Explanation:
Crossing over, or genetic recombination contributes to genetic variation and diversity.
In early Prophase I of meiosis, crossing over occurs. This is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined. The chromosome pairs form tetrads held together at chiasmata.
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained. Conversely in meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells (sperm or eggs), each containing half the number of chromosomes as its parent cell.
During the process of prophase I one the nuclear envelope containing chromosomes has only partly broken down homologous chromosomes are joined together by proteins and a complex or pairing call synapsis- corresponding genes on chromatids are aligned precisely. The syanpsis allows for crossing over which is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
Crossing over contributes to genetic variation and diversity; novel gene combinations in gametes are formed, which are not present in parent chromosomes. Genetic diversity describes all the genetic characteristics or traits within a species.
Learn more about mitosis at brainly.com/question/4303192
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B
Vaccinations protect people when they are exposed to the microorganism to which they were vaccinated. This secondary response happens when the person is exposed to the microorganism. At that time, IgG production is a lot higher, making it the main antibody class in the second response. IgM is more active when it comes to the first exposure. A lot of people who have allergies have IgE in their bodies, too. IgA is the most common secretory antibody, and it stops pathogens from attaching and invading through the mucosal membranes of the body.
Answer:
a. All of these
Explanation:
All of these options are correct
Answer:Renewable resources include biomass energy (such as ethanol), hydro-power, geothermal power, wind energy, and solar energy. Biomass refers to organic material from plants or animals. This includes wood, sewage, and ethanol (which comes from corn or other plants).
So a natural resource would be trees because wood comes from trees.
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Answer:
It includes three eons, the Hadean, Archean, and Proterozoic.
Explanation:
