<span>A mature sporophyte produces spores by meiosis, a process which reduces the number of chromosomes to half, from 2n to n. Because meiosis is a key step in the alternation of generations, it is likely that meiosis has a fundamental adaptive function. The nature of this function is still unresolved (see Meiosis), but the two main ideas are that meiosis is adaptive because it facilitates repair of DNA damages and/or that it generates genetic variation.
The haploid spores germinate and grow into a haploid gametophyte. At maturity, the gametophyte produces gametes by mitosis, which does not alter the number of chromosomes. Two gametes (originating from different organisms of the same species or from the same organism) fuse to produce a zygote, which develops into a diploid sporophyte.</span>
Answer:
memerintahkan kaum muslimin untuk hijrah ke habasyah(Ethiopia)
Explanation:
-Dalam rombongan pertama hijrah, yaitu pada tahub ke lima kerasulan nabi muhammad, ada 15 orang.
10 laki lakin dan 5 perempuan yang hijrah ke habasyah dibawah komando ustman bin affan, termasuk istri ustman bin affan yaitu rukyah binti muhammad
-kemudian, pada rombongan ke dua, ada sekitar 81 orang, yang terdiri dari 80 laki laki dan 1 perempuan. perempuan tersebut adalah ummu habibah yang merupakan istri dari abu sofyan
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Answer:
(a) 1/2; (b) no
Explanation:
Glucose-6-phosphate dehydrogenase deficiency (G6PD) is an X-linked recessive disorder and the woman's father was diseased so it means that woman is a carrier of the allele but has normal phenotype. It means that she will have XXᵇ genotype.
In contrast to this, her husband is diseased so his genotype will be XᵇY.
The Punnett square diagram related to the cross is attached.
(a) Proportion of their sons expected to be G6PD is 1/2:
They both may give birth to 4 progeny with genotypes XXᵇ, XᵇXᵇ, XY and XᵇY. It means they both may have 2 sons out of which one with genotype XᵇY will be diseased while the one with genotype XY will be healthy. So the proportion of their sons having G6PD is 1/2 or 50%.
(b) If the husband were G6PD deficient, the answer will not change.
The reason behind this is that this disease is caused by an allele located in X chromosome. But father contributes only Y chromosome to his son not X chromosome. The X chromosome will affect the genotype of his daughter not son that is why answer will not change. It means they will still have 1/2 of their sons diseased.
It’s usually changes it into marble!!