Environmental Science Midterm

Reviewer for midterms

What is a biome?

A large terrestrial environment characterized by similar plants, animals, climate, and soil types.

What does each biome contain?

Different ecosystems that interact and affect one another.

What are the major biomes?

Desert, Grasslands/Prairies, Forests, Taiga, Tundra, Savannah.

Describe the desert biome.

Dry, uninhabited, uncultivated (e.g., Middle East).

Describe the grassland/prairie biome.

Deep fertile soil, tall coarse grasses (e.g., Central USA).

Describe the forest biome.

Covered with trees, precipitation ≥ 75 cm.

Describe the taiga biome.

Also called Boreal Forest or “primeval forest,” with conifers that survive extreme cold.

Describe the tundra biome.

Between Arctic snow and ice; only mosses and low plants grow.

Describe the savannah biome.

Very hot days and cold nights (e.g., Africa).

What are the types of tropical biomes?

Tropical Rainforest, Tropical Seasonal Forest, Tropical Savanna, Tropical Thornwood/Shrubwood.

Describe the tropical rainforest.

High and constant rainfall; high biodiversity.

Describe the tropical seasonal forest (monsoon).

Seasonal rainfall with a pronounced dry season.

Describe the tropical savanna.

Grasslands with scattered small trees like acacias.

Describe the tropical thornwood/shrubwood.

Hot, dry areas with thorny shrubs.

What are the types of temperate biomes?

Temperate Deciduous Forest, Temperate Evergreen Forest, Temperate Rainforest, Temperate Woodland, Temperate Shrubland, Temperate Grassland.

Describe the temperate deciduous forest.

Moderate humidity, year-round rain, cold winters.

Describe the temperate evergreen forest.

Poor soil, droughts, and frequent forest fires.

Describe the temperate rainforest.

Near sea, cold climate, abundant winter rain.

Describe the temperate woodland.

Too dry for full forests; supports trees and grasses.

Describe the temperate shrubland (chaparral).

Dry climate, little or no summer rain.

Describe the temperate grassland.

Known as prairie, steppe, pampas, or veldt; moderate rainfall.

What are environmental variables affecting biomes?

Sunlight, Temperature, Oxygen, Water & dissolved salts, Nutrients, Metabolic waste.

How much of Earth was once covered by rainforests?

About 25 million km² (16% of land surface).

How much rainforest remains today?

Only about 10 million km².

How much forest remains in the Philippines?

About 6 million hectares.

What are the functions of rainforests?

Preserve biodiversity, regulate water flow, recycle carbon globally.

What is the difference between forest and woodland?

Forest: tree crowns form a canopy; Woodland: trees spaced apart, open canopy.

What are causes of rainforest destruction?

Poverty, overpopulation, demand for wood, poor policies, agriculture, industrialization, settlement.

What are the types of forests in the Philippines?

Dipterocarp, Pine, Molave, Beach, Mangrove, Mossy.

Describe the dipterocarp forest.

Most common; source of timber (yakal, apitong, tangile).

Describe the pine forest.

Contains Mindoro Pine and Benguet Pine species.

Describe the molave forest.

Found in Central Luzon.

Describe the beach forest.

Found in coastal areas (dungon, agoho, banulad).

Describe the mangrove forest.

Found in tidal flats; source of charcoal, tannin, firewood.

Describe the mossy forest.

Found in high mountains; home to endemic wildlife.

What are the importance of forests?

Provide food and medicine, prevent soil erosion, control river flow, refresh air, provide lumber and materials.

What is deforestation?

Large-scale removal or permanent destruction of forests.

What are the causes of deforestation?

Logging, kaingin system, cattle ranching, mining, housing, roads, industrial development, agriculture, dam construction.

What are natural causes of deforestation?

Forest fires, volcanic eruptions, typhoons.

What are the effects of deforestation?

Soil erosion, flooding, water shortage, greenhouse effect.

What are methods of reforestation?

Natural reseeding, seeding by foresters, and planting young trees.

What is natural reseeding?

Seeds dispersed naturally by wind, birds, or water.

What is seeding by foresters?

Mechanical or aerial seeding with fertilizers and herbicides.

What is direct planting?

Planting of young trees from nurseries.

How does rapid population growth affect society?

It burdens food, health, education, and employment systems.

What are the layers of the Earth?

Crust, Mantle, Core.

What is the mantle?

The thickest layer, about 80% of Earth's volume.

What is the core?

The innermost region of the Earth.

What is the crust?

The thin outer layer made of low-density rocks.

What are the Earth's four spheres?

Atmosphere, Lithosphere, Hydrosphere, Biosphere.

What is the atmosphere?

Layer of gases (78% nitrogen, 21% oxygen, 1% other gases).

What is the lithosphere?

Earth’s solid crust and upper mantle.

What is the hydrosphere?

All water on Earth.

What is the biosphere?

The zone where life exists on Earth.

What is an open system?

System that exchanges energy and matter with surroundings.

What is a closed system?

Self-contained system (e.g., Earth's air, water, and resources).

What are the levels of ecological organization?

Organism, Population, Community, Ecosystem, Biosphere.

Define population in ecology.

Group of same species living in one area.

Define community in ecology.

All different organisms living in one area.

Define ecosystem.

Interaction between organisms and their environment.

Define biosphere.

The world of living things on Earth.

What are characteristics of population?

Size, Density, and Distribution.

What factors affect population size?

Natality, Mortality, Immigration, Emigration.

What are the types of population distribution?

Random, Uniform, Clumped.

What was the population of the Philippines in 1995?

68.6 million.

What was the population of the Philippines in 2020?

109.5 million.

What is the population growth rate of the Philippines?

About 2.1–2.3% yearly.

How many Philippine islands are populated?

Only about 1,000 of 7,107 islands.

What region is the most populated in the Philippines?

NCR, with 15,617 persons per km².

What are reasons for high population growth?

Big families, gender roles, poor family relationships, economic reasons, low education, religion.

What other factors increase population?

Medical advances, industrialization, lack of family planning.

What are the effects of overpopulation?

Food shortage, pollution, crime, unemployment, poor health and education, moral decline, environmental damage.

What is Earth's carrying capacity?

The maximum number of organisms an environment can support based on food, space, and resources.

What are humans classified as in terms of nutrition?

Heterotrophs; they depend on other organisms for food.

What is starvation?

Death caused by lack of food.

What is malnourishment?

Lack of essential nutrients needed by the body.

What links hunger and poverty?

Poverty and unequal food access; rural poor often ignored by government.

What are macronutrients?

Nutrients needed in large amounts: carbohydrates, proteins, and fats.

What is the main function of carbohydrates?

Provide 60% of body energy needs.

What is the function of proteins?

Build and repair tissues; 20% of diet.

What is the function of fats/lipids?

Provide energy storage and insulation; 20% of diet.

What is marasmus?

Protein and calorie deficiency causing a thin, weak body.

What is kwashiorkor?

Protein deficiency causing swollen belly and discolored hair/skin.

What are the 10 essential amino acids?

Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine.

What are micronutrients?

Nutrients needed in small amounts: minerals and vitamins.

Give examples of important minerals.

Calcium (bones), Iron (blood), Iodine (thyroid).

What are vitamins?

Organic compounds essential for body function.

What are the main food groups?

Milk & milk products, Meat/Fish/Poultry, Vegetables & Fruits, Bread & Cereals.

What is the importance of milk and milk products?

Complete food rich in protein and calcium.

What is the importance of meat, fish, and poultry?

Sources of protein.

What is the importance of vegetables and fruits?

Sources of vitamins and minerals.

What is the importance of bread and cereals?

Sources of carbohydrates and energy.

What are food additives?

Substances used as flavor enhancers, preservatives, and colorings.

Give examples of food additives.

MSG, Sodium nitrate, Benzoic acid, BHT.

What is "Chinese restaurant syndrome"?

Burning or pressure feeling from excessive MSG intake.

What is salitre (sodium nitrate) and its effect?

Preservative that can be a possible carcinogen.