Answer:
the layer of the earth's atmosphere that contains a high concentration of ions and free electrons and is able to reflect radio waves. It lies above the mesosphere and extends from about 50 to 600 miles above the earth's surface.
Explanation:
Hooks c. streamlined bodies
. tentacles .
Answer:
The correct answer is -
Euglena - single-cell organism
Onion bulb - organ
Blood - tissue (connective tissue)
Explanation:
The level of organization of an organ, or organism could be cellular level, tissue level, the organ level, organ system, or a complete organism. These levels are formed by assembling the lower level of the organization.
Euglena is a single-cell eukaryotic organism found in freshwater. These organisms have a very simple level of an organism which is cellular level. The onion bulb is the organ of the onion plant composed of shortened, compressed, underground stems (tissue) that are an organ-level organization.
The blood is considered as connective tissue due to the blood cells present in the matrix called plasm thus, blood is connective tissue.
Random orientation of homologous pairs of chromosomes during meiosis I results in alternative arrangements that contribute to genetic variation in offspring. This is called "independent assortment".
<u>Explanation:</u>
The sets of homologous chromosomes, also recognized as bivalents or tetrads, align along the metaphase plate in a random order in metaphase I of meiosis I. Another way for cells to incorporate genetic variation is by spontaneous orientation. Mendel's independent assortment law stipulates that, independently of one another, the alleles of two or more different genes are sorted into gamets.
In other terms, for one gene, the allele that a gamete receives does not affect the allele that is obtained for another.Genetic recombination (by random segregation) and crossing over during meiosis creates daughter cells each containing different combinations of maternally and paternally coded genes.
