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.
Answer: The DNA double helix is held together by two types of bonds,
covalent and hydrogen.
Explanation: Covalent bonds occur within each linear strand and strongly
bonds the bases, sugar and phosphate groups.
uracil
Explanation:
because the rest are part of the DNA strand
It was probably because when a area had too much pollution, they could easily migrate away somewhere else by flying, while humans have to stay everywhere. Another reason could've been that birds can adapt to places quicker than other animals.
Hope it helps!
Answer:
The correct option is D. Crossing over and independent assortment are the causes of genetic variation.
Explanation:
In the process of meiosis, crossing over is a phenomenon through which exchange of genetic segments takes place among the homologous chromosomes.
The process of independent assortment describes how different genes assort differently during meiosis.
Both the process of crossing over and independent assortment are the basis of the genetic variations seen in the world.
