If crossing over would occur how many gametes would be produced and what are they?
343366
crossin over doesnt change amount of gametes, it simply involves the exchange of genes between chromatids, it results in genetic diversity. gametes are not the chromosomes but rather the sex cells like sperm or eggs and those are haploid. meaning they have one half amount of required chromosomes. this is how evolution and genetic diversity is achieved in most sexually reproducing species
619227
Crossing Over. They form Tetrads and the tips on both ends switch.
834627
meiosis ensures that each gamete is a haploid (i.e. has half, or n, chromosomes of a normal cell). when the gametes fuse the zygote becomes 2n like a normal cell. Mitosis produces daughter cells which both have 2n, and these cannot be present in the gametes or else the zygote would have 4n!
463700
Contrast:\n- Asexual reproduction is done with only one individual or cell in the process (called mitosis) and usually involves splitting or grafting of the original organism.\n- Sexual reproduction occurs when one cell fertilizes another (sperm and egg are the most common terms for it) and it usually results in a more stable gene pool because more chromosome combinations are possible.\n\nCompare:\n- They both involve reproduction at the cellular level.\n- They both involve some manner of genetics (either splitting or joining)\n- They both produce offspring.
784408
Chimeras are formed from four parent cells (two fertilized eggs or early embryos are fused together) or three parent cells (a fertilized egg is fused with an unfertilized egg or a fertilized egg is fused with an extra sperm). Each population of cells keeps its own character and the resulting animal is a mosaic of mis-matched parts. An analogy is two jigsaw puzzles cut using an identical cutter, but with different pictures. A single puzzle can be made out of the mis-matched parts, but the completed puzzle will show parts of both different pictures. The likelihood of a child being a chimera is increased if the child is created via in vitro fertilization. Chimeras can often breed, but the fertility and type of offspring depends on which cell line gave rise to the ovaries or testes.
903177
Take each of the three traits seperately and compare to expected mendalian ratios. (Testcross means the male was completely recessive. If the female is a heterozygote then the expected ratio is 1:1, if homozygous dominant 1:0, if homozygous recessive 0:1). \n\nFor example\n243+241+15+10=509 black (1000/509=2)\n235+226+12+18=491 not black (2)\n==>approximately 1:1\nThe female had to be Bb because both types are visable.\n\nscarlet =491\nnot scarlet=509\n==>1:1, STst\n\nhooked=514\nnot hooked=486\n==>1:1, HKhk\n\nFemale is B b, ST st, HK hk\n\nFor linkage/mapping distance, take the total progeny that do not look like either parent and had to come from a crossover event and divide by the total number of progeny. Assume that the combinations you see most often are parental  (243+241+235+226). Work with two traits at a time. Significant deviation from mendalian ratios indicates linkage.\n\nb and st\nBST(parental)=235+18=253\nbst(parental)=243+10=253\nBst=226+12=238\nbST=241+15=256\nparental=506, recombination=494...approximately1:1 no linkage \n\nb and hk\nBHK=12+18\nbhk=15+10\nBhk(parental)=235+226\nbHK(parental)=243+241\nparental=945, recombination=55   \n55/1000=.055(100)=5.5cM between b and hk\n\nYour map distance is cM.
971621
"A" is the answer.  It happens in prophase of meiosis 1 and it does exactly what choice "A" states.  The rest of the choices happen during meiosis as well, but do not explain the importance of crossing over.
855495
very simple\n\nBecause sexual reproduction involves 2 species(man and woman) which entails 2 different genetic make-up. Therefore,\nthe offspring that will be produced will be based from the resulting gene of the mother and the father\n\nwhile asexual reproduction do not involve a 2nd party and so naturally it will produce another organism which is identical since it is organically within its genetic make-up
1003518
First question. If you mean sexual interciurse then of course, IVF (AI) etc\nBut as this is biology then ill assume you mean syngamy between gamets. \nIn which case the option is cloning which is not established as viable in humans yet (Korean research is under fraud investigation so its validity unclear at present) but is not permitted in most countries anyway.\n\nAs to the second question:- NO\nAsides one alleged and unlikely case (the virgin birth of mary yielding jesus christ which if it was true (unlikely) was a dead end as it was a male), parthenogensis (asexual reproduction) has never been reported in humans. Morever it is very unlikely to be viable or to occur due to imprinting etc.
695765
During s-phase of interphase, the genetic material is duplicated.    So #1 is FALSE.\n\nTelophase sees the production of the nulear membrane.  So in effect, new nuclei are formed, making #2 TRUE.\n\nMitosis creates two daughter cells that are diploid, because it is reproduction of somatic (body cells), no production of gametes (which would be haploid).  So, #3 is TRUE\n\nChromosome find their homolougous pair during prophase of Meiosis, NOT mitosis.  Pairing occurs during meiosis so the the gametes that are haploid can be formed. So #4 is TRUE\n\nEach species has a specific number of chromosomes- fruit flies for example have 8 chromosomes, while humans have 46.  So #5 is TRUE.
878913
23.  Each chromosome will be paired with its homologous partner to form a tetrad in Prophase 1.  Since the human body has 46 chromosomes and since each will pair with its homologue there will be 23 tetrads present.
1182923
Just one. \n\nVery few animals produce more than one offspring per egg.
973149
Asexual reproduction  as opposed to the sexual reproduction you and I know..  Usually happens in bacteria through a process known as binary fission.
943885
if you take the numbers one-by-one: 25! / ( (25-1)!*1! )\n\ncombination from n numbers taken by k:  n! / ( (n-k)!*k! )\n\nfor example:\n    -25 numbers, taken by 7: 25! / (18!*7!)\n    -25 numbers, taken by 4: 25!/ (21!*4!)
977774
each diploid organism receives two sets of chromosmes (one from the mother and one from father). during the reproduction of gamete cells, they go through meiosis which results in haploid cells (or cells with only half the number of a full set that a diploid organism would have). During fertilization, the two cells (egg and sperm) combine to give you a full set. (ex. your mother's egg and father's sperm each contain 23 chromosomes and came together to form a normal human with 46 chromosomes) That is why sex cells are always haploid.\n\nMathematically, if you think about it, its always something times 2 (in the previous example 23 * 2) thus the answer will always be even and a diploid organism will always have an even number of chromosomes
617905
First of all we have 23 pairs of chromosomes (or 46 chromosomes), and monkeys have  22 pairs of chromosomes. Big deal right? WRONG. When humans make gametes (sperm and egg) each gamete contains a one copy of the hosts DNA, therefore each gamate only contains 23 chromosomes. When the sperm reaches the egg they combine together (zygote) to from a cell that has 46 chromosomes. Any deviation from this number makes the an embryo inviable. ( we wont get into ploidy or trisomys here). Therefore if a human and an ape mated, the chromosome count coming from the human would be 23 and the money would be 22 making the chimera have 45 chromosomes. First of all essential genetic coding inforemation is lost. (AN ENTIRE CHROMOSOME IS MISSING), you have changed the specie. You have created an alleuploidy. (only viable with some plants). The chromosomes in each species are of different sizes. This totaly screws up the cellular functions and inhibits a proteins job. They would not be able to reproduce. And please do not get me started on Mullers moprhs in terms of loss of genetic information, regarding epistasis, incomplete dominance etc.... All you need to know is it would be inviable because the chromosomes are of different numbers, and the chromsome sizes are different.
975697
You would get two different genotypes and phenotypes.\nIf you were crossing a tall, heterozygous plant, Tt with a short plant, tt, you would get 50% Tt and 50% tt.