So we can easily classify animals and distinguish their relationships
Answer:
Explanation:
a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.
The question is incomplete as it does not have the options which are:
I. only
I. and II. only
II. and III. only
I, II, and III.
Answer:
I, II, and III.
Explanation:
The mechanism of natural selection can be explained for the trait which is determined by one gene but the traits which can be determined by more than one gene like height (polygenic trait), the selection becomes very complex.
The natural selection can be explained by the phenotype produced in a population and that depends on the genes. The polygenic trait shows the variation in the population, therefore, it is impossible to predict only one mechanism and therefore all types of natural selection occurs on a population.
Thus, I, II, and III are correct.
Answer:
The number of STR repeats is unique and therefore it is considered as an allele of that <em>locus</em>
Explanation:
Short Tandem Repeats (STRs), also known as microsatellites or simple sequence repeats (SSRs), are short DNA sequences with a size of 1-6 nucleotide bases which may be many times repeated in tandem. STRs localize in specific regions of the genome (<em>loci</em>) and therefore they are molecular markers. Gel electrophoresis a technique used to separate DNA fragments based on their size. In consequence, the pattern of STR repeats or 'alleles' obtained by electrophoresis can be used to identify individuals. In a gel electrophoresis, STR markers produce different bands that run more slowly or faster on the gel in different lanes according to their size (e.g., more slowly >> higher size of the STR sequence), and thereby STR alleles are unique and serve to identify individuals.
