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.
Urine differs in composition from the fluid that first enters a nephron tubule by filtration because <u>filtrate has more salts because of reabsorption and secretion</u>.
Filtrate is the liquid that is formed in the kidneys while urine formation is taking place. Water is the major component of urine, forming about 95% of it while the remaining part is formed by other organic and inorganic constituents.
As blood flows through the glomerulus, blood pressure pushes water and solutes from the capillaries into the capsule through a filtration membrane.
To learn more about composition of urine in the first stage of nephron tubule, here
brainly.com/question/14137464
#SPJ4
Answer:
31. Seatbelts lock in place to make sure you don't go flying into the windshield.
32. Friction causes the soccer ball to slow down. If we were to kick a soccer ball in space, where there is no friction, it would keep on rolling until it eventually hits something or goes out of sight.
33. Heavier loads will make the vehicle move off of the table. The heavier the weight, the quicker the vehicle will roll. Loads that are something very similar or lighter than the vehicle won't make the vehicle move by any means.
34. Gravity is the power pulling the piano toward the Earth.
Friction would happen with an unpleasant surface, making it a lot harder to push the piano up the ramp.
35. Wagon C
Wagon C has the least boxes and minimal measure of mass, making it simplest to move.
36. I would move the crates so every cart has a similar measure of boxes, making them equivalent in mass. This would make them all take a similar measure of power to move them.
Explanation: I have the answer key
Answer:
See the answer below
Explanation:
Normal height - H
Short height - h
Heterozygous - Hh
A cross involving heterozygotes would be Hh x Hh
Hh x Hh
HH Hh Hh hh
Since H is dominant over h;
HH and Hh would produce normal height phenotypes.
hh will produce a short height phenotype.
Thus;
<em>Probability of normal height phenotype resulting from the cross = 3/4 or 75%</em>
<em>Probability of short height phenotype resulting from the cross = 1/4 or 25%</em>
