Both Gram-positive and Gram-negative bacteria commonly have a surface layer called an S-layer. In Gram-positive bacteria, the S-layer is attached to the peptidoglycan layer. Gram-negative bacteria's S-layer is attached directly to the outer membrane). Specific to Gram-positive bacteria is the presence of teichoic acids in the cell wall
However, there are cases where the color may appear yellowish, sometimes referred to as âyellow spermâ or âyellow semenâ. The cause of yellow sperm is uncertain but it is believed that it can be caused by infection, or foods which are rich in sulfur such as garlic and onions.Another possible cause for yellow semen could be the natural thickening of semen; especially if you have not ejaculated for quite some time.he cause of yellow sperm is uncertain but it is believed that it can be caused by infection, or foods which are rich in sulfur such as garlic and onions.
X Y. 0.050. Assuming that the X and Y-bearing sperm are produced in an equal ratio, then 50% (0.5) of the sperm carry the Y chromosome and 50% (0.5) of the sperm carry the X chromosome. Since a small percentage of the X-bearing sperm carry the recessive color-blind gene, their numerical value is 5% (0.05). Y. In the above cross, four different possible offspring are produced: X Y: Color-blind Boy (1/4 or 25%) X+Y Normal Vision Boy (1/4 or 25%) X X Color-blind Girl (1/4 or 25%) X+X Heterozygous Normal Vision Girl (1/4 or 25%) Note: The heterozygous normal vision girl carries the recessive gene for color blindness.