Answer:
Four daughter cells are produced each with 40 chromosomes. The daughter cells would exhibit genetic variations and would not be genetically identical to each other.
Explanation:
Meiosis is a cell division that forms four daughter cells from one parent cell as two sequential division meiosis I and meiosis II do not include any DNA replication between them. Crossing over during prophase-I of meiosis-I includes the exchange of genetic segments and occurs between the homologous chromosomes. It produces new gene combinations in the daughter cells which were otherwise not present in the parent cell.
Since there is no DNA replication between meiosis I and meiosis II, the daughter cells have half the number of the chromosomes compared to the parent cell. This occurs as homologous chromosomes move towards the opposite pole during anaphase I.
Therefore, a parent cell with 80 chromosomes will make a total of 4 daughter cells by meiosis. Each daughter cell would have 40 chromosomes. These daughter cells would have some new gene combinations and would be genetically dissimilar among themselves.
The brain and is divided into two parts called the left and right cerebral hemispheres. The two hemispheres are connected by the corpus callosum.
Answer:
A.The hole in the ozone layer
Explanation:
• Montreal protocol is an international treaty that was signed to control the use of substances that are resulting in the depletion of the ozone hole.
This treaty was signed in the year 1987 and became effective form 1989.
• Since the time that this treaty has come into force, there has been a significant improvement in the ozone hole that was observed over Antarctic as it's size has decreased.
• This improvement has been possible because the treaty helped to phase out chemicals such as chlorofluorocarbons, carbon tetrachloride, etc. that are responsible for ozone hole depletion.
Like other succulent plants, most cacti<span> employ a special mechanism called "crassulacean acid metabolism" (CAM) as </span>part<span> of </span>photosynthesis<span>. Transpiration, during which carbon dioxide enters the plant and water escapes, </span>does<span> not </span>take place<span> during the day at the same time as </span>photosynthesis<span>, but instead </span>occurs<span> at night.</span>