Answers>Biology>A Level>Article

How are polynucleotide DNA strands held together? (3 marks)

The two antiparallel strands of DNA are held together by hydrogen bonds joining the bases of each complementary nucleotide; Adenine is held to Thymine by 2 hydrogen bonds, and Guanine to Cytosine by 3 hydrogen bonds.

Answered by Srishti A. • Biology tutor

8865 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Why should different animals have different haemoglobin types

Explain how certain molecules or ions increase the activity of enzymes.

Explain synaptic transmission at a cholinergic synapse.

Describe how oxygen in the air reaches capillaries surrounding alveoli in the lungs?

Popular Requests

Maths tutor Chemistry tutor Physics tutor Biology tutor English tutor GCSE tutors A level tutors IB tutors Physics & Maths tutors Chemistry & Maths tutors GCSE Maths tutors

CLICK CEOP

Internet Safety

Payment Security

Cyber

Essentials

MyTutor is part of the IXL family of brands:

IXL

Comprehensive K-12 personalized learning

Rosetta Stone

Immersive learning for 25 languages

Wyzant

Trusted tutors for 300 subjects

Education.com

35,000 worksheets, games, and lesson plans

Vocabulary.com

Adaptive learning for English vocabulary

Emmersion

Fast and accurate language certification

Thesaurus.com

Essential reference for synonyms and antonyms

Dictionary.com

Comprehensive resource for word definitions and usage

SpanishDictionary.com

Spanish-English dictionary, translator, and learning resources

FrenchDictionary.com

French-English dictionary, translator, and learning

Ingles.com

Diccionario ingles-espanol, traductor y sitio de apremdizaje

ABCya

Fun educational games for kids