Descending tracts are the pathways by which motor
signals are pass through from the brain to lower motor neurones. Thus, all
the neurones within the descending motor system are classed as upper motor
neurones. The lower motor neurones then directly innervate muscles to produce
movement. Their cell bodies are found in the cerebral cortex or the brain stem,
with their axons remaining within the CNS.
Conception is necessary for the continuation of species...for reproduction.
Answer:
a. maple leaf and oak leaf
Explanation:
Homologous structures are those that have the same evolutionary origin but fulfill very different functions, a good example could be the wing of a bird and the wing of an insect, the wings of birds, are modified front members and the wings of insects are "BRANCHES" modified
In the case of maple and oak leaves they are homologous structures because they have a common ancestor according to their genetic decoding, that is, even if they can look different or behave differently, they are genetically homologous structures.
The answer I would choose is c
Bone Marrow is tissue in the hollow centers of our bones, it has stem cells which produce our blood cells. It also produces red blood cells that give oxygen to the whole body. Hope this helped : )