Biology Test - 23

Both the statements are correct but the given reason is not the correct explanation. Polymerase chain reaction is used in DNA amplification.

Ampicillin resistance gene is a selectable marker that helps to check transformation by selection of transformants.

Rice is a staple food in many countries, particularly in Asia, but does not contain vitamin A or its immediate precursors. By inserting two genes from Daffodil and one gene from a bacterial species into rice plants, Swiss researchers have produced rice capable of synthesising β-carotene, the precursor of vitamin A. Vitamin A is required by all individuals as it is present in retina of eyes. Deficiency of vitamin A causes night blindness and skin disorders. This rice is called 'Golden rice' because of yellow colour of rice grains due to the presence of β-carotene.

A represents polypeptide chain C which is removed prior to insulin formation

Thorns on Acacia trees are a direct defense mechanism in plants to deter herbivores from feeding on their leaves or branches.

High reproductive rate of a parasitic plant is not a defense mechanism; it's an adaptation for survival and spread, unrelated to protecting against herbivory.

Camouflage in insects like the Monarch butterfly is an adaptation for insects, not plants, so it does not qualify as a plant defense.

CominensaHsm is the relationship between two living individuals of different species in which one is benefitted while other is neither harmed nor benefined, e.g., Small fish (sucker fish) gets stuck near the bottom of a shark with the help of it's hold fast (modified dorsal fin) and is dispersed to distant areas. It also gets protection and derives its nutrition also and shark does not get any benefit or harm. Predation is an association between members of two species in which members of one species capture, kill and eat up members of other species, e.g.. Insectivorous plants like Drosera. Antibiosis : in this one organism inhibit growth of other organism through the secretion of antibiotics. This is based on biological antagonism and also known as allelopathy, e.g.. Smoother crops e.g.. Barley rye, millets are those which do not allow weeds to grow near by. Parasitism: in this type of association one member is benefitted. (parasite) and other is harmed (host), e.g.. Parasitic bacteria, viruses.

Let's evaluate each statement:

A. Detrivores perform fragmentation.

This statement is true. Detrivores, such as earthworms and beetles, break down detritus (dead organic material) into smaller pieces in a process called fragmentation.

B. The humus is further degraded by some microbes during mineralization.

This statement is true. Microbes, including bacteria and fungi, break down humus into inorganic nutrients in a process called mineralization.

C. Water-soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching.

This statement is true. Leaching refers to the process where nutrients are washed away from the soil into lower layers or into bodies of water.

D. The detritus food chain begins with living organisms.

This statement is false. The detritus food chain begins with dead organic material or detritus, not living organisms.

E. Earthworms break down detritus into smaller particles by a process called catabolism.

This statement is false. The process by which earthworms break down detritus into smaller particles is called fragmentation, not catabolism. Catabolism refers to the breakdown of complex molecules in living organisms to form simpler ones, along with the release of energy.

Therefore, the correct answer is : Option A: A, B, C only.

In the equation GPP - R = NPP,

GPP stands for Gross Primary Productivity, NPP stands for Net Primary Productivity, and R represents the energy used by plants for their own metabolic processes, which is also known as Respiratory loss.

The sperm contacts the egg cell at zona pellucida. The zona pellucida then undergoes chemical changes which renders egg insusceptible to further encounters with another sperm. This is essential to ensure that only a single sperm fertilizes the egg.

Development is the process that leads to the formation of an organism from the zygote. Potency is the ability of a cell to differentiate into another cell type. Stemness is the potential of a cell to divide indefinitely and also differentiate to multiple different cell types.