Answer:
The homologous chromosomes pair together in prophase 1 of meiosis, but they do not during prophase 1 of mitosis. This is achieved by a process known as synapsis, where the similar chromosomes pair according to sequence similarity. The homologous chromosomes are held together by a protein structure known as the synaptonemal complex in a chromosome body known as a tetrad (because it contains 4 replicated chromosomes known as chromatids) or bivalent (if the organism is diploid). This pairing during prophase 1 of meiosis allows recombination to take place between the homologous chromosomes. This occurs early during prophase but the manifestation of recombination only becomes visible during the later stages of prophase 1 and in metaphase 1. Because the chromosomes adopt different structures during prophase 1 of meiosis, this stage is sub-divided into 5 stages: leptotene, zygotene, packytene, diplotene and diakinesis. It is during diplotene and diakinesis that the physical manifestation of recombination can be seen. This is the presence of chiasmata (chiasma, singular). These are the sites where recombination, or exchanges between homologous chromosomes, has taken place. By the end of prophase 1, it is only the chiasmata that holds the homologous chromosomes together. This constriction make the tetrads adopt a variety of structures, the shape of which depends upon the number of chiasmata formed. The tetrads stay in this conformation until metaphase 1. Synapsis, the formation of the synaptonemal complex, the formation of chiasmata does not take place during prophase 1 of mitosis and these processes represent the major differences between prophase of the two nuclear divisions.
.25
This is because 1/4 = .25
To find the allele frequency, you need to find the decimal representation of the fraction.
For example: If an allele makes up four twentieths of a population's alleles, then the frequency would be .2 (4/20 = .2)
Answer:
This question lacks options, the options are:
A. The sequence of DNA determines the structure of lipids, which produce phenotypes.
B. The sequence of DNA determines the structure of proteins, which produce phenotypes.
C. The sequence of DNA determines the structure of phosphates, which produce phenotypes.
D. The sequence of DNA determines the structure of carbohydrates, which produce phenotypes.
The answer is B.
Explanation:
DNA is the genetic material found in the genome of living organisms. DNA holds the information needed for the synthesis of useful products in an organism. DNA contains segments called GENES that encodes the biological molecule, PROTEINS, which is responsible for the trait exhibited by organisms.
An example of trait in humans is human color, which is encoded by DNA. However, this DNA does not directly produce hair color in humans but the information held in it undergoes expression to produce protein called MELANIN, which is responsible for the hair color trait. Hence, the sequence of DNA determines the structure of proteins, which produce phenotypes (hair color).
Answer:
Thus, in eukaryotes, while transcription occurs in the nucleus, translation occurs in the cytoplasm.
