Asexual requires one parent, which produces genetically identical offspring, however sexual reproduction requires two parents, and there is a varied genes
The stomata and their guard cells allows this happen.
Stomata is like a hole or gap on a leaf, most of them are present in a bottom side of the leaf, since waxy cuticle is not present over there. And 2 guard cells make up a stomata.
Guard cells are able to control the size of the stomata, depending on the situation. For example, the guard cells close up during day time because a lot of sunlight may cause more water loss.
In conclusion, guard cells and the stomata are the main structures that allow carbon dioxide and oxygen (water too) diffuse in and out of leaves.
The correct answers are 1, 2 and 4
The hemoglobin holoenzyme (active enzyme) is a complex of an iron ion and 4 subunits- 2 hemoglobin alpha and two hemoglobin beta. People with sickle cell disease have mutated beta hemoglobins. The mutation is a single nucleotide exchange, that changes the 6th amino acid of protein primary struture - a Glutamic acid into Valine. This one alteration changes the tree dimentional structure of hemoglobin beta so, that it forms lond fibres that disrupt the normal circular form of the red blood cells.
Density dependent because the population was affected by the forest fire