Which allele combination represents a male who has an x-linked recessive disorder? xry xry xrxr xrxr

XrY

Explanation:

i guess the R shows the dominancy, R dominant r recessive where the r followes the X, meaning it is X-linked

The allele combination XrY is the allele combination of X linked recessive disorder  in a male.

Explanation:

A human male has one X chromosome and one Y chromosome which makes them heterogamous. Females have two copies of X chromosome and thus they are homogamous. Due to the presence of just one X chromosome chances for males getting affected by the disease is more.

Haemophilia and muscular dystrophy are X linked recessive disorders. Females with one affected X chromosome act as carriers but won’t  have the disease. For a female to be affected with the disease both the X chromosomes should be affected.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.