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.
Answer:
A. Homeostasis allows organisms to regulate their temperature.
Explanation:
Homeostasis is a biological process through which the body of organisms try to maintain a relatively stable body conditions irrespective of the changes in the external environment.
<em>Homeostasis keeps body processes such as temperature, pressure, hydration, pH, etc. relatively stable. While some organisms maintain a stable body temperature by generating heat (endotherms), others do so by adjusting their body temperature to be in tune with that of the external environment (ectotherms). </em>
The correct option is A.
When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared. When there is more volume and less surface area, diffusion takes longer and is less effective.
So both the rabbits are Bb which means there will be a chart which comes out with one BB, Two Bb and one bb, For the rabbit to become brown fur it would need to get bb from theirs parents reproducing, if it's Bb they will just carry the trait recessive trait again and if it's BB they won't be carrying the trait
