The fact that imprinting is most certain to occur if the opportunity for imprinting is presented to the organism at a very specific age indicates the existence of

a critical period

Explanation:

In developmental psychology and developmental biology, a critical period is a maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli(Wikipedia). It is a time during early postnatal life when the development and maturation of functional properties of the brain, its 'plasticity', is strongly dependent on experience or environmental influences(Sengpiel, 2007).

The fact that imprinting is most certain to occur if the opportunity for imprinting is presented to the organism at a very specific age indicates the existence of a critical period in the life of organisms.

In school, Brendan has been conditioned to get up from his seat every time he hears the school bell ring.

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for six years an artificial fertilizer is used on a apple orchard the orchard is next to a stream which empties in to a slat water bay during the last 5 years researchers have observed an increase in algae in the bay they have also sampled fish populations in the bay each year apex...

A spring is a natural discharge point of subterranean water at the surface of the ground or directly into the bed of a stream, lake, or sea. Water that emerges at the surface without a perceptible current is called a seep. Wells are holes excavated to bring water and other underground fluids to the surface.

The image shows a cross-section of land scape.

Answer : 900 kg pumpkins

Need this store of protein: 

The seed consists of three components: embryo, endosperm (sometimes perisperm), and seed-coat. Both endosperm and embryo are the products of double fertilization, whereas the seed-coat develops from the maternal, ovular tissues. The seed habit is a significant advancement in the evolution of higher plants.

Anatomy of seed :-

Seed storage proteins provide a source of amino acids and reduced N necessary for germination and early growth of the seedling.

The maltose molecule can be broken down into two individual glucose molecules with the help of an enzyme produced within a cell.

D).increasing the pH with in the cell.

Explaination:

D. The population density of beetles will decrease.

Answer with explaination:

 An attempt to document and identify all biological species living in some defined area, usually a park, reserve, or research area. The numbers of species on earth is rapidly diminishing, knowing what species are around will give us an idea of what we're losing, how our actions are affecting the environment.

Carbon dioxide with the help of diffusion reach the other cells in the leaf and the oxygen which is produced during the process of Photosynthesis is diffused out of the leaf. Hence, diffusion is the simple process by which gaseous exchange takes place.