Hello, can someone please help me with this question or explain what the answer would be and how it would be drawn :)

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

Put the following processes of protein synthesis in the correct order: - dna strands unwind and separate - mrna copies dna according to complimentary base pairing - trna's anticodons bring amino acids to the corresponding mrna codons - amino acids bind to each other making a protein - mrna leaves the nucleus - a stop codon is reached, the newly formed protein is released to go do its job for the cell

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important