Answer: A. The genes encode resistance to antibiotics.
D. The genes are carried on plasmids
F. The "clock"genes are highly mobile between species.
Explanation:
Molecular clock is a tool that is used to calculate the time of the evolutionary events. These are the gene sequences that are used to determine the evolutionary distance between the new and primitive organisms developed on earth. It also measures the random changes just like mutation. Thus the molecular clock is also called as the gene clock or evolutionary clock.
The accuracy of the molecular clock can be increased by the genes that encode for a resistance against the antibiotics, the genes that are carried on the plasmids and the clock genes which are highly mobile among the species.
Answer:
Nucleus
Explanation:
Prokaryotes are the organism that came earlier than eukaryotes on this earth. These prokaryotes do not have a nucleus and other membrane-bound organelles like chloroplast, mitochondria, Golgi apparatus, endoplasmic reticulum, etc.
So as prokaryotes lack membrane-bound organelle their genetic material is not enclosed in the nucleus therefore their genetic material remains in the cytoplasm of the cell while eukaryotes have membrane-bound nucleus in which their genetic material are present.
So the nucleus is the major organelle that prokaryotes are missing that eukaryotes have.
Answer: a. Genetic recombination (crossing over)
b. Can also be explained in terms of crossing over
c. Non disjunction of homologous chromosomes in meiosis 1
Explanation:
The process that allows for the transfer of both the paternal and maternal materials to is the crossing over process that takes at meiosis 1 changing them to secondary spermatocytes. While they are still primary spermatocytes, they are still diploid cells having both the maternal and paternal chromosomes. But since the spermatozoon is an haploid cell, it is able to retail some of both parents chromosome by the crossing over event which takes place between homologous paternal and maternal chromosomes allowing them to exchange materials. Thus the chromosomal contents of the primary spermatocyte differs from that of the spermatozoon.
C. This can occur as a result of the one of the homologous chromosome pair refusing to separate at meiosis 1 with one gamete containing 4 chromosomes/8 sister chromatids and the second having 2 chromosomes/4 sister chromatids.
Answer:
Typically, the nucleus is the most prominent organelle in a cell (Figure 1). The nucleus (plural = nuclei) houses the cell's DNA in the form of chromatin and directs the synthesis of ribosomes and proteins.
Explanation:
