Answer:
The F1 progeny is completely heterozygous for the <em>loci</em> of interest since they were obtained by mating between two pure-breeding plant lines. In the next generation, the backcross progeny will have homo-zygous individuals and therefore they will be more variable, resulting from meiosis in F1 hybrids
Explanation:
An F1 resulting from the cross between two pure-breeding plant lines will produce all hybrid individuals, all of them genetically (and phenotypically) identical. Meiosis in F1 hybrids is well known to produce homo-zygous genotypes and thus increases genetic diversity in progeny. For instance, for a single <em>locus</em>, the expected ratio of genotypes obtained from crossing two heterozygous parents is 1:2:1, i.e., one homo-zigous dominant individual, two heterozygous individuals (genetically identical to the parents) and one homo-zygous recessive individual; while the expected phenotypic ratio is 3:1 (i.e., 3 dominant expressing: 1 recessive expressing).
Answer is Prophase
Prophase is characterized by duplication of genetic material and the condensing of the chromatin to chromosomes. This is especially useful in cytogenetics, a genetic study of chromosomes in a cell.
The chemical called mitotic inhibitors, inhibit the formation of microtubules that pull the chromosomes apart, an essential function of mitosis.
Answer:
calmodulin
Explanation:
The calcium-modulated protein (calmodulin) is a calcium-binding receptor protein that modulates contractile proteins (i.e., actin and myosin proteins) of the skeletal muscle and non-muscle cells (e.g., platelets). Calmodulin binds to calcium ions (Ca2+) and subsequently activates a number of Ca2+ dependent enzymes (e.g., kinases or phosphatases), which finally activate/deactivate proteins in the calcium signal transduction pathway. Ca2+-ATPase pumps in the membranes of eukaryotic cells release Ca2+ from the cytoplasm and they are autoinhibited by low Ca2+ levels, while calmodulin-binding releases this autoinhibition and thus activates the pumps. In non-muscle cells such as platelets, calmodulin also mediates Ca2+ control of actin-myosin interaction by phosphorylation of the myosin light chain (MLC).
