Prolactin, also called as luteotropic hormone (LTH) or luteotropin, is a protein hormone produced by the pituitary gland of mammals, that acts with other hormones to initiate secretion of milk by the mammary glands. 

Prolactin is the hormone that stimulates milk production. During pregnancy, prolactin stimulates growth of the breast, but high estrogen and progesterone secretion prevent milk production. After delivery, estrogen and progesterone levels drop, and prolactin stimulates the secretion of milk by alveolar cells in the breast.

Lemmings reduce their number by committing suicide every 4 years. It has been regarded as a collective suicide, conscious or involuntary, caused by overpopulation. In reality, being solitary rodents by nature, when the population booms, the stronger lemmings drive the weaker and younger ones off long before the food is depleted.

For the purpose of avoiding being noticed and to save itself successfully from the snake, the prey becomes motionless. It ambushes itself well with the surroundings. The ambush may be set by hiding in a burrow, by camouflage, by aggressive mimicry, or by the use of a trap.

• Instinct behaviors are innate abilities. They occur and are present from birth onward and are not learned behaviors. It is performed by all members of their species. They are typically a fixed action pattern (FAP) that occurs as a result of a specific stimulus. For example, spinning a web by a spider, nest building and other maternal activities, migration patterns of animals, social behavior in pack animals, swimming by fish, etc.
• Hence, fish do not need to learn how to swim is an example of instinct behavior.

The action does not involve the brain and is an example of a simple reflex. When the leg of the frog is pinched, the stimulus is received by receptors on the skin that set up a sensory impulse. This impulse is carried to the spinal cord through the dorsal sensory root of a spinal nerve. The spinal cord then transforms the sensory impulse into a motor impulse. This impulse is then transmitted to the leg muscles. The muscles on receiving the impulse contract and the leg is withdrawn to avoid the stimulus. So, the correct option is 'simple reflex'.

Prolactin (PRL) is a hormone that stimulates milk production. Prolactin also plays an essential role in metabolism, regulation of the immune system, and pancreatic development.

Prolactin (also called as luteotrophic) hormone is associated with lactation (secretion of milk from the mammary gland). It is a hormone released by the pituitary gland that stimulates breast development and milk production in women. Therefore, to yield more milk cow is injected with prolactin hormone. 

Colostrum is a milky fluid that comes from the breasts of humans, cows, and other mammals the first few days after giving birth, before true milk appears. It contains proteins, carbohydrates, fats, vitamins, minerals and proteins (antibodies) that fight disease-causing agents such as bacteria and viruses. Antibody levels in colostrums can be 100 times higher than levels in regular cow’s milk.

Chameleons camouflage themselves in a variety of different ways but most famously by changing the colour and pattern of their skin. Most chameleons can change colour and they do this by expanding or contracting cells in their skin that contain different pigments. They can blend into their surroundings by altering the colour of their skin to match the background. Chamaeleon (girgit) shows protective colouration with its surrounding e.g., twig. 

Imprinting is defined as a learning process in which an offspring establishes species specific behaviour patterns along with recognition and attraction towards individuals of own species and even certain specific individuals (like parents). This process is classified as phase sensitive learning independent of external behaviour or other characteristics. In case of salmons, it has been theorized by Wisby and Hasler that they imprint on the unique odour of the natal water and as adults follow the same odour cues to their birth homes for spawning. Hence the correct answer is 'Imprinting'.   

Colostrum (also called as first milk) is the thin yellowish fluid secreted by the mammary glands at the time of parturition and which precedes the production of true milk. It provides a nursing infant with essential nutrients and infection-fighting antibodies (called as immunoglobulin) to protect the newborn against disease. IgA is the major immunoglobulin in colostrum. It protects from inhaled and ingested pathogens.

1. During mating, a male generally shows agressive behaviour as a form of superiority over other fellow males.
   2. Pheromones are used as a form of communication between two mating species.
   3. A male generally marks it's territory inorder to avoid anymore competition for mating.
   4. Visual communication is primarly used to locate and identify the mating partner.
   So, the correct option is 'Search image'.

So the correct answer is 'instinctual'.

Fish are given food at the same time as a tap on their glass bowl and soon learn to approach when a tap sounds even in the absence of food - it is an example of Classical conditioning.

A form of learning that occurs during a brief genetically determined critical period shortly after birth is called as imprinting. Habituation occurs throughout the life where individual learn to ignore the irrelevant stimuli. Reflex is a response to external or internal stimuli experienced throughout the life. Instinct and dominance are innate behaviours. The correct answer is D.

Because archegonia of pteris secrete a chemical malic acid which attracts only sperms of Pter!s thermostatically.

A form of learning that occurs during a brief genetically determined critical period shortly after birth is called as imprinting. Salmon learned, shortly after birth, about their birth place as they found themselves there just after birth. This makes them recognize the place and go there for breeding. Conditioned is also a learned response in which stimulus becomes associated with a consequence. Habituation is the most complicated form of learned behavior and includes applying something already learned to a new situation without a period of trial and error. The reasoning is making the concept of cause and effect in particular context. Thus, the correct answer is option E.

Circadian rhythm or diurnal rhythm is any 24 hour  periodicity in the behaviour or physiology of animals or  plants .Examples are sleep /activity cycle in many  animals and the growth movements of plants. Circadian  rhythms are generally controlled by biological clocks.

All flightless  birds belong to the super -order Ratitae e.g. Emu, Panguin, Rhea, win, Moa, Cassowary .

Sea cows (Rhytina) belong to order Sirenia of mammals. Presence of blubber and few hairs are characters of order sirenia. 

Bed bug ,sand fly silk worn are placed in tracheate  group of Arthropoda because they have trachae for  respiration Embryonic development of echinoderms shows a number of similarities with those of chordates .

The yellow-coloured milk secreted by cattle soon after the birth of a calf is called as colustrum. Colostrum contains antibodies to protect the newborn against disease. Colostrum is known to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG and IgM. However, the most abundant immunoglobulin in colostrum is IgA.

The yellow-coloured milk secreted by cattle soon after the birth of a calf is called as colostrum. It is rich in antibodies that confer passive immunity to the newborn

An organism is said to behave altruistically when its behaviour benefits other organisms, at a cost to itself. The costs and benefits are measured in terms of reproductive fitness, or expected number of offspring. So by behaving altruistically, an organism reduces the number of offspring it is likely to produce itself, but boosts the number that other organisms are likely to produce. 

A liger is a result of breeding a male lion to a tigress. A tigon is a result of breeding a male tiger to a lioness. Since lions and tigers do not exist in the same areas, this is not something that happens in the wild.

Tendrils is a modification in cucumber that helps the plant to climb higher and higher. These are skinny, wire-like structures along the plants stem. It also helps in grasping in cucumber. These tendrils are the modification of axillary buds located at the axial part of the leaf.

The orchid family (Orchidaceae) is subdivided into 5 subfamilies, 22 tribes and 70 subtribes and 850 genera are informal as alliances.

Most bats use frequencies in the range 20-80 kHz, only a few bats use frequencies less than 20 kHz.

Here the food chain be :
Grass Grasshopper Frog Snake Eagle The organism which occurs at the highest trophic level in the food chain will have the maximum concentration of harrnful chemicals in its body. since, eagle occurs atthe highest trophic level, therefore, it will have the maximum concentration of harrnful chemicals in its body.

Instinct is a kind of behaviour which does not involve any prior learning and is inherent and automatic. Thus, the loss of sensitivity to unimportant stimuli is a natural act which is instinctive in nature. For example, dancing of honeybees in the direction of food, animal fighting and courtship behaviour are are instinct behaviour. 

A form of learning that occurs during a brief genetically determined critical period shortly after birth is called as imprinting. Instinct is an inborn behaviour characteristic to a species and is often a response to specific environmental stimuli. Conditioning is also a learned response in which stimulus becomes associated with a consequence. Habituation is the most complicated form of learned behavior and includes applying something already learned to a new situation without a period of trial and error. Reasoning is making concept about cause and effect in particular context. Because the chicks learnt to follow mother goose and mother hen just after birth; it is imprinting. 

Imprinting is a form of learning that occurs during a brief genetically determined critical period shortly after birth. Habituation is the most complicated form of learned behavior and includes applying something already learned to a new situation without a period of trial and error. The reasoning is making the concept of cause and effect in particular context. Reflex and dominance occur during a late phase of life. 

Both habituation and imprinting are simple learned behaviours. Both are non associative learning process which means not associated with any reward or punishment. In habituation, the animal becomes habituated to the specific type of stimulus after repeated exposure. In imprinting, the learned behaviour occurs at a particular stage of maturation process in life. It mostly occurs in early stage of life of animals. Like the animal first recognizes the mother. This behaviour helps the animal in their survival in young age. 

Behaviour of organisms which belong to the same species can be seen in periodical cicadas that emerge the same year. The nymphs of periodical cicadas develop underground for 13 to 17years and live on juices from plant roots. After this period, they emerge from the soil and molt into winged adults. There are seven species of periodical cicadas four with 13-year life cycles and three with 17-year cycles. Each species of the periodical cicada has a distinctive song.

A form of learning that occurs during a brief genetically determined critical period shortly after birth is called as imprinting. Because the chicks learnt to follow mother goose and mother hen just after birth; it is imprinting. If they were exposed to mother pig shortly after hatching, they would exhibit pig like behavoiur.

Batesian mimicry refers to the resemblance of a harmless or palatable species with that of a dangerous or unpalatable one to make predators avoid them. A more common and distinct poisonous species present in the same area as mimic become familiar to predators of mimic and thereby increase the effectiveness of mimicry. Competition between mimic and poisonous species would harm either of them while mimicry is an adaptation for the protection of mimic. Thus, the correct answer is option C.

Bats are nocturnal flying mammals which do not employ eyesight for location of their path. food place of rest etc. They produce high frequency sound which produces echoes after striking various objects on the principle of sonar. Echoes are then analysed by bats to know their path.  

Copying the behaviour of someone observed is called imitation. It is seen in animals including humans as the most common learning process. Imitation is the social behaviour or conduct that a person unconsciously or passively learns and adopts. For example, drinking alcohol to fit into the group. It is observed that college students are influenced by peer pressure. They develop their concepts on the basis of the thought of peer groups. They want to be socially adapted by the group and they develop the habit of drinking. So, we can say that drinking alcohol is the temporary imitation of peer's behaviour.

Dogs were used as an experimental model for the investigation of conditioning behavior and the experiment was done by Russian physiologist Ivan Pavlov and was recognized in the world by Pavlov's dog experiment based on classical conditioning theory in which he showed that they could be conditioned to unconsciously associated with neutral, unrelated event with feeding.

Imitation is a behavior where an organism learns from another and replicates or copies by observing. Many animals have this imitating behavior like parrot, pigeon, Japanese quailmonkey and beluga whales which imitate humans.

Instinct is a kind of behaviour which does not involve any prior learning and is inherent and automatic. When there is stimulus received, the release of adrenaline occurs which is known as the adrenaline rush. This results in the development of response which is automatic and instant. 

1. Conditioning is a behavior in which a response becomes more frequent or predictive to a particular action or environment as a result of reinforcement.
2. Imprinting is considered to be the kind of phase-sensitive learning that is very fast and does not depend on the consequences of behavior.
3. Instinct is a type of behavior that is genetically present and is considered to be the response of a particular stimulus like fear from a snake.
4. It is a behavior in which the human try and copy others things.

Conditioning is the type of behavioral change which is shown towards the discriminative stimulus. The stimulus is added with some kind of attraction or extra benefits. The stimulus is often associated with a consequence. The strength of the behavior depends on the stimulus and the consequence. The type of behavior will always rely on the stimulus and its strength. When there is the certain attractive image used to describe an advertisement, this is done to attract the people to buy the product. 

A change which evokes a response is known as the stimulus. It greatly affects the human behaviour. The change in the external and internal environment act as a sudden stimulus and creates a response. The sequential change in the conditions greatly influence the human behavioural pattern.

Copying the behaviour of someone observed is called imitation. It is seen in animals including humans as the most common learning process. Imitation is the social behaviour or conduct that a person unconsciously or passively learns and adopts. For example, yawning in humans and the child attempt in the first year to imitate sounds to get the attention of his mother or others. So, the correct option is C.

1. A person's fear of anything comes under the behavior of instinct.
   
2. Conditioning is the particular or predictive response towards particular stimuli.
3. Imprinting is a type of behavior that is genetically present and is considered to be the response to a particular stimuli.
4. Imitation is a behavior in which an organism tries to copy others.

Positive reinforcement for a conditioned behaviour can be provided by adding an appetitive stimulus at the end of correct behaviour. It can be in the form of a praise.

• Conditioning is a behavioral process whereby a response becomes more frequent or more predictable in a given environment as a result of reinforcement, with reinforcement typically being a stimulus or reward for the desired response.
  
• Imitation is an advanced behavior whereby an individual observes and replicates another's behavior. 
  
• Both Imitation and conditioning are part of the learning process in organisms. Hence, option D is correct.

Dogs were used as an experimental model for the investigation of conditioning behavior and the experiments were done by Russian physiologist Ivan Pavlov in which he showed that the dogs could be conditioned unconsciously with neutral, unrelated event with feeding.

A) An involuntary response is not under conscious control. It generally constitutes the reflexes.

A) Imitation is a behavior in which an organism observes, learns and reciprocates other organisms.

Singing is an essential part of bird life, but it's costly in terms of time and energy. Singing loud and proud first thing in the morning tells everyone within hearing distance that a bird is strong and healthy enough to survive the night. This is attractive to potential mates, and lets the competitors know that they still around and in charge of your territory. 

Courtship display are certain behaviors that are displayed by an animal in an attempt to attract a mate. A small area occupied by single males for displaying courtship traits is called as Lek. Lek is an animal behaviour. Lek. In this, males of a particular species perform courtship displays. It is also called as arena behaviour. It is seen in birds, mammals. A niche of an organism is a functional role it plays into an ecosystem. Territory is a sociographical area that is defended by group of animals of a particular species from other animals of different species for purposes like mating, nesting, roosting, feeding. 

Since crocodiles plummet from a typical precursor with dinosaurs, they can give a helpful developmental correlation with feathered creatures. (In spite of their appearance, flying creatures are more firmly identified with crocs than reptiles are.). Fossilized skulls of child dinosaurs demonstrate a similar example they take after grown-up winged animals.

Classical conditioning refers to a learning procedure in which a biologically potent stimulus (e.g. food) is paired with a previously neutral stimulus (e.g. a bell).

The type of animal behavior depends on the stimulus provided and the response generated by the stimulus. When the stimulus is generated, the stimulus is analyzed by the brain or the spinal cord. There are various biochemical reactions which take place in response to the stimulus which is received. The type of response by the animal as a part of the behavior is based on these biochemical reactions. 

Instinct behaviour is the autonomic response to the stimuli (external) or environmental conditions. It develops when a human rationalises several voluntary and involuntary actions according to his/her will. It is the behaviour intrinsic to the person. So, the correct option is 'Autonomic response'. 

Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules (the "scraper" or plectrum) being moved across a finely-ridged surface (the "file" or stridulitrum—sometimes called the pars stridens) or vice versa, and vibrating as it does so, like the dragging of a phonograph needle across a vinyl record. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups. Common onomatopoeic words for the sounds produced by stridulation include chirp and chirrup.