Scientists believe that ancient ancestors of all animals were single celled eukaryotes that sometimes grew in colonies. The correct option among all the options that are given in the question is the second option or option "B".
The Cambrian Explosion resulted in the evolution of the first representatives of most animal phyla. The correct option among all the options that are given in the question is option "B".
The intervertebral discs, which are between vertebrae, are the parts that prevent the vertebrae from grinding against one another.
The intervertebrals discs act as a cushion; they absorb the stress and shockw that occur during movement, preventing such grinding.
A mistake in DNA replication before meiosis produces an organism that is better able to outrun predators.
Explanation:
The genetic variation results from the different alleles of a population. The mutation or mistake in DNA replication would cause gene variants which may be beneficial. The variation in the DNA sequence of genome results in variants in small population.
Genetic variation is the cause of natural selection and eventually, evolution takes place with beneficial traits.
It is mentioned in the question that resulting offspring having received the mutant allele could result in better surviving capabilities or phenotypic traits as they are able to outrun predators.
Answer:
1. Purines
2. States that DNA composition varies among species
3. Hydrogen Bond
4. Purines
<em>Answer to #2 is a little iffy </em>-- sorry
Explanation:
Pyrmidines have two rings
Purines have one ring
Complementary bases are connected by hydrogen bonds.
