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

The right answer is XrY.

Men, who have only one X chromosome, have the disease if they carry an abnormality on their only copy of the gene. The Y chromosome carries genes different from those carried by the X chromosome.

In genetics the uppercase letters designate a dominant allele and the lowercase letters designates a recessive allele, which lets us say that the answer is XrY.

answer: grassland biomes are closer to the equator and receive more rain.

grasslands are biomes that are dominated by grasses rather shrubs and trees. savanna are biomes that exhibit grasses, shrubs and small tree as vegetation. grasslands are located near the equator of the earth. these are found in north america. savanna biomes are found in africa, south america, australia and india. grassland exhibit moderate climatic conditions, it receives   amount of rainfall higher than savanna.   therefore, savanna exhibit dry and hot climatic conditions.