Answer:
C
Explanation:
Phototaxis (phototactic response) is the cellular behavior in which cells swim toward or away from the light source. The euglena have eyespots that detect light so that it can move toward sunlight for photosynthesis.
One of the difference is that fishes have single circulation but humans have double circulation of blood.
The right answer is B) crossing over.
Crossing-over is a genetic phenomenon that occurs during meiosis and contributes to genetic mixing during reproduction (genetic recombination).
At the end of prophase 1 (early metaphase 1) of meiosis, the homologous chromosomes (i.e. of the same pair) overlap thus forming characteristic features called "chromatid tetrads" and exchange fragments of chromatids. The result is the intra-chromosomal mixing of the alleles
<u>Development happens quickly during the prenatal period, which is the time between conception and birth. This period is generally divided into three stages: the germinal stage, the embryonic stage, and the fetal stage. The two-week period after conception is called the germinal stage. </u>
