Answer: crossing over happens in prophase 1.
Explanation: ( in Portuguese ) os cromossomas homólogos, na profase 1 da meiose, tocam-se, trocando informações sobre o ADN. A esse processo chama se crossing over.
Answer:
B. the combination of modern genetics and Darwinism.
Explanation:
The modern synthesis refers to the concept which combined the theory of inheritance by Mendel and theory of evolution by Charles Darwin. The theory also used the concept of Theory of germplasm.
The modern synthesis concept came in the early 20th century when the studies were going on Mendel's theory and the evolutionary aspects. The concept led to the formation of new concepts like the macroevolution, microevolution and the evolution affected by mutation of genes.
Thus, Option-B is correct.
Answer: C. The C horizon is very deep.
Horizons are the layers of soil develops as a result of soil formation. Horizon lies parallel to the earth surface. Each horizon differs from the other on the basis of amount or organic matter present, color of the soil, texture of soil and other components making up horizon, and amount and type of minerals present in the soil.
C horizon is the horizon that lies deeper region of the collective soil horizon. It consist of unweathered or partially weathered rocks or their aggregates. Therefore, it retains the original chemical composition of the parent rock. This results in the higher mineral content as compared to other horizons. This horizon also lacks the organic matter as no or very little decomposition activity of plant and animal matter takes place. Therefore, color of soil in this horizon in the absence of organic matter remains light.
Hence, a sample of soil from a C horizon is light brown in color and has a high content of a mineral called feldspar is because of the fact that the C horizon is very deep.
Answer: muscle contraction of sustained force resulting from repeated action potentials. (Option A)
Explanation: Tetanus is also called physiologic tetanus. Tetanus refers to the contraction of the muscle, which is established when the motor nerve that supply nerves to a skeletal muscle produces action potentials at a very high degree.
However, tetanic contraction is usually a normal process (such as when carrying a heavy box). Also, muscles can be shorten, lengthen or remain constant length during tetanic contractions.
Answer:
Hydrosphere and Biosphere
Explanation:
The biosphere, also known as the "ecosphere", is the worldwide sum of all ecosystems (this would represented by the fish).
The hydrosphere is the combined mass of water found on, under, and above the surface of a planet earth, minor planet or natural satellite (this would be represented by the water).
