Why do all Karens have breathing problem when it comes to wearing masks

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

In what for do plants utilize nitrogen? why do they need nitrogen?

Anita thinks that she has heterozygous alleles for red hair. if she is correct, which of these diagrams best illustrates anitas alleles pf red hair