Answer:
Ss (male) × Ss (female)
Explanation:
This question involves a single gene coding for hair length in guinea pigs. Based on the information in this question, the allele for short hair (S) is dominant over the allele for long hair (s). This means that a guinea pig will only be phenotypically long-haired if the genotype is "ss".
According to this question, Two short-haired guinea pigs are mated several times. Out of the 100 offsprings produced by this cross, 25 of them have long hair (recessive). This means that the phenotypic ratio of this cross is 3 short hair : 1 long hair i.e. 100 - 25 = 75 short hair. 75/25 = 3/1 = 3:1
To produce this phenotypic ratio, the parents must both be heterozygous (Ss) for the hair length gene.
FSH is secreted by the Pituitary Gland... upon GNRH being secreted by the Hypothalamus.
Answer:
Some forms of chromatin modification can be passed on to future generation of cells
Acetylation of histone tails in chromatin allows access to DNA for transcription
DNA is not transcribed when packaged tightly in a condensed form
methylation of histone tails can promote condensation of the chromatin
Explanation:
chromatin modifications that can be passed on includes epigenetic modifications that are heritable changes made to the chromatin structure that does not involve the DNA sequences. Some epigenetic modifications include DNA methylation and Histone modifications. examples of histone modification include acetylation, methylation, phosphorylation, ubiquintylation etc. All these function either in allowing the DNA become more accessible to transcritional factors or vice versa. for exmple, histone tail acetylation encourages unwounding of nucleosomes allowing transcriptional factors to have access to the DNa while histone tails methylation further tightens the nucleosomes promoting condensation of the chromatin.
The second stage of prenatal development begins at about two weeks after conception. at this point, the growing bundle of cells is called an embryo.
