What characteristic about the tundra biome listed below does not contribute to a reduction of carbon dioxide on earth? a. nutrient-poor soil b. permafrost c. plants and their trapped carbon dioxide are frozen in the earth d. carbon dioxide sink

a. nutrient-poor soil

Tundra is the coldest biome on planet earth. It is located mainly in the Arctic region. Tundra biome functions as a sink of atmospheric carbon dioxide. This region undergoes rapid thawing and freezing. Usually, freezing occurs in the upper layers of soil and in deeper layers decomposition of dead plants and animals takes place. This facilitates the creation of organic matter source, which can be utilized by the plants for their growth under suitable conditions.  Nutrient-poor soil will not be able to decompose the dead remains, at desired rate. Therefore, will not be able to contribute to a reduction of carbon dioxide on Earth.

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.