Answer:
The correct answer is d Bill"s plasma contain B antibodies
Explanation:
As Bill"s plasma contain B antibodies that"s why his blood cells do not aggutinate when mixed with anti B serum.
Answer:
a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
Explanation:
Kinetochores have vvery important role in the cell division-mitosis.
During the metaphase of mitosis, spindle fibers attach to kinetochores. Some of the microtubules bind to kinetochore (kinetochore microtubules) while other don’t: they connect with the microtubules from the opposite pole, stabilizing the spindle.
During the anaphase, kinetochore microtubules pull chromosomes toward poles, helping the sister chromatids separate from each other.
Answer:
1-Mouth:the mechanical digestion takes place in mouth with the help of teeth. chewing is the machanical digestion of food in mouth.
2-Stomach: by the churning process. churning is the mixing of food in stomach by the movements of smooth muscles in stomach wall.
Explanation:
Answer:
Ptolemy included epicycles in his orbits.
Explanation:
Ptolomy's model of the solar system was geocentric, where the sun, moon, planets, and stars all orbit the earth in perfectly circular orbits. The problem with perfectly circular orbit around the Earth is that they do not explain the occasional backward motion, or retrograde motion, of the planets.
The Greeks insisted that the motion of the planets be perfectly circular. Ptolemy modeled the planets making small circles around a point that orbited the Earth. These smaller circles were called epicycles, and they allowed the planets to move backward relative to the background stars.
