Answer;
B) four chromosomes
Explanation;
-Mitosis is a type of cell division that involves nuclear division in eukaryotic cells and occurs when a parent cell divides to produce two identical daughter cells.
-Mitotic cell division produces two daughter cells that are genetically identical to each other, and to the parental cell. Thus, a diploid cell, 2n, (contains two sets of chromosomes), yields two daughter cells that are also diploid.
-For example, in human beings, mitosis takes place in the somatic cells where a parent cell with 46 chromosomes produces two daughter cells each with 46 chromosomes.
Answers: examples of host defence mechanism include: Innate anatomical and physiological barriers, Innate cellular and chemical defenses.
Explanation:
The capability of the human body to resist almost all types of organisms or toxins that tend to damage the tissues and organs is known as IMMUNITY. This host defence mechanism can be classified into INNATE or adaptive immunity.
The immunity that results from general processes, rather than from processes directed at specific disease organisms is called the INNATE IMMUNITY. The anatomical and physiological barriers of the innate immunity provides the first line of defence against pathogens. Examples of these barriers of the innate immunity includes:
--> Destruction of swallowed organisms by the low stomach pH and digestive enzymes
--> The vigorous mucociliary clearance mechanisms of the respiratory airways and lungs.
--> Resistance of the skin to invasion by organisms
While examples of innate cellular and chemical defenses include:
--> Phagocytosis of bacteria and other invaders by white blood cells and cells of the tissue macrophage System
--> lysozymes, a mucolytic polysaccharide that attacks bacteria and cause them to dissolute.
--> basic polypeptides which react and inactivate certain types of gram- positive bacteria
-->natural killer lymphocytes that can recognize and destroy foreign and tumor cells.
Answer: D
Explanation: the image shows this. Let me know if I’m right.
Answer:
The fork is drawn to emphasize its similarity to the bacterial replication fork depicted in Figure. Although both forks use the same basic components, the mammalian fork differs in at least two important respects.
First, it uses two different DNA polymerases on the lagging strand.
Second, the mammalian DNA primase is a subunit of one of the lagging-strand DNA polymerases, DNA polymerase α, while that of bacteria is associated with a DNA helicase in the primosome. The polymerase α (with its associated primase) begins chains with RNA, extends them with DNA, and then hands the chains over to the second polymerase (δ), which elongates them. It is not known why eucaryotic DNA replication requires two different polymerases on the lagging strand. The major mammalian DNA helicase seems to be based on a ring formed from six different Mcm proteins; this ring may move along the leading strand, rather than along the lagging-strand template shown here.
Reference: Molecular Biology of the Cell. 4th edition. Alberts B, Johnson A, Lewis J, et al. New York: Garland Science; 2002.
