The two strands of dna are hold together by

Biology

1 answer:

yulyashka [42]3 years ago

5 0

Answer:

Weak hydrogen bonds and Covalent Bonds

Explanation:

The DNA double helix is held together by two types of bonds, covalent and hydrogen. Covalent bonds occur within each linear strand and strongly bond the bases, sugars, and phosphate groups (both within each component and between components). Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing. These hydrogen bonds are individually weak but collectively quite strong

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Pharmacist are experts in medicine. Which branches of science do pharmacists need to know in order to do there job properly?

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The answer would be Biology and Chemistry. Although they do use a little bit of physics, it's mostly chemistry and biology.

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Natural selection is based on Darwin’s observation that individuals most likely to survive and reproduce are those _____.

mariarad [96]

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Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive allele in humans. A woman whose father

prohojiy [21]

Answer:

(a) 1/2; (b) no

Explanation:

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is an X-linked recessive disorder and the woman's father was diseased so it means that woman is a carrier of the allele but has normal phenotype. It means that she will have XXᵇ genotype.

In contrast to this, her husband is diseased so his genotype will be XᵇY.

The Punnett square diagram related to the cross is attached.

(a) Proportion of their sons expected to be G6PD is 1/2:

They both may give birth to 4 progeny with genotypes XXᵇ, XᵇXᵇ, XY and XᵇY. It means they both may have 2 sons out of which one with genotype XᵇY will be diseased while the one with genotype XY will be healthy. So the proportion of their sons having G6PD is 1/2 or 50%.

(b) If the husband were G6PD deficient, the answer will not change.

The reason behind this is that this disease is caused by an allele located in X chromosome. But father contributes only Y chromosome to his son not X chromosome. The X chromosome will affect the genotype of his daughter not son that is why answer will not change. It means they will still have 1/2 of their sons diseased.