Answer: Answer is below in the explanation.
Explanation:
As shown in the animation from my school, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin, in turn, loops and folds with the help of additional proteins to form chromosomes.
(Link my school used https://www.biointeractive.org/classroom-resources/how-dna-packaged )
Answer:
The correct answer is option B. "Site-specific recombination involves two defined sequence elements, whereas transposition involves the movement of a specific sequence to a nonspecific site in the DNA".
Explanation:
Site-specific recombination is a type of genetic recombination that involves two defined sequence elements. The recombination is catalyzed by Site-specific recombinases (SSRs) that recognizes and binds to the short DNA sequences that are recognized. On the other hand, transposition is a type of genetic recombination that involves the movement of a specific sequence to a nonspecific site in the DNA. Transposition is mediated by transposases, a large super-family of enzymes from both prokaryotes and eukaryotes.
Answer:
25%
Explanation:
The female with brown teeth had a father with normal teeth. Since normal teeth is a recessive trait, the father would have been homozygous recessive for the trait and would have transmitted one recessive allele to the female. Therefore, the female is heterozygous dominant for brown teeth.
Let's assume that the allele for brown teeth is X^B while the one for normal teeth is X^b. The genotype of heterozygous dominant female would be X^BX^b and that of the male with normal teeth would be X^bY.
A cross between X^BX^b and X^bY gives progeny in following phenotype ratio= 1/4 daughter with brown teeth: 1/4 daughter with normal teeth: 1/4 son with brown teeth: 1/4 son with normal teeth. Therefore, the probability of having a daughter with brown teeth is = 25%
The correct answer is that a butterfly and an octopus do not have Carnegie stages of development, while elephants and turtles do. This is because Carnegie stages of development are stages found only in the development of the vertebrate embryo. Carnegie stages can be defined as a system in embryology, which include 23 stages of the embryonic development, each characterized with the different age, size and morphologic characteristics of an organism.