An reaction that releases energy into the environment.
The enthalpy change (energy taken in for bond breaking of reactants - energy released for bond forming of products) can be used to determine whether a reaction is exothermic or endothermic. Since an exothermic reaction has a negative enthalpy change, it means it releases more energy than what it takes in. Hence the third statement is correct.
Im, sorry, what is the question here? I want to help you as much as I can, but I do not understand the question.
Answer:
Basal Layer
Explanation:
The epidermis contains a variety of cells. Most of the cells are keratinocytes, which are formed by division of stem cells in the basal layer.
Answer:
Genes aren't eradicated from natural selection, but the chances of getting the phenotypes (the physical attributes of an organism based on the genes) go down as the organisms with those phenotypes die out.
Explanation:
Recessive genes are still present in, for example, a heterozygous genotype. but since there is a dominant, it covers the recessive gene and the phenotype won't have anything to do with the recessive gene (unless we are talking about incomplete or codominance).
DNA replication requires a few things:
1. a template
2. DNA polymerase
3. some sort of primer which binds to the DNA to get it started
4. oligonucleotides (to add as the replication occurs)
5. a ligase to complete any fragmented DNA
So, if the biochemist added some stuff but doesn't really get replication to occcur, he/she probably left out the DNA ligase