Biology: Topic-wise Test- 6 - NEET MCQ

Hardy-Weinberg equilibrium cannot be disturbed by vegetative propagation as the all new offspring are clone of each other having same gene. Migration, genetic drift, mutation and natural selection affect the equilibrium of alleles in a population.

Uric acid is  less toxic than ammonia or urea. It contains four nitrogen atoms; only a small amount of water is needed for its excretion. Out of solute, it precipitates and forms crystals.

Detailed Explanation:

Option A is wrong because Urea moves to the blood and gets filtered and eliminated with water in urine via the kidneys.

Option B is correct Uric acid is insoluble in water as there are in solid form, thus, containing the least water.
In birds, uric acid mixes with undigested food to form the bird dropping.

Option C is wrong because Ammonia is very toxic and needs water for diffusion.

Option D is wrong because none of the above options has the same toxicity level. 

Hence Option B is correct.

The pyramid of biomass in an aquatic system is always inverted. A sharp decrease in biomass results in inverted pyramids.

• At a constant temperature, soil moisture content shows a parabolic affect on decomposition rates with a maximum rate at intermediate levels of moisture.
• High moisture content limits soil gas exchange leading to low oxygen concentrations and potentially anaerobic conditions.
• At low moisture content, the lack of water limits microbial metabolism; however, many microorganisms can remain active to much lower soil water potentials (at -3.0 MPa) than plants (at -1.5 MPa).

Formula = the rate of change in population size) = (the contribution of each individual to population growth) x (the number of individuals in the population

Process of evolution of different species in a given area starting from a point and radiating to another area of geography (habitats) is called adaptive radiation.  Example : Darwinian finches and Australian marsupials.

Net primary productivity (NPP) is equal to Gross primary productivity (GPP) minus Respiration loss (R). NPP is the available biomass for the consumption of heterotrophs in the ecosystem.

Interactions between different species living within a particular area may be useful as in case of mutualism, fatal as in case of parasitism or neutralin which no one is harmed.

• This is a large regional unit characterised by a major vegetation type and associated fauna found in a specific climate zone.
• The biome includes all associated developing and modified communities occurring within the same climatic region, e.g., forest biomes, grassland and savanna biomes, desert biome, etc.
• On a global scale, all the earth’s terrestrial biomes and aquatic systems constitute the biosphere.

In an open ocean, the large numbers of phytoplankton quickly complete their life cycles and sets of new population or crops of phytoplankton are formed every few hours or days. Thus, the cumulative energy contents that these generation after generation of phytoplankton trap in course of a year is certainly much more than trapped by only a few generations of herbivorous fishes in the corresponding time and space. The energy content trapped by the carnivores living on the herbivorous fishes is the leat.

• Ecology is the study of interaction between living organism and their environment. The basic unit of study in ecology is organism.
• An organism is a single living entity that can carry out all the functions of life, such as obtaining energy and nutrients, responding to the environment, and reproducing.

Populations grow through births and immigration and decline through deaths and emigration.

When resources become progressively limiting for a population, the growth pattern turns logistic. This means that initially, the population may experience exponential growth when resources are abundant and unlimited.

However, as resources start to become scarce and limiting, the growth rate of the population slows down and eventually levels off. This pattern is known as logistic growth.

• Exponential growth (option b) refers to a rapid and unrestricted increase in population size without resource limitations.
• Constant growth (option c) implies a steady and consistent growth rate over time, regardless of resource availability.
• Declining growth (option d) suggests a decrease in population size over time, often due to factors like limited resources or environmental disturbances.

• The epithelial cells of Bowman’s capsule called podocytes, which are arranged in an intricate manner so as to leave some minute spaces called filtration slits or slit pores.
• Blood is filtered so finely through these membranes, that almost all the constituents of the plasma except the proteins pass onto the lumen of the Bowman’s capsule.

Therefore, it is considered as a process of ultra filtration.

• Analysis of urine helps in the clinical diagnosis of many metabolic disorders.
• The presence of glucose or Glycosuria and ketone bodies or Ketonuria in urine is indicative of diabetes mellitus.

The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley. Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment.

The place where a particular organism lives called a habitat.

• It is a place where an organism can find shelter, food, mates for reproduction and, protection from predators.
• It depends on both biological and physical factors present within it.

In detritus food chain, speed of decomposition will be fast if detritus is rich in simple sugar that can be easily decomposed into glucose by saprophytes that includes bacteria and fungi.

The density of a population in a given habitat during a given period changes due to changes in four basic processes, two of which (natality and immigration) contribute to an increase in population density and two (mortality and emigration) to a decrease. In a zero population growth density natality is balanced by mortality. 
 

• Chimpanzee is closely related to man. DNA content and DNA matching are the same in both.
• This similarity is more than 99% with chimpanzee whereas 94% with a gibbon.

• Single-step that causes large mutation is called saltation.
• It is called as such because the mutation occurs suddenly and abruptly that leads to evolution in large scale.
• Hugo de Vries used this term against Darwin’s theory of evolution.

• Natural selection mainly leads to three selections.
• They are: Stabilizing selection, directional selection, and disruptive selection.
• Technical selection does not belong to natural selection.
• This classification is based on different organism-environmental relationship.

Adaptive radiation is the process of evolution in which different species in a given geographical area starting from a point and radiating to other geographical area.

An age pyramid with a wide base and narrow top indicates a population that is growing rapidly.

In an age pyramid, the width of each age group represents the proportion or percentage of individuals in that specific age group. A wide base indicates a larger population of young individuals, while a narrow top indicates a smaller population of older individuals.

When the base of an age pyramid is wide and the subsequent age groups gradually decrease in width towards the top, it suggests that there is a higher proportion of young individuals compared to older individuals. This is indicative of a population that is growing rapidly because there is a high birth rate.

Nepenthes (pitcher plant) and Drocera are insectivores plants to compensate for their protein requirement. They have green leaves that perform the photosynthesis process. So, they act as both producers as well as consumers.

• The heart is not involved in excretion. The heart is a muscular organ that pumps blood throughout the body, delivering oxygen and nutrients to the tissues and organs.
• Lungs help in excretion of carbon dioxide
• Liver helps in excretion of toxic substance
• Skin helps in removal of extra salts along with sweat.

Hence, option C is correct.

According to abiogenesis theory of origin of life, life originated from non-living matter like gases, inorganic substance and water at particular temperature and pressure.

Carrying capacity of a habitat is the maximum number of individual that can survive in given habit. There is a limitation of food, water and space in a habitat so only limited numbers of individual survive.

Ecology is the study of the relationships between living organisms and the abiotic (physico-chemical factors) and biotic components (other species) of their environment. Ecology encompasses the interactions and relationships between organisms and both their non-living (abiotic) and living (biotic) environment. It examines how organisms interact with factors such as climate, water, soil, and other organisms.

Therefore, option a) Abiotic and biotic components accurately describes the scope of ecology.

GA is a terpene derivative. Ethylene is a volatile gaseous hormone. ABA is a derivative of carotenoids. Auxin is an indole compound.