True
DNA are cells that carry genetic codes and are passed down through generations of offspring. New cells can only arise from existing cells!
Answer:
have curved protofilaments at their plus ends
Explanation:
Microtubules are polymers of tubulin proteins that function as the cytoskeleton of eukaryotic cells. Microtubules are dynamic structures that can grow and shrink at a rapid rate. During this process, tubulin subunits can associate and dissociate at the plus end of the protofilament. Tubulin subunits bind to two GTP molecules, one of which is hydrolyzed to GDP after assembly. When microtubules are unstable, protofilaments curl outwards because GDP-bound tubulin has a weak affinity (thereby curving it) and disassemble. The dynamic stability of microtubules is regulated by a feedback loop: when microtubules shrink, free tubulin concentration increases and microtubules start to grow. As microtubules grow, free tubulin concentration decreases and the rate of GTP-tubulin addition also decreases.
Answer:
The universe is the answer
During metaphase 1, the spindle fibers attach to the centromeres of each chromosome. Both kinetochores of each sister chromatid pair are turned toward the same pole. And 2 members of each chromosome pair (sister chromatids) are pulled into each new cell during anaphase 1.
I think the answer you want is they are called chromatids.