Which of these cell junctions form a barrier to the passage of materials?

Chinese privet is a plant that is native to china. over 150 years ago, chinese privet was introduced to the united states as a fast-growing shrub that serves as an excellent privacy hedge. with no natural herbivore, chinese privet quickly established itself and spread in natural areas throughout the southeast and eastern seaboard of the united states. its dominance in these areas has jeopardized the survival of native plant species. chinese privet provides evidence that introducing non-native organisms can cause environmental damage integrated pest management strategies will not decrease chinese privet populations american gardeners can easily control the spread of chinese privet non-native plant species have type i survivorship curves

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

The rapid decomposition of organic matter produces evidence which supports: the slow accumulation of coal deposits long ages of the earth rapid burial of vast amounts of vegetation biblical account of noah's flood