How do spring tides and neap tides differ , what causes them ?

A spring tide is when the difference between a low and high tide is the greatest while a neap tide is when the difference between the low and high tide is the lowest. 

Spring tides occur during the full or new moon, and when the moon, Earth, and the sun are aligned. The collective gravitational pull on the Earth's water is strengthened during the alignment of the moon, Earth, and the sun.

Neap tides occur when the moon and the sun are at the right angle to the Earth, which occurs twice a month. The total gravitational pull on the Earth's water during this time is lesser since the gravitational pull comes from two different directions. 

answer; i believe the correct answer is (anemia);

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.