<span>A mature sporophyte produces spores by meiosis, a process which reduces the number of chromosomes to half, from 2n to n. Because meiosis is a key step in the alternation of generations, it is likely that meiosis has a fundamental adaptive function. The nature of this function is still unresolved (see Meiosis), but the two main ideas are that meiosis is adaptive because it facilitates repair of DNA damages and/or that it generates genetic variation.
The haploid spores germinate and grow into a haploid gametophyte. At maturity, the gametophyte produces gametes by mitosis, which does not alter the number of chromosomes. Two gametes (originating from different organisms of the same species or from the same organism) fuse to produce a zygote, which develops into a diploid sporophyte.</span>
Answer:
C) The follicular tags are stretched.
Explanation:
Follicular tags are the parts of the follicule root that are still attached to the end of the hair, if they are stretched that means that the follicule suffered from distress from being pulled from the follicule and that the force with which was being pulled caused a rupture in the hair follicule that made the follicular tags to stretch and eventually separate the hair from the head.
Answer:
D
Explanation:
Parasites do not directly kill their host
Answer:
A synovial joint
Explanation:
because it is highly moveable, allows for flexibility, has ligaments for stability, and has cartilage for protection of the articulating bones. ... It is a synarthrosis joint because it cannot move.
Answer:
e. bind to troponin which moves the tropomyosin.
Explanation:
Troponin (Tn) is a protein complex composed of three different proteins: troponin C (TnC), troponin I (TnI), and troponin T (TnT). This complex is found both in skeletal muscles and cardiac muscles, where TnC attaches calcium ions through four and three calcium ion-binding sites, respectively. When a muscle is relaxed, Tn attaches to tropomyosin to prevent muscle contraction. During muscle contraction, calcium channels open and cytosolic calcium ions bind to TnC, thereby Tn changes its conformation and moves the tropomyosin. This process relieves the inhibition of the interaction between actin and myosin filaments, which makes muscle contraction possible.