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Competition is the ecological interaction in which the individuals explore the same ecological niche or their ecological niches partially coincide and therefore competition for the same environmental resources takes place.

Competition is harmful for all participating beings and thus it is classified as an inharmonious (negative) ecological interaction.

Mutualism is the ecological interaction in which both participants benefit and that is obligatory for their survival. Mutualism is a harmonious (positive) ecological interaction. Mutualism is also known as symbiosis. Examples of mutualism are: the association between microorganisms that digest cellulose and the ruminants or insects within which they live; the lichens, formed by algae or cyanobacteria that make organic material for the fungi and absorb water with their help; nitrifying bacteria of the genus Rhizobium that associated to leguminous plants offer nitrogen to these plants.

Colonies are functional integrated aggregates formed by individuals of the same species. Colonies are often confused with a single individual. Examples are the coral reefs, by-thewind sailors and filamentous algae.

Societies are interactions for labor division and collaboration among individuals of the same species. Human societies are examples of ecological societies; other species, like bees, ants, termites, wolves and dolphins, also form societies.

Protocooperation is the ecological interaction in which both participants benefit but which is not obligatory for their survival. Protocooperation is a harmonious (positive) interspecific ecological interaction. Examples of protocooperation are: the action of the spur-winged plover that using its beak eats residuals from crocodile teeth; the removal of ectoparasites from the back of bovines by some birds that eat the parasites; the hermit crab that live inside shells over which sea anemones live (these offer protection to the crab and gain mobility to obtain food).

Harmonious, or positive, ecological interaction is that in which none of the participating beings is harmed.

The main harmonious intraspecific ecological interactions are colonies and societies. The main inharmonious intraspecific ecological interactions are intraspecific competition and cannibalism.

In cannibalism an individual eats other of the same species (occurs in some insects and arachnids). Since it is an interaction between beings of the same species and at least one of them is harmed (the other is benefited) the classification as inharmonious intraspecific ecological interaction is justified.

Intraspecific competition occurs in practically all species, for example, the competition of humans for a job.

Examples of interspecific competition are: the dispute among vultures, worms, flies and microorganisms for carrion and the competition between snakes and eagles for rodents.

Commensalism may involve obtainment of food (for example, the innocuous bacteria of the human gut), shelter or support (epiphytes on trees) and transportation (pollen carried by insects or birds). The commensalism that involves obtainment of shelter is also called inquilinism.

Commensalism is the ecological interaction in which one individual benefits while the other is neither benefited nor harmed. Commensalism is a harmonious (positive) ecological interaction, since none of the participants is harmed. An example of commensalism is the numerous bacteria that live in the skin and in the digestive tube of humans without being pathogenic or beneficial. They are innocuous bacteria living in commensalism with humans. 

The plasmodium infects the human blood causing destruction of red blood cells and it also affects the liver. Malaria characterizes by periodical episodes of fever, chills and sweating that can be accompanied by headache, nausea, vomiting and jaundice. The destruction of red blood cells may lead to anemia and hypoxemia.

The infection by Plasmodium falciparum if not treated can cause other complications and even death.

The vector of malaria is a mosquito of the genus Anopheles, also called anopheline. In opposition to the mosquito vector of the dengue fever, the anopheline has nocturnal habits.

In the life cycle of the plasmodium humans are the intermediate hosts (where asexual reproduction takes place) and the vector mosquito is the definitive host (where sexual reproduction occurs). 

Biotic components of an ecosystem include  Producers, consumers and decomposers

The main preventive measures against malaria are the elimination of the vector mosquito, treatment of infected people, avoidance of the mosquito bite, information for travelers to endemic areas and the use of preventive medicines.

Intraspecific ecological interactions are those between individuals of the same species. Interspecific ecological interactions are ecological interactions between individuals of different species.

The typical chills and fever episodes of malaria correspond to the phase when red blood cells are destroyed after the erythrocytic schizogony of the plasmodium life cycle.

Lactobacillus  bacteria is convert milk into curd.

 61  of them coded for amino acid.

Sulphur or calcium

1. Older regions because minerals are remobilised from older regions into younger regions.

2. Ca, Deficiency symptoms are noticed in younger tissues because it forms the structural part.

Most plants cannot use it because atmospheric nitrogen is inert in its nature. Nitrogen fixers in soil can convert nitrogen gas into nitrates or nitrite or ammonium forms. These compounds enter the plants as nutrients through the roots and are assimilated as organic nitrogen.

Edible part of litchi is Aril.

• If the elements are actively mobilized, the older part of plant show deficiency symptoms.
• If they are not mobilized, the deficiency symptoms are first observed in younger regions.

Insectivorous plants fulfill their nitrogen requirements from insects and small animals trapped by their leaves(a pitcher).

Thigmotropism is the movement or growth of the plant in response to mechanical stimuli (touch or physical contact), as when a plant grows around a supporting rod. It occurs for example in grape and passionfruit vines, etc.

Photoperiodism is the biological response presented by some living beings to their daily time of light exposure (photoperiod). 

In 1860, Julius von Sachs, a prominent German botanist, demonstrated, for the first time, that plants could be grown to maturity in a defined nutrient solution in complete absence of soil. The essence of all these methods involves the culture of plants in a soil-free, defined mineral solution. These methods require purified water and mineral nutrient salts.

Purification of water and nurtients salt is important to rule out other influencing factors. The presence of pure nutrients will give clear cut scientific results. This will help in making a sound basis for the right prediction.

The Criteria for essentiality are

1. The element must be necessary for supporting normal growth and reproduction 

2. In the absence of elements, the plants do not complete their life cycle or set the seeds. 

3. The element must be directly involved in the metabolism of the plant. 

4. The requirement of the element must be specific and not replaceable by another.

Photoperiod is the daily time period of light exposure of a living being. The photoperiod may vary according to the period of the year.

The criteria for essentially of an element are given below: 

1. The element must be absolutely necessary for supporting normal growth and reproduction. In the absence of the element, the plants do not complete their life cycle or set the seeds.

2. The requirement of the element must be specific and not replaceable by another element. In other words, deficiency of any one element cannot be met by supplying some other element. 

3. The element must be directly involved in the metabolism of the plant. All elements that are present in a plant do not fulfill these criteria hence cannot be essential for plant survival.

The critical photoperiod is the limit of the photoperiod duration for the occurrence of some biological response. This limit can be a maximum or a minimum, according to the characteristics of the biological response and to the studied plant.

To determine the critical photoperiod relating to flowering, 24 groups of plants of the same species can be taken and the following experiment can be done: Each group is submitted to a different photoperiod, the first group to 1 hour of daily exposure to light, the second to 2 hours, the third to 3 hours, and so on, until the last group is exposed to 24 hours. It is observed later that beyond a specific duration of light exposure plants present or do not present flowering and the remaining submitted to a shorter photoperiod present opposite behavior. The duration of the light exposure that separates these two groups is the critical photoperiod. 

Correct option: (4) Leaves

Explanation: 

During flowering, photoperiodic stimulus is perceived by leaves of plants.

(a) Repetitive DNA and satellite DNA

(b) mRNA and tRNA

(c) Template strand and coding

 Noncoding sequence  is called Junk DNA.

(1) CGU, CGC, CGA

(a). Some of the important goals of HGP were as follows: 

(i) Identify all the approximately 20,000-25,000 genes in human DNA, 

(ii) Determine the sequences of the 3 billion chemical base pairs that make up human DNA, 

(iii) Store this information in databases, 

(iv) Improve tools for data analysis, 

(b). It helps in solving challenges in 

• health care 
• agriculture 
• energy production 
• diagnosed disorder and treat disorders 

(c) BAC - Bacterial Artificial Chromosomes 

It is used as vector for cloning of DNA fragments

C.Primer is double stranded

Correct option: (1) after entry of sperm but before fertilization

Explanation: 

Extrusion of second polar body from egg nucleus occurs after entry of sperm but before fertilization.

The entry of sperm into the ovum induces completion of the meiotic division of the secondary oocyte. 

Entry of sperm causes breakdown of metaphase promoting factor (MPF) and turns on anaphase promoting complex (APC).

Any unit of classification is called taxon

The sudden withdrawal of a body part which comes in contact with objects that are extremely hot, cold pointed or animals that are scary or poisonous.

The entire process of response to a peripheral nervous stimulation, that occurs involuntarily, i.e., without conscious effort or thought and requires the involvement of a part of the central nervous system is called a reflex action.

The reflex pathway comprises at least one afferent neuron (receptor) and one efferent (effector or excitor) neuron appropriately arranged in a series.

The afferent neuron receives signal from a sensory organ and transmits the impulse via a dorsal nerve root into the CNS (at the level of spinal cord). The efferent nueuron then carries signals from CNS to the effector. The stimulus and response thus forms a reflex arc.

The mechanism of breathing involves two main processes: inspiration and expiration. Inspiration occurs when the diaphragm and the external intercostal muscles contract. Expiration occurs when the diaphragm and the intercostal muscles relax.