Weather, Climate and Animal Adaptation - Class 7 Notes & Olympiad Questions

Weather

a) Weather refers to the daily conditions of the atmosphere in a particular location, including factors such as temperature, humidity, rainfall, wind speed, and wind direction. It is important to note that weather can vary from day to day and can change rapidly. For instance, a day may start with sunshine but later experience rain.
b) Weather reports typically provide information about the maximum and minimum temperatures for the day. The minimum temperature is usually observed in the early morning, while the maximum temperature is experienced in the afternoon. These temperatures are measured using specialised thermometers known as minimum and maximum thermometers.
c) Humidity, which refers to the amount of water vapour present in the air, is measured using a device called a hygrometer. It helps determine how moist or dry the atmosphere is.
d) Rainfall is measured using a rain gauge, which collects and measures the amount of precipitation in a specific area over a given period.
e) The changes in weather are primarily influenced by the Sun, which emits significant amounts of heat and light energy onto the Earth. These energy inputs contribute to the formation of winds, the occurrence of rainfall, and the transitions between different seasons.
f) So, the weather is a fascinating and ever-changing part of our everyday lives. It's influenced by various factors and can impact our activities, clothing choices, and overall experience of the outdoors.

Climate

a) Climate refers to the long-term average weather conditions of a particular place. It is determined by analysing weather patterns over an extended period, typically spanning at least 25 years.
b) Unlike the weather, which can change daily, the climate provides a broader perspective on the typical conditions experienced in a specific location.
c) The climate of a place can vary from one location to another. Different regions around the world have different climates due to factors such as latitude, altitude, proximity to bodies of water, and atmospheric circulation patterns.
d) For example, if a place consistently experiences high temperatures throughout the year, we describe its climate as hot. This indicates that the region tends to have warmer average temperatures compared to other areas.
e) Similarly, if a location frequently receives heavy rainfall on most days, alongside high temperatures, we would describe its climate as wet and hot. This suggests that the area has a combination of significant precipitation and warm temperatures as a typical weather pattern.
f) Understanding the climate of a place helps us anticipate what kind of weather conditions we can expect in the long term. It provides valuable information for activities such as agriculture, urban planning, and assessing the suitability of an area for certain plants, animals, or human settlements.

Factors Affecting Climate

There are several factors that influence climate. Here are some key factors:

1. Distance from the equator (Latitude)

a) Places closer to the equator receive more direct sunlight throughout the year, resulting in higher temperatures.
b) As you move away from the equator towards the poles, the angle at which the sunlight reaches the Earth's surface decreases, leading to cooler temperatures.

2. Distance from the Sea

a) Proximity to large bodies of water, such as oceans or seas, can moderate the climate of a region.
b) Coastal areas tend to have milder temperatures because water has a higher heat capacity than land.
c) This means that it takes longer for the ocean to heat up or cool down compared to land, resulting in more stable and moderate temperatures near the coast.

3. Wind

a) Wind patterns play a significant role in determining climate. The direction and type of winds (cold or hot, humid or dry) can influence the temperature, moisture levels, and overall climate of a particular region.
b) For example, winds blowing from cooler regions can lower temperatures, while winds carrying moisture from the ocean can increase humidity and precipitation.

4. Humidity

a) The amount of moisture present in the air, known as humidity, affects the climate of a place.
b) Areas with higher humidity tend to feel more uncomfortable and experience more frequent rainfall, while regions with lower humidity may have drier climates.

5. Ocean Currents

a) Ocean currents, like the Gulf Stream or the El Niño-Southern Oscillation (ENSO), can transport heat energy across large distances. These currents can either warm or cool the adjacent coastal areas, impacting the local climate.
b) For example, warm ocean currents can lead to milder winters in coastal regions, while cold ocean currents can result in cooler temperatures.

6. Human Influence

a) Human activities can significantly impact the climate. The release of greenhouse gases, such as carbon dioxide, through the burning of fossil fuels contributes to the greenhouse effect, leading to an increase in global temperatures.
b) Deforestation, urbanisation, and the release of pollutants can also alter local climate patterns.

It's important to note that these factors interact with each other in complex ways, and understanding them helps scientists and researchers study and predict climate changes over time.

Climate and Animal Adaptation

a) Adaptation refers to an organism's remarkable ability to develop specific features that aid its survival in a particular habitat.
b) Animals undergo alterations in their characteristics and behaviours in response to the prevailing climate conditions.
c) These adaptations occur gradually over time through the process of evolution, allowing animals to better cope with their environment and increase their chances of survival.

Polar Regions

a) The Polar Regions are characterised by their extremely cold climate. These areas are predominantly covered in snow throughout most of the year.
b) One unique aspect of these regions is the phenomenon of polar nights and days. For six months, the sun remains above the horizon, resulting in continuous daylight. Conversely, during the other six months, the sun remains below the horizon, leading to an extended period of darkness.
c) In winter, temperatures can plummet as low as −37°C, making survival a formidable challenge for both wildlife and humans in these icy landscapes.

Adaptations of Polar Bear

Polar bears have developed remarkable adaptations to thrive in the harsh Arctic environment:

Insulation: Polar bears have two thick layers of fur and a layer of fat beneath their skin. These natural insulators provide excellent warmth and protection against the freezing temperatures of their habitat.

Sharp Sense of Smell: With their keen sense of smell, polar bears can easily detect and track their prey, even from great distances. This remarkable ability helps them locate and capture their food sources, such as seals, ensuring their survival.

Versatile Paws and Claws: Equipped with wide, large paws and long, curved, and sharp claws, polar bears are well-adapted for their icy surroundings. These specialised features aid them in both swimming through Arctic waters and walking on slippery ice surfaces.

Camouflage: The polar bear's white fur provides excellent camouflage in snowy landscapes. This adaptation helps them blend seamlessly into their surroundings, making it easier to approach prey or remain undetected by potential threats.

Heat Regulation: Despite their white fur, the polar bear's skin underneath is actually black. This unexpected adaptation enhances their heat retention capacity by absorbing and retaining heat from the sun's rays, aiding their survival in freezing conditions.

Adaptations of Penguins

Penguins have developed remarkable adaptations that allow them to thrive in their icy and aquatic environments:

Insulating Features: Penguins possess thick skin with high-fat content, providing them with insulation against the cold temperatures of their habitat. Additionally, their dense feather cover acts as a protective layer, further enhancing their insulation and helping to retain body heat.

Cooperative Huddling: Penguins are highly social creatures that rely on each other for warmth. When temperatures drop, they gather in large groups and huddle together. By tightly packing together, they reduce heat loss and collectively maintain a warmer microclimate within the huddle.

Streamlined Body and Webbed Feet: Penguins have streamlined bodies and webbed feet, perfectly adapted for their life in the water. These features enable them to swim with agility and efficiency, allowing them to navigate the ocean swiftly in search of food.

Waterproof Feathers: Penguin feathers are specially designed to be waterproof. This adaptation is vital for their survival, as it allows them to remain dry while diving and swimming in cold waters. The waterproofing feature prevents their feathers from becoming waterlogged, ensuring their buoyancy and helping them swim faster and with greater ease.

Migratory Birds in the Polar Region

a) Birds such as the Siberian crane and Arctic tern have adopted a fascinating strategy to cope with the extreme cold of polar region winters. They undertake long-distance migrations, departing from their breeding areas and flying towards warmer regions.
b) This migration allows them to escape the frigid temperatures and scarcity of food in the polar regions during the winter season.
c) These migratory birds journey to more hospitable habitats, where they can find milder climates and abundant food sources. They spend the winter months in these warmer regions, taking advantage of the favourable conditions for survival and reproduction.

Tropical Rainforests

a) Tropical rainforests, found near the equator, have a hot climate due to their location.
b) The temperatures in these regions can soar as high as 40°C and rarely dip below 15°C.
c) Day and night durations remain almost equal all year round, providing a balanced light-dark cycle.
d) These rainforests receive abundant rainfall, resulting in a hot and humid climate. The combination of high temperatures and ample moisture creates a lush environment with thriving plant and animal life.
e) One fascinating aspect of tropical rainforests is the adaptation of many animals to live in trees.
f) Animals in tropical rainforests have evolved to make the most of the abundant resources found in the treetops.

Some adaptations and examples of animals living in the tropical rainforest are:

Camouflage

a) Many animals in the rainforest have developed camouflage to blend in with their surroundings, making it harder for predators or prey to spot them.
b) Examples include the leaf-tailed gecko, which has a body shape and colouration that resembles a leaf, and the jaguar, which has a spotted coat that helps it blend into the dappled sunlight of the forest.

Arboreal Adaptations

a) The dense trees of the rainforest have led to adaptations in animals that allow them to live in the treetops.
b) For example, the spider monkey has long limbs and a prehensile tail, which help it swing from branch to branch with agility.
c) Another example is the sloth, which has long claws and specialised muscles that allow it to hang upside down and move slowly through the trees.

Canopy Dwellers

a) Some animals have adapted to live primarily in the uppermost layer of the rainforest, called the canopy. These animals have unique features, such as strong beaks and sharp claws, that allow them to move and forage in this aerial habitat.
b) Examples include toucans, which have large, colourful beaks for feeding on fruits, and tree-dwelling frogs, like the red-eyed tree frog, which have suction cup-like toe pads for clinging to leaves and branches.

Symbiotic Relationships

a) Many animals in the rainforest form symbiotic relationships, where different species rely on each other for survival.
b) For example, the relationship between certain ants and acacia trees is mutualistic. The ants live inside the tree and protect it from herbivores, while the tree provides the ants with food and shelter.

Poisonous Defenses

a) Due to high competition and predation in the rainforest, some animals have developed venomous or poisonous defences.
b) The poison dart frog, for instance, carries toxins in its skin, deterring predators from eating it. Similarly, the venomous bushmaster snake uses its venom to subdue prey and defend itself.

Desert

a) Deserts are challenging places to live due to their extreme conditions. The days are very hot while the nights can be freezing cold.
b) Rainfall is scarce, making the desert a dry and arid environment. Surviving in these conditions requires special adaptations.
c) Desert plants have developed long roots to find water deep underground, or they have unique ways to store and conserve water.
d) Desert animals have also adapted to these tough conditions by being active at night to avoid the intense heat, and some have special features to minimise water loss.
e) Despite the harshness, deserts are home to fascinating and resilient plants and animals that have found remarkable ways to thrive in these challenging environments.

Some adaptations and examples of animals living in the desert are:

Water Conservation

a) Desert animals have adapted to conserve water efficiently due to the scarcity of water in their environment. They have the ability to extract and retain moisture from their food or reduce water loss through specialized mechanisms.
b) Examples include the kangaroo rat, which can survive without drinking water by extracting moisture from the seeds it consumes, and the dromedary camel, which can go long periods without water by conserving it through concentrated urine and minimal sweating.
c) Desert tortoise has the capacity to store water in its bladder. Additionally, it can endure extended periods without food or water.
d) Birds and reptiles in the desert have developed adaptations to conserve water. Instead of excreting liquid urine like mammals, they excrete metabolic waste in the form of uric acid, which is a white, insoluble compound.

Nocturnal Lifestyle

a) Many desert animals are nocturnal, meaning they are active during the cooler nighttime hours to avoid the scorching heat of the day.
b) Nocturnal behaviour helps them conserve energy and minimize water loss.
c) Examples include the desert fox, which hunts at night to avoid extreme temperatures, and the jerboa, a small hopping rodent that is adapted to the cooler nighttime environment.

Burrowing Adaptations

a) Burrowing is a common adaptation among desert animals to escape extreme temperatures and reduce water loss.
b) These animals create underground burrows that provide shelter from the heat and help maintain a more stable temperature and humidity.
c) Examples include the fennec fox, which digs burrows to escape the heat and rest during the day, and the desert tortoise, which creates burrows to escape temperature extremes and conserve water.

Heat Tolerance

a) Desert animals have developed various adaptations to withstand high temperatures. They may have light-coloured or reflective scales or feathers to reflect sunlight and reduce heat absorption, or they may have large ears or elongated limbs to increase surface area for heat dissipation.
b) The thorny devil, a lizard found in Australian deserts, has specialized scales that help it cool down by trapping moisture from the air.

Efficient Movement

a) Desert animals often have adaptations that allow them to move efficiently across sandy or rocky terrain.
b) These adaptations include long legs for fast running or hopping, specialized feet for walking on sand, and even the ability to travel long distances without needing much water.
c) Examples include the roadrunner, known for its quick running speed, and the sidewinder snake, which moves in a sideways motion to navigate the loose sand.

Adaptation of Camels

a) The camel is a well-known animal adapted to desert conditions and is often referred to as the "ship of the desert."
b) Camels have several adaptations that allow them to thrive in arid environments. They can withstand high temperatures and go for long periods without drinking water due to their ability to conserve water.
c) Their humps store fat, not water, which provides energy when food and water are scarce.
d) Camels also have specialized nostrils and eyelashes to protect against sand, and their broad, tough feet help them walk on hot sand without sinking.