The right answer are all the three of them (1, 2 and 3).
Let's compare between a normal cell culture and a cancer cell culture:
- Normal or defined cultures: the cells only multiply during a limited number of degenerations (30 to 50 subcultures) then die: their life and their death is programmed. We then observe a decrease in their rate of proliferation, phase of senescence.
- Continuous culture or transformed or immortal lineages. The multiplication speed does not decrease (reproduction without limits, non-stop), which allows an indefinite number of subculture. The cells constituting these cultures lose the contact inhibition and grow in clusters or multilayer (multiple layers).
Femur which is the thigh bone is the strongest largest and longest bone of human skeleton
There are two types of agricultural crop residues<span>. </span>Field residues<span> are materials left in an agricultural field or </span>orchard<span> after the crop has been </span>harvested. These residues include stalks and stubble (stems<span>), </span>leaves<span>, and </span>seed<span> pods. The residue can be ploughed directly into the ground, or </span>burned<span> first. Good management of field residues can increase efficiency of </span>irrigation<span> and control of </span>erosion<span>. </span>Process residues<span> are materials left after the crop is processed into a usable resource. These residues include </span>husks<span>, seeds, </span>bagasse<span>, </span>molasses<span> and </span>roots<span>. They can be used as animal </span>fodder<span> and </span>soil amendment<span>, fertilizers and in </span>manufacturing<span>.</span>
See video by Richard Dawkins in link. One of the great minds in the study of evolution. In my opinion, a more significant figure than Darwin.