and spring-ready in both frames?
2. Between which two frames do the [buds](#def-g6-life-through-seasons-buds) burst open? Lena’s notes there read: days $11$ – $13$ hours, mornings $8$ – $12{}^{\circ}\mathrm{C}$ . Which changing [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) is the tree answering?
3. The May frame shows upright “candles” of white [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) . Using [Chapter 16](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#ch-g3-flowers-fruits-seeds) (or [Chapter 31](https://one-course.com/books/biology/1/en/chapter/31-from-flower-to-fruit#ch-g5-flower-to-fruit) ), what must visit between the May and September frames for October’s conkers to exist — and what is a conker, exactly?
4. The October frame shows gold [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) ; November’s, bare [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree) and a brown carpet below. Name the tree’s type from [Definition 38.3](#def-g6-life-through-seasons-trees) , and where its next spring is stored through the frames that follow.

**Part II — The tree’s neighbors.**

5. Under the tree, the March frame catches a patch of daffodils absent from the July frame. Where is the patch in July, and in what form?
6. Poppies edge the path in June; in the January frame their spot is bare earth. In what form is the poppy present in January, and by which strategy of [Proposition 38.6](#prop-g6-life-through-seasons-herbs) ?
7. The June frame catches a swallow above the tree and bees on the [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) below; neither appears from November to February. For each, say where it is then, and as what.
8. A magpie appears in every single frame. Which [animal](https://one-course.com/books/biology/1/en/chapter/2-animals-around-us#def-g1-animals-around-us-animal) strategy is that, and what must the magpie manage all winter that the swallow escapes by leaving?

**Part III — The rule of the row.**

9. Lena summarizes: “the tree’s year follows the [conditions](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) ’ year.” Support her with two pairings of a frame-to-frame change in the tree against a change in her day-length and [temperature](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) notes.
10. Her little brother says the July daffodil patch “died”. Correct him with [Remark 38.11](#rem-g6-life-through-seasons-vanish) — and state the follow-up question his word “gone” always deserves.
11. Predict frame 13 — next January’s photograph — in detail: [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree) , twigs, ground below. Which parts of your prediction are certain enough to bet on, and why?
12. A chestnut twig, cut in February and stood in warm water indoors, [leafs](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) out in three weeks. What does this show about *which* condition the [buds](#def-g6-life-through-seasons-buds) were waiting for — and design the twin-twig fair test ( [Method 22.1](https://one-course.com/books/biology/1/en/chapter/22-what-plants-need#met-g4-what-plants-need-fairtest) ) that would nail it down.

**Solution of Problem 38.1.**

**1.** The [buds](#def-g6-life-through-seasons-buds) on every twig — winter storage holding next spring’s shoots, built the previous summer.

**2.** Between the March and April frames (with the notes’ lengthening days and milder mornings). The tree answers the rising [temperature](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) and lengthening [light](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions).

**3.** Pollinating [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups) — bees above all — must visit the [flowers](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts), so that [pollen](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) reaches [pistils](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#def-g3-flowers-fruits-seeds-parts) and [fertilization](https://one-course.com/books/biology/1/en/chapter/31-from-flower-to-fruit#def-g5-flower-to-fruit-steps) follows. A conker is the [seed](https://one-course.com/books/biology/1/en/chapter/9-from-seed-to-plant#def-g2-from-seed-to-plant-seed) formed from a fertilized ovule, in its spiky [fruit](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#prop-g3-flowers-fruits-seeds-transform) case.

**4.** [Deciduous](#def-g6-life-through-seasons-trees). Its next spring rides the winter frames as [buds](#def-g6-life-through-seasons-buds) on the bare twigs.

**5.** Below the lawn, as [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) — the perennial’s underground storage.

**6.** As [seeds](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#prop-g3-flowers-fruits-seeds-transform) in the soil: the annual’s strategy — the [plants](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-plant) themselves died in autumn.

**7.** The swallow: in Africa, as its migrated self, following flying [insects](https://one-course.com/books/biology/1/en/chapter/14-sorting-living-things#prop-g3-sorting-living-things-groups). The bees: in the hive, as the winter cluster, warm around their queen.

**8.** Staying active. The magpie must find food through the leanest months — the very problem the swallow escapes by leaving.

**9.** For example: [buds](#def-g6-life-through-seasons-buds) burst (March–April) as days pass $11$–$13$ hours and mornings warm past $8{}^{\circ}\mathrm{C}$; [leaves](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) gild and drop (October–November) as days shorten and mornings chill. Tree events pair with condition changes frame after frame.

**10.** The patch did not die: it withdrew to storage — alive as [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber) below the same spot. “Gone” always deserves: gone *where*, as *what*?

**11.** Bare [branches](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-tree) carrying [buds](#def-g6-life-through-seasons-buds); a magpie likely somewhere; below, [leaf](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) litter and bare daffodil ground hiding [bulbs](https://one-course.com/books/biology/1/en/chapter/24-plants-without-seeds#ex-g4-plants-without-seeds-bulbtuber); poppy [seeds](https://one-course.com/books/biology/1/en/chapter/16-flowers-fruits-and-seeds#prop-g3-flowers-fruits-seeds-transform) in the path’s earth. The certain bets are the [buds](#def-g6-life-through-seasons-buds) and the bareness — they follow from the tree’s [deciduous](#def-g6-life-through-seasons-trees) machinery and one year’s proof; the magpie is probable, not promised.

**12.** It shows warmth was the missing condition — [light](https://one-course.com/books/biology/1/en/chapter/37-exploring-our-environment#def-g6-exploring-our-environment-conditions) indoors in February is no longer than outdoors, but the water and room are warm, and that sufficed. Fair test: two twigs from the same tree, both in water at the same window, one in a warm room, one in a cold porch — one difference, warmth; if only the warm twig [leafs](https://one-course.com/books/biology/1/en/chapter/3-plants-around-us#def-g1-plants-around-us-parts) out, the verdict is nailed.