By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth. There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. This is why scientists cannot be certain about how life began.
Answer:
D. the homologous chromosomes are paired AND the spindle is formed
Explanation:
Meiosis is the type of cell division that results in four daughter cells with each having a reduced number of chromosomes (by half). Both meiosis and mitosis occur in different stages including prophase, metaphase, anaphase etc but meiosis occurs in two series of division processes called meiosis I and meiosis II.
In prophase I of meiosis, homologous chromosomes, which are similar but non-identical chromosomes from male and female parents pair to form tetrad or bivalent. This pairing of homologous chromosome is unique and peculiar to MEIOSIS but never mitosis.
Answer:
A vaccine activates our immune system without making us sick. Many dangerous infectious diseases can be prevented in this simple and uncostful
drug .Vaccines have eliminated some of the most dangerous, fatal diseases in human history.
Answer:
During the course of a continuous isometric contraction of given strength, the electrical activity progressively increases. This is due to recruitment of motor units taking place to compensate the decrease in force of contraction occurring in the fatigued muscle fibres.
Explanation:
Answer:
Option C.
Ocean acidification is the main ecological problem due to mariculture.
Explanation:
- Mariculture also known as the aquaculture that stands for the fish farming occupation.
- The main ecological problem that mariclture addresses is the environmental degradation especially the water pollution.
- Many studies suggests that the tradition of mariculture has been increasing the acidificaton in ocean water that is directly affecting the marine organisms and plants.
- A build up of organic material beneath fish farms impacts the flora and fauna of an area.
- That makes drastic changes on sediment chemistry.
