BT101 Quiz

MUHAMMAD IMRAN BT 101 - Ecology, Biodiversity & Evolution-I

PAST PAPER QUESTIONS SOLVED

FINAL TERM

Q1. Trophic Level?

Trophic Level • Trophic level of an organism is position it occupies in a food chain. (PPTS) The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. (Internet)

Q2. Ecological niche?

• Each organism in a community confronts the challenge of survival in a different way. • Occupies a specific functional role and place called its niche. • The niche an organism occupies is the total of all the ways it uses the resources of its environment.

A niche may be described in terms of: • Space utilization • Food consumption • Temperature range • Appropriate conditions for mating • Requirements for moisture • Other factors. (PPTS)

Q3. Trichocyst?

Trichocysts are pellicular structures primarily used for protection. • They are rodlike or oval organelles • Oriented perpendicular to the plasma membrane • Pellicle can discharge trichocysts, which then remain connected to the body by a sticky thread.

Q4. Adaptedness or Fitness? Explain Adaptedness?

Adaptedness or fitness: is a measure of the capacity for successful reproduction in a given environment. • Not every characteristic is an adaptation to some kind of environmental situation. • Neither adaptations lead to perfection.

Q5. Source of land pollution?

Pollution Classified as: 1. Point source 2. Non point source 1. Point source Single identifiable source of pollution Example: • Land fill • Factory drain • Sewages pipes Non Point source Resulting from many diffuse sources Example: • Sediment • Nutrients • Toxic contaminants and chemicals • Pathogens

Q6. Logistic population growth?

Logistic population growth occurs when the growth rate decreases as the population reaches carrying capacity. Carrying capacity is the maximum number of individuals in a population that the environment can support.

Q7. Types of Genetics drift?

There are two major types of genetic drift: population bottlenecks and the founder effect. A population bottleneck is when a population's size becomes very small very quickly. This is usually due to a catastrophic environmental event, hunting a species to near extinction, or habitat destruction.

Q8. How natural selection work in evolution?

The mechanism that Darwin proposed for evolution is natural selection. Because resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations.

Q9. R selected organism?

• High growth rates • Typically exploit less crowded ecological habitats • Produce many offspring • Relatively low probability of surviving to adulthood • High reproductive rate supports their survival. • Especially in unstable environment.

Q10. Ozone depleting substance?

Ozone depleting substances

include:

•  chlorofluorocarbons

(CFCs) hydrochlorofluorocarbons (HCFCs) hydrobromoflurocarbons (HBFCs) halons. methyl bromide. carbon tetrachloride.  methyl chloroform.

Q11. Nematode characteristic?

Their body is bilaterally symmetrical and triploblastic. They are cylindrical in shape. They exhibit tissue level organization. Their body has a cavity or pseudocoelom. The alimentary canal is distinct, with the mouth and the anus. They are sexually dimorphic. (Internet)

Q12. Food chain?

A food chain is a linear network of links in a food web starting from producer organisms and ending at apex predator species, detritivores, or decomposer species. A food chain also shows how the organisms are related with each other by the food they eat. Each level of a food chain represents a different trophic level.

Q13. Endomembrane system?

What is the endomembrane system? The endomembrane system (endo- = “within”) is a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins.

Q14. Primary productivity of wetland?

In general, swamps and marshes have the highest

primary

production of all the world's ecosystems. Primary production of all wetland types varies from 600-2000 gC/m2/y. ... So wetlands that are stagnant are less productive than those that flow or are open to flooding rivers.

Q12. Tropical rainforest ecosystem?

The tropical rainforest biome has four main characteristics: very high annual rainfall, high average temperatures, nutrient-poor soil, and high levels of biodiversity (species richness). ... Tropical rainforests also have high humidity; about 88% during the wet season and approximately 77% in the dry season.

Q15. Bio magnification?

Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain.

Q16. Phyletic gradualism?

Evolutionary changes are occurring gradually over millions of years. • This concept, called phyletic gradualism.

Q17. Acid rain?

rainfall made so acidic by atmospheric pollution that it causes environmental harm, chiefly to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulphur and nitrogen oxides which combine with atmospheric water to form acids.

Q18. How global warming contribute to destroy evolution?

Increasing global temperature means that ecosystems will change; some species are being forced out of their habitats (possibly to extinction) because of changing conditions, while others are flourishing. Secondary effects of global warming, such as lessened snow cover, rising sea levels, and weather changes.

Q19. Which factor is limit to population size and growth?

Limiting factors regulate population size • Rate of Birth • Rate of Death/mortality • Dispersal • Food Resources • Space to grow • Environmental factors

Q20. Consumer resources ecosystem?

Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator (see predation), host-parasite, plant-herbivore and victim-exploiter systems.

Q21. Characteristic of bacteria?

Bacteria are like eukaryotic cells in that they have cytoplasm, ribosomes, and a plasma membrane. Features that distinguish a bacterial cell from a eukaryotic cell include the circular DNA of the nucleoid, the lack of membranebound organelles, the cell wall of peptidoglycan, and flagella.

Q22. Speices and Soecution?

• Species is a group of populations in which genes are actually, or potentially, exchanged through interbreeding. • This definition has problems. • Taxonomists depend upon: 1. Morphological 2. Ecological information • Especially in case of fossils

Speciation • Formation of new species. • A requirement of speciation is that subpopulations are prevented from interbreeding. • This is called reproductive isolation. • No gene flow in case of reproductive isolation.

23. Way of reproductive

isolation?

Ways of ReproductiveIsolation

1. Premating isolation • Geographical Isolation - prevents mating from taking place • Barriers, such as rivers or mountain ranges, may separate subpopulations
2. Postmating isolation • Prevents successful fertilization and development • Even though mating may have occurred.

Q24. Energy in ecosystem?

The largest source of energy for an ecosystem is the sun. Energy that is not used in an ecosystem is eventually lost as heat. Energy and nutrients are passed around through the food chain, when one organism eats another organism. Any energy remaining in a dead organism is consumed by decomposers. (Internet)

Q25. Cell of porifera?

Sponges have several cell types: * Choanocytes (also known as "collar cells"), flagellated cells which function as the sponge's digestive system, are remarkably similar to the protistan choanoflagellates. The collars are composed of microvilli and are used to filter particles out of the water. (Internet)

Q26. Class of arthopoda?

There are 5 major classes of arthropods. Insects, centipedes, millipedes, arachnids and crustaceans. They all have their own characteristics to belong in that particular class. (Internet)

Q27. Origin eukaryotic?

The origin of the eukaryotic cell is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The timing of this series of events is hard to determine; Knoll (2006) suggests they developed approximately 1.6–2.1 billion years ago. (Internet)