Can certain diseases be hereditary?
Are genetic disorders passed though DNA?
Can we predict certain diseases based on certain chromosomes?
Answer:
1/8 (12.5 %)
Explanation:
Cross: IAi X IAIB
F1: 1/4 IAIA 1/4 IAIB 1/4 IAi 1/4 IBi
Phenotypes:
- IAIA and IAi >> type A blood
- IBi >> type B blood
- IAIB >> type AB blood
Phenotypic frequency type A blood: 1/2 (i.e., 1/4 IAIA + 1/4 IAi) >>
Probability to have 3 offspring with type A blood: 1/2 x 1/2 x 1/2 = 1/8
The human ABO blood group is a system consisting of there different alleles: A, B, and O. This system is used in genetics as an example of codominance because both A and B alleles are expressed in heterozygous individuals (i.e., IAIB), whereas only the allele A is expressed in individuals that have A and O alleles (since O allele is recessive to the A and B alleles).
Synapsis:
•Early
during the first nuclear division.
•Homologous
chromosomes pair along their length.
•Held
tightly by protein ‘zipper’.
<span>Homologous Recombination: </span>
•Genetic
exchange (crossing
over<span>)
occurs between homologous chromosomes. It then becomes a mix of both paternal and maternal genes (father and mother respectively)</span>
The answer is A.
Twins form in one of two ways:
Identical twins occur when a single fertilized egg splits into two.
Fraternal twins occur when two, separate eggs are fertilized by two, separate sperm.
Answer:
Option a is the one, that is true.
Sister chromatids separate in anaphase of mitosis and anaphase Il of meiosis
Explanation:
After the interphase in the cell division cycle, the mitosis process begins, which is composed of 4 phases, prophase, metaphase, anaphase and telophase. The prophase occurs when the chromatin is condensed and the mitotic spindle is formed, the metaphase the chromosomes align along the cell equator, in the anaphase the separation of the sister chromatids occurs and in the telophase finally the heterochromatin is converted into euchromatin and the envelope is formed nuclear cell.
Meiosis, which is the cell division of germ cells, also has the same phases but they occur on two occasions: prophase I, metaphase I, anaphase I and telophase I for meiosis I and for meiosis II, prophase II, metaphase II, anaphase II and telophase II. In the anaphase I the homologous chromosomes are separated, they are condensed in the prophase II while in anaphase II the chromatids are separated.
