Homozygous means "the same" and Heterozygous means "different". If a pheno type is homozygous, for example, it could be XX or xx, while heterozygous could be Xx. Hope that helps.
Photosynthesis is when plants use sunlight to synthesize food from carbon dioxide. Plants are autotrophs (they make their own food) and the food they synthesize creates carbohydrates, so the correct answer is D - autotrophs produce carbohydrates.
Hope this helps.
Counter current involves blood in the capillaries flowing in the opposite direction to the flow of water flowing over them. Gases diffuse faster from one area to another when the concentration difference between the two areas is at its greatest, as compared to when the concentration difference is low.
B ~ You cannot tell if someone was touching your hand
Hope this helps! ^^
