Answer:
(a) Allow movement in only one plane/direction (that is extension or flexion)
(b) The skeletal system also produces blood cells in their bone marrow
Answer:
A.
Explanation:
bacteria have cell membranes to mimic a normal cell. this protects the bacteria from being consumed by the body's natural defences .
80 chromosomes (40 pairs)
Xylem is a very useful tissue in plants used for transportation of water from roots of a plant to its upper part for its proper growth
Answer:
abiotic factors refer to non-living physical and chemical elements in the ecosystem like water, air and sunlight.
biotic factors are living ot once-living organisms in the ecosystem like humans and animals
basically biotic is alive and abiotic is not alive
