In most cases, the two major climatic factors affecting the distribution of organisms in terrestrial ecosystems are the amount of water and temperatures. Terrestrial ecosystems rely on the sun's energy to support the growth and metabolism of the organisms. Plants use the sunlight, then they supply the organisms that are higher up the food chain with energy and the structural buildings blocks of life. Water is also essential for the survival of these organisms.
The conditions that must be met before a specific pathogen is proved to cause a disease include; Pathogen must be present in every case in which the disease is found, pathogen must be isolated and grown outside the body in a pure culture, healthy animals infected with culture must develop the disease and finally the pathogen must be re-isolated and cultured from the newly sick animals and must be identical to the original pathogen.
Answer:
The first stage is the egg stage. Eggs are usually laid in or near water. A frog can lay thousands of eggs at once. The eggs are laid in large groups. There are covered in jelly which makes them slippery. The jelly protects them from other animals eating the eggs.
The second stage is the tadpole stage. A tadpole hatches from the egg. The tadpole breathes using gills and moves like a fish. It uses its long tail to swim. Tadpoles eat tiny water plants.
The third stage is the froglet stage. It grows lungs and legs. Its gills disappear. Its tail gets shorter until it disappears too. The froglet swims to the top of the water to breath.
The last stage is the adult stage. A frog can leave the water now and live on land. It eats insects, worms and snails. Mother frogs return to the water to lay eggs. the air.
Answer:
This binding causes a conformational change in the receptor which enters into the nucleus and binds DNA to activate transcription
Explanation:
Testosterone is a steroid hormone responsible for inducing protein synthesis and growth of tissues with androgen receptors. Testosterone receptors, also known as androgen receptors, are a class of nuclear receptors activated by binding androgenic hormones (e.g. testosterone) in the cytoplasm, whose binding induces a conformational change of the receptors that are subsequently translocated to the nucleus. Within the cell nucleus, these activated receptors form homodimers that bind DNA in order to promote the transcription of target genes capable of regulating cell growth, cell cycle progression and survival.
