Answer:
Some challenges animals might face when migrating are disease, global climate change, overexploitation, and habitat destruction.
Explanation:
In virtually every corner of the globe, migratory animals face a growing array of threats, including habitat destruction, overexploitation, disease, and global climate change. Saving the great migrations will be one of the most difficult conservation challenges of the 21st century.
If reproduction didn't exist, all species would eventually go extinct.
Tropical rain forest biome :)
Answer: Promoter
Explanation:
Transcription is the first step in gene expression which consists of copying the DNA sequence of a gene to produce a RNA molecule. There are enzymes called <u>RNA polymerases which perform this process of transcription</u>. These enzymes bind nucleotides (the monomers which are part of the nucleic acids) to create a RNA strand using a DNA strand as a mold.
A promoter is a region of DNA that controls the initiation of transcription of a given portion of DNA to RNA. Therefore they promote the transcription of a gene. <u>The promoter region is composed of a specific sequence of DNA located just where the starting point of the DNA transcription is</u> and contains the information needed to activate or deactivate the gene it regulates. <u>The promoter has a binding site for the RNA polymerase enzyme </u>in charge of mRNA synthesis and when it recognizes this site, transcription begins.
It's true , because the nucleolus has always been inside the nucleus . It should be in your textbook
