Answer:
Waldemar carried the recessive allele.
Explanation:
The carrier is the individual that has the affected allele or mutation but does not express the trait, or might express it in different levels. Although, as the person carries the mutation, she or he might transmit the genetic mutation associated with a disease to the progeny. In general, these diseases are inherited as recessive traits.
So, in the exposed example we know that:
- hemophilia is a sex-linked disorder
- hemophilia is determined by a recessive allele on the X chromosome.
- Irene is a carrier.
- Her husband is not a carrier.
- Her children Waldemar and Henry have hemophilia.
If Irene is a carrier, this means that she is heterozygous and that her genotype is X⁺X⁻ (Being the symbol + the dominant allele, and - the recessive one for that expresses the trait)
The fact that Irene´s husband is not a carrier means that his genotype is X⁺Y
Their boys Waldemar and Henry have hemophilia, so both their genotypes are X⁻Y
The best evidence to prove that Irene was heterozygous for hemophilia is that Alice carried the recessive allele.
- Alice is Irene´s Mother, and she is a carrier as well. Irene´s father, Louis, is not a carrier, so she could have inherited a dominant allele from her father and a recessive allele from her mother, X⁺X⁻, or she could have inherited two dominant alleles from both her parents X⁺X⁺. This is not proof enough of Irene being heterozygous.
- The fact that Alexandra, Irene´s sister, was also a carrier does not say anything about Irene´s genotype, because they could both share the same genotype or not. This is not proof of Irene being heterozygous.
- Frederick (her brother) was hemophilic. He received a recessive allele from Alice, but this does not say anything about Irene´s genotype.
- The fact that Waldemar (her son) was hemophilic, is the best evidence to prove that Irene was heterozygous for hemophilia. Walderman received the Y chromosome from his father and an X chromosome from his mother. The X chromosome that he received from his mother carried the recessive allele for the trait, and this is why he had hemophilia. This means that there is no best evidence for Irene´s genotype than her son´s genotype.
Answer:
C
Explanation:
Due to the erosion of soils, no trees to protect the ground from drying out.
ovary
These oocytes are formed during the early development of the person, it is together formed in the embryonic stage of development.
In puberty, these oocytes have now been mature thus, the individual is ready for her first menstruation, it takes time before these oocytes are fully developed but they are formed as early as the state of the genitalia, brain, body was formed.
<span>Somehow, it is like the brain, the brain is slowly developing til the near age of puberty or late childhood. </span>
<span>Eyes are also an analogy to oocytes, during infancy these organs aren't developed yet and these years the child can only see vague and blurred vision and takes almost 2 years for the child to see clearly.</span>
Answer: Due to crossing over and independent assortment.
Explanation: Crossing over occurs in Prophase I. It's when the homologous chromosmes switch genes with each other. This ways, genes are recombined, unique chromosmes are made!