Answer:
<u>Mitosis:</u>
A single division occurs, separating sister chromatids
End result is two diploid cells that are genetically identical to each other and the parent cell
<u>Meiosis: </u>
The first division separates homologous pairs; the second division separates sister chromatids
Homologous chromosomes pair up and form chiasmata
Homologous pairs of chromosomes line up on the metaphase plate
Daughter cells contain recombinant chromosomes
End result is four haploid cells that are genetically different from each other and the parent cell
<u>Mitosis and Meiosis: </u>
Chromosomes duplicate during interphase
Process starts with a diploid cell
Duplicated chromosomes line up Individually on the metaphase plate in a diploid cell
Explanation:
Mitosis is the division of vegetative cells while meiosis involves the division of sex cells. <u>Both divisions start with diploid parental cells</u> but while the daughter cells in mitosis are also diploid, those of meiosis are haploid. This is why mitosis is referred to as equational division while meiosis is known as reductional division.
A cell that will undergo mitosis or meiosis would first have <u>its genetic materials duplicated during interphase</u> in addition to the synthesis of other important biochemicals such as proteins. Mitosis involves just a single division of the sister chromatids with <u>two genetically identical daughter cells who are also clones of the parent cells resulting</u>.
Meiosis, on the other hand, involves two divisions - the <u>first one happens to separate homologous chromosome pairs while the second division separates sister chromatids just like in mitosis</u>. During the early stage of meiosis, homologous chromosomes synapsed through the formation of a synaptonemal complex to form tetrads. Thereafter, synapsed chromosomes <u>exchange chromosomal segments at a point known as chiasmata.</u> All these happen at the prophase stage of meiosis I. The paired homologous chromosomes are then lined up at metaphase where they are engaged by the spindle fibers.
Meiosis II and mitosis are more or less the same with the chromosomes condensing at the prophase and the formation of metaphase plates at the metaphase. Sister chromatids are pulled apart and they migrate to the opposite poles at the anaphase and telophase.
Answer:
The active transport and the facilitated diffusion both involve the proteins present in the cell membrane. Facilitated diffusion transport the large and the charged molecules through the protein transport channels present in the cell membrane
Explanation:
Answer:
Generally, mammals have a pair of bran-shaped kidneys. The mammalian kidney has 2 distinct regions, an outer renal cortex and inner renal medulla. Both regions are packed with microscopic excretory tubules, nephrons, and their associated blood vessels. Each nephron consists of a single long tubule and a ball of capillaries, known as glomerulus. The blind end of the tubule forms a cup-shaped swelling called Bowman’s capsule, that surround the glomerulus. From Bowman’s capsule, the filtrate passes through 3 regions of the nephron which are proximal tubule, the loop of Henle. A hairpin turns with a descending limb and an ascending limb and the distal tubule. The distal tubule empties into a collecting duct, which receives processed filtrate from many nephrons. The many collecting ducts empty into the renal pelvis, which is drained by ureter.
For the structure of nephron, each nephron is supplied with blood by an afferent arteriole, a branch of the renal artery that subdivides into the capillaries of the glomerulus. The capillaries converge as they leave the glomerulus, forming an efferent arteriole. It is surrounded by the Bowman’s capsule. The double-walled epithelial Bowman’s capsule is formed by the invagination of the blind end of the nephron. The glomerulus and Bowman’s capsule form the first region of the nephron and is known as the renal corpuscle or the Malpighian body. The capillary walls are composed of a single layer of endothelial cells with openings between them with a diameter 50-100nm. These cells are pressed up against basement membrane which completely envelops each capillary, separating the blood in the capillary from the lumen of Bowman’s capsule. The inner layer of the Bowman’s capsule is composed of a cell called podocytes which have arms that give off structures resembling tube-feet called foot processes or secondary processes. The secondary processes support the basement membrane and capillaries beneath it and gaps between the processes (slit pores) facilitate the process of filtration. The Malpighian body leads into the remainder of the tubule.
Answer: I'm pretty sure B is correct.
Explanation:
yeah
* More than 40 proteins and glycoproteins involved in the complement system are synthesized by the liver, macrophages, epithelial cells, they are present in the blood in plasmatic form, membrane, some have an enzymatic activity, regulator or membrane receptorThese are elements of the humoral innate immune response, they fight infections, purify immune complexes and apoptotic bodies.
<span>There are indeed three ways to activate the complement:</span>
Classical pathway: Activated by Immunoglobulins in immune complexes, aggregated Immunoglobulins, DNA, CRP, apoptotic bodies .......it involves nine fractions, starting with C1, then C4, C2, C3, to form a classical C5 convertase, then, activation of C5, C6, C7, C8, C9.
Alternative pathway: activated by polysaccharides (bacterial endotoxin), vascular wall poor in sialic acid, aggregated IgE ...C3b like is the first component in the alternate channel cascade, it will create an amplification loop, and form an alternative C5 convertase.
Lecithin pathway: Activated by mannose, fucose (carbohydrate of microorganisms)The first component is the complex MBL / MASP1 / MASP2: "mannose-binding protein": works according to the same principle as the complex C1 of the classical way (MASP2 cleaves the C4 and the rest of the cascade is equivalent to that of the classical way).
the three ways have the same outcome: A C5 convertase (formed by one of the pathways) cleaves C5 into C5a and C5b: C5b is deposited far from other fractions on the antigenic surface. The fixation of C5b in the cell is followed by that of C6, C7, C8, and C9 (9 molecules of C9): formation of the membrane attack complex (MAC) ==> Death of the cell by osmotic shock
