Recent content by Stephen1993

sorry about then “A diploid embryo that is homozygous for a large deletion (or has a single Xchromosome with a large deletion, in a male) is usually missing a number ofessential genes, a condition that is ordinarily lethal.” What does “A diploid embryo that is homozygous for a large...

thank you for that because the centromere attaches the chromatids together then if the centromere is deleted then the spindle cord/fibre can't pull the whole replicated chromosome but only pulls one of the chromatids? or is the spindle fibre attach to the centromere which means that if the...

thank you for that “Errors in meiosis or damaging agents such as radiation can cause breakage ofa chromosome, which can lead to four types of changes in chromosome structure (Figure 15.15). A deletion occurs when a chromosomal fragment is lost. The affected chromosome is then missing certain...

thank you for that Pg 297) “As a consequence of the independent assortment of chromosomes during meiosis, each of us produces a collection of gametes differing greatly in their combinations of the chromosomes we inherited from our two parents. Figure 13.11 suggests that each individual...

hello again this is about mitosis and meiosis what does "synapsis of homologous chromosomes" mean? does not occur in mitosis and occurs during prophase I along with crossing over between non-sister chromatids; resulting chiasmata hold pairs together due to sister chromatid cohesion for...

thank you for that pg 242 Loss of cell cycle controls in cancer cells "They may make a required growth factors themselves, or they may have an abnormality in the signalling pathway that conveys the growth factor's signal to the cell cycle control system even in the absence of that...

thank you for that is there crossing over between the sex chromosomes? XX chromosomes in females and XY chromosomes in males? thank you

thank you for that guys Specificity of viruses “For example, the HIV virus attaches to a protein, called CD4, which is found on the surface of human helper T cells. The bacterial virus lambda uses its tail to attach to an E. coli protein whose job is to transport maltose sugar into the cell.”...

thank you for that well i have studied the stuff before but now i would like to ask some questions that i don't get before Steps in endosymbiotic theory "would be the engulfing of a photosynthetic prokaryote (cyanobacterium), the precursor of the plastids including the chloroplasts."...

sorry about that the repressor protein is made constitutively means that it is produced ALL of the time.

thank you for that so it this something to do with the repressor protein made constitutively? thank you

hello sorry but i got an urgent desperate question i want to ask because this is very important! About the regulation of gene expression in bacteria What does it mean that in a repressible operons that the default state is ON? and the opposite for inducible operons what does default...

i thought so well thank you for that next question: "During anaphase, the region of overlap is reduced as motor proteins attached to the mircotubules walk them away from one another, using energy from ATP." i really have trouble with this as i am not sure what they originally mean by the...

sorry if i haven't made this clear this is the whole paragraph from a particular textbook "But there is a problem because AUG is the only codon that specifies methionine. How are the start codon AUG and internal methionine AUG codons distinguished? In eukaryotes, the initiator AUG is simply...

thank you for that but what i was really after was "How are the start codon AUG and internal methionine AUG codons distinguished." what does it exactly mean? does it mean that methionine is an amino acid in the chain? or something else? thank you