BT101 Midterm Solved Subjective

BT 101 Mid term question Dec2017

1: Write short note on population dispersion ?5 The ways in which populations are spread across Earth has an effect on the environment. Developing countries tend to have higher birth rates due to poverty and lower access to family planning and education, while developed countries have lower birth rates. In 2015, 80 per cent of the world’s populations live in less-developed nations. These faster-growing populations can add pressure to local environments

The Three Main Types of Population

Dispersion

Population dispersion is the observation of where individuals are found in a habitat. How individuals "disperse" themselves. There are three main types of dispersion: clumped, uniform and random.

Clumped Dispersion

Is the tendency for populations to be found in tight clusters, dispersed across a large landscape. In between these population hubs, very few to no individuals are usually found. This sort of a dispersion can be caused by a number of factors. Some species cluster together for protection, while others group around natural resources necessary to their survival.

Is the tendency for populations to be found evenly distributed about their habitat. This is generally caused by a species ability to

Is the tendency for populations to be found randomly about their habitat. In immobile species, this is usually caused by their ability to live anywhere in a given habitat, except, they are limited to growing wherever they are first set root (which is usually caused randomly, from spores drifting in the wind to seeds falling and tumbling on the ground). In motile populations, individuals are able to move about their habitat, so that at any given instance, they can be found anywhere about their environment.

2: Write short note on Soil horizone?5 >A vertical section of soil that tells about various layers of the soils as zones. These zones are named as soil horizons. In a typical soil profile, four zones are exposed,

1. >O-horizon · 2. A-horizon · 3. B-horizon · 4. C-horizon · >O-horizon

Uppermost zone of soil surface where fallen leaves and other plant matter is deposited. A-horizon Zone of leaching because percolating rain picks up the soluble materials and transport it downward to B-horizon

>B-horizon

Zone of accumulation because all the leaching materials are accumulated in horizon.

C-horizon

it is composed of broken bedrock material that is merged with underlying solid and hard bedrock material. > Factors that influence these horizons are,

▪ Erosion

▪ Wind

▪ Precipitation · ▪ Human activity · ▪ Topography

3: Differentiate between Autogenic and Allugenic succession?3

>Autogenic succession · In autogenic succession the successional process · is controlled by living or biotic component of · an · ecosystem · Allogenic succession · The entire successional process is controlled · by · non living or abiotic components of

ecosystem.

4: differniate between population and meta polutaion ?3

Metapopulation · A group of populations of same species which · are separated by space. Individuals can move · from one population to other. Extinction and · colonization are the main processes that

regulate the Metapopulation. In biology, a population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding.

5 : HAB stands for?2 HAB. Harmful Algal Bloom. 6: how to analysia the kind of soil ?2

7. Define food pyramid? 2)

>A food pyramid is a graphical representation

of flow of energy through different trophic

levels of an ecosystem.

The highest level an organism occupies on a

food chain is termed as trophic level.

8. Difine species hotspotes?3)

Species hotspots

Species hotspots are geographic regions that

support high level of species diversity.

Tropical rainforests are one of important

species hotspots region in the world because

they are home to more than 50% species.

Q9. population dispersion??

Above question 1

10. difference between aquatic and

trestrail biomes? Almost all the habitats found in the world can be put into two major habitats; aquatic and terrestrial. Aquatic ecosystems are found in water .Terrestrial animals are the animals who live on land for most or all of their life span. 11. mechanism of survival of endothermic cold and hot environment?

Q12. define atmosphere and role in ecosystem?

An atmosphere (from Greek ἀτμός (atmos), meaning "vapor", and σφαῖρα (sphaira), meaning "sphere") is a layer of gases surrounding a planet or other material body, that is held in place by the gravity of that body. Role

The role of the atmosphere in the provision of ecosystem services. Cooter EJ1, Rea A, Bruins R, Schwede D, Dennis R.

Author information

Abstract

Solving the environmental problems that we are facing today requires holistic approaches to analysis and decision making that include social and economic aspects. The concept of ecosystem services, defined as the benefits people obtain from ecosystems, is one potential tool to perform such assessments. The objective of this paper is to demonstrate the need for an integrated approach that explicitly includes the contribution of atmospheric processes and functions to the quantification of air-ecosystem services. First, final and intermediate airecosystem services are defined. Next, an ecological production function for clean and clear air is described, and its numerical counterpart (the Community Multiscale Air Quality model) is introduced. An illustrative numerical example is developed that simulates potential changes in air-ecosystem services associated with the conversion of evergreen forest land in Mississippi, Alabama and Georgia to commercial crop land. This one-atmosphere approach captures a broad range of service increases and decreases. Results for the forest to cropland conversion scenario suggest that although such change could lead to increased biomass (food) production services, there could also be coincident, seasonally variable decreases in clean and clear air-ecosystem services (i.e., increased levels of ozone and particulate matter) associated with increased fertilizer application. Metrics that support the quantification of these regional airecosystem changes require regional ecosystem production functions that fully integrate biotic as well as abiotic components of terrestrial ecosystems, and do so on finer temporal scales than are used for the assessment of most ecosystem services.

13. Keystone species and foundation

species with examples.

• Some species play a key and crucial role · in maintaining the structure of a · biological community. They are called · Keystone species because they have a · large · effect · on · the · types · and · abundances of other species in an · ecosystem. Sharks are also a keystone · species because they remove injured · and sick animals from the ocean, and

thus play an important ecological role.

>Foundation species, plays a major role in

shaping

communities.

They create and Enhance the habitats in · ways that · provides benefits to other species. They · facilitate · the survival and reproduction of other · species in

the community.

>For example, elephants push over, break, or · uproot trees, creating · forest openings in the grasslands and

woodlands of Africa.

>Foundation vs keystone species · • A foundation species creates or provide · a foundation of an ecosystem while · keystone · species · regulates · and maintains that ecosystem

14. Generalists and specialist species. • Those species that have broad range of niches are known as generalist species. Flies, cockroaches, mice, rats, white-tailed deer, raccoons, and humans are Generalist species

• Those species that occupy narrow range of niches

are known as specialist species. For example, tiger salamanders breed only in fishless ponds where their larvae will not be eaten. Some shorebirds occupy specialized niches, feeding on crustaceans, insects,

and

other organisms on sandy beaches and their adjoining coastal wetlands.

Q15. How can we analyse any kind of soil?

Soil type usually refers to the different sizes of mineral particles in a particular sample. Soil is made up in part of finely ground rock particles, grouped according to size as sand and silt in addition to clay, organic material such as decomposed plant matter. Each component, and their size, plays an important role. For example, the largest particles, sand, determine aeration and drainage characteristics, while the tiniest, sub-microscopic clay particles and are chemically active, binding with water and plantnutrients. The ratio of these sizes determines soil type: clay, loam, clay-loam, silt-loam, and so on.