The correct answer is this one: "A.When actin filaments are pulled toward the center of the sarcomere, the fiber shortens." The statement that accurately describes the way in which a muscle moves is when actin filaments are pulled toward the center of the sarcomere, the <span>fiber shortens</span>
DNA polymerases add nucleotides to the 3′ end of a polynucleotide chain. ... To initiate this reaction, DNA polymerases require a primer with a free 3′-hydroxyl group already base-paired to the template. They cannot start from scratch by adding nucleotides to a free single-stranded DNA template.
How is DNA replicated? Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment. During separation, the two strands of the DNA double helix uncoil at a specific location called the origin.
The right answer is D) 9 groups of 3 microtubules
Centrioles are the constituents of a so-called centrosome structure: every animal cell has a centrosome, which is made of two centrioles and which together form a functional unit. A centriole consists of nine triplets inclined microtubules, surrounded by a number of proteins.
Heat from the Earth's core and radiation from the Sun is transferred to the surface of the Earth by conduction. Contact of the atmosphere with these warm surfaces transfers thermal energy, which then heats up the rest of the air through convection.
The atmosphere is also slightly heated by absorption of electromagnetic radiation from the Sun. The warm land and water radiates infrared, some of which is absorbed by the atmosphere, adding to its thermal energy. The remaining heat on the surface is sent out into space in the form of infrared radiation.
