Diversity in the Living World · Lesson 5 of 7
How Living Things Fit Their Surroundings
“Connect the features of plants and animals with the conditions of the places where they live.”
• Compare living things found in deserts, mountains, oceans, and forests. • Explain an adaptation by linking a feature with a survival challenge. • Describe adaptations of cactus, deodar, camels, rhododendrons, and fish. • Explain habitat as a place that provides resources and suitable conditions. • Distinguish an adaptation from a claim that an individual changes whenever it needs to.
Different surroundings, different challenges
A goat moving across grass and a fish swimming through water face different surroundings. Legs support the goat on the ground, while a fish’s body, tail, and fins help it move in water. Plants face different challenges too: water may be scarce in a desert, while snow and cold affect some mountain regions. Connecting a feature with its surroundings helps us understand why living things differ from place to place.
Start by comparing places before explaining their living things. A hot desert may have very little available water and large differences between daytime and night-time temperatures. High mountain areas can be cold and snowy, though conditions vary with location and height. An ocean is a large aquatic environment. Forest conditions also vary, but trees and other vegetation provide many living places and resources.
| Region | Example living things | Condition to investigate |
|---|---|---|
| Hot desert | Camel, cactus | Scarce water; sandy ground; heat |
| Cold desert or mountains | Cold-desert camel, deodar | Cold; limited food at some times; snow in suitable mountain areas |
| Ocean | Fish, whales, sea turtles | Water surrounding the animal |
| Forest | Many trees, insects, birds; lions in suitable forest regions | Vegetation, food, shelter, and local climate |
Make a table with columns for desert, mountains, ocean, forest, and a local region. Add named plants and animals you know from reliable observations or references. Then write a relevant condition for each place. The task investigates how surroundings differ; do not assume an animal lives in every location with the same broad label.
A feature that helps a living thing survive in its usual surroundings. To explain an adaptation, link the feature to the condition or challenge it helps meet.
Water storage and shedding snow
A cactus has a thick, fleshy stem that can store water. Stored water helps it survive periods when little water is available from the surroundings. Merely saying “cactus is a desert plant” identifies a place; explaining its fleshy stem connects structure with a survival need. The helpful reasoning is condition, feature, then benefit.
Deodar trees in snowy mountain regions have a roughly conical form and sloping branches. Snow can slide from these branches more readily than from a broad flat surface. Flexible branches also help deal with snow loads. This reduces the burden of snow on the tree. Not every mountain plant has the same form: the explanation concerns this tree and the particular challenge being considered.
Problem
Why is “a cactus has a thick stem” incomplete as an adaptation explanation?
- 1.Name the environmental challenge: water may be scarce.
- 2.Identify what the feature does: the fleshy stem stores water.
- 3.Connect the two: stored water helps the cactus survive dry periods. The feature has now been linked to a benefit.
Camels in hot and cold deserts
Deserts are defined by very low rainfall, so they need not all be hot. The camel commonly seen in Rajasthan has one hump, long legs, and broad padded feet. The broad feet spread the animal’s weight over sand, reducing sinking. Its long legs keep much of the body higher above the hot ground. The underside of the foot is a broad pad; the toes also bear nails.
Cold-desert camels seen in Ladakh commonly have two humps and a thicker coat, with conspicuous long hair around the head and neck. Their legs are comparatively shorter than those of the hot-desert camel. The thick hair helps reduce heat loss in cold conditions. Both camels are suited to their usual environments, but the contrast shows why “desert adaptation” does not mean one identical set of features everywhere.
| Feature | Hot-desert camel | Cold-desert camel | Connection to conditions |
|---|---|---|---|
| Humps | Usually one | Usually two | Fat reserves help when food is scarce |
| Coat | Less heavy than the winter coat of a cold-desert camel | Thick winter coat; long hair around head and neck | Insulation is especially useful in cold |
| Legs | Relatively long | Comparatively shorter | Different overall forms suit different usual conditions |
| Feet | Broad padded feet | Broad feet also useful on the ground | A broad contact area reduces sinking on loose surfaces |
A camel’s hump stores fat, an energy reserve. It does not contain a tank of drinking water or a pile of undigested food. When food is scarce, the animal can use stored fat, and a hump may become smaller. Cold-desert camels may use these reserves through periods of limited winter food.
Camels conserve water in several ways. Their urine can be concentrated and their dung relatively dry, reducing water lost from the body. They tolerate changes in body temperature that help reduce the need for cooling by sweating, but they can sweat when necessary. These features help them go for periods without drinking; they still require water.
Do not explain a camel’s survival by saying its hump stores drinking water. It stores fat. Also, conserving water does not mean never losing water or never sweating. Keep the explanations linked to the actual features.
Problem
A cold-desert camel’s hump becomes smaller during a period with little food. What explanation fits?
- 1.The hump contains fat reserves rather than drinking water.
- 2.The animal can use these energy reserves when food is scarce.
- 3.Using some stored fat can reduce the hump’s size. A change in size is therefore consistent with using reserves.
Wind, water, and body shape
Rhododendrons show that even related plants can have different forms in different regions. In exposed parts of the Nilgiri hills, shorter plants with smaller leaves can withstand strong winds more readily. Rhododendrons in parts of Sikkim may grow taller under different local conditions. Compare the actual conditions rather than assuming that all mountains are the same.
Many fish have streamlined bodies: a smooth overall shape that tapers and allows water to flow around the body readily. This reduces resistance during swimming. Their fins help with control and balance, while movements of the body and tail often provide much of the forward push. A streamlined shape and movement structures work together; the shape alone does not explain the whole swimming action.
Problem
How would you explain why a streamlined body is useful to a swimming fish?
- 1.Identify the surrounding medium: the fish moves through water.
- 2.A smoothly tapering shape lets water flow around it with less resistance than a blunt, broad shape.
- 3.This helps movement through water, together with the body, tail, and fins used during swimming.
Habitat connects features with needs
The surroundings of a living thing provide more than a surface to move on. Food or other resources, water, air, shelter, and suitable conditions all matter. The place where a living thing normally lives is its habitat. An ocean is the habitat of many sea turtles and fish; mountains support suitable rhododendrons, and deserts support camels and other adapted living things.
The place where a living thing lives, with resources and conditions that support its survival.
Many kinds of living things may share a habitat while using different parts of it. A forest tree, a ground insect, and a bird in the branches can live in the same broad habitat without doing the same things. Differences in habitats and in the ability of living things to survive there help explain regional biodiversity.
An animal does not grow a useful body feature immediately because it wants to survive in a new place. Here we describe features already present in living things that help them in their usual habitats. Moving a fish onto land does not give it a goat’s legs or allow it to survive there.
Quiz
Which explanation links feature, condition, and benefit?
What is stored in a camel’s hump?
Which feature is especially helpful for a camel in cold winters?
How can a conical form help deodar in snowy regions?
What is a habitat?
Practice Problems
- Use the sequence condition → feature → benefit to explain a cactus stem, deodar branches, and a fish’s streamlined body.
- Compare hot- and cold-desert camels by humps, coat, and relative leg length.
- Explain why broad padded feet are useful on sand and why a hump is not a water tank.
- Rhododendrons differ in exposed Nilgiri hills and parts of Sikkim. What environmental information should you compare before explaining the difference?
- A learner says camels never sweat and do not need water. Correct both statements using the idea of water conservation.
- List resources and conditions supplied by a pond habitat. Explain why the word habitat means more than a place name.
- Compare a mountain goat with a plains goat using a clear photograph: note shared features and visible differences such as coat. Link a thicker coat to cold without assuming every difference has the same explanation.
Key Takeaways
• Regional conditions help explain differences in biodiversity. • Explain an adaptation by linking a feature with a survival challenge. • Cactus stems store water; deodar forms help shed snow; streamlined fish bodies reduce resistance. • Camel humps store fat, broad padded feet help on sand, and cold-desert coats provide insulation. • Habitat includes the resources and conditions of the place where a living thing lives.