Biology Chapter on Nucleotides and Nucleic Acids

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Questions and Answers

What is the main distinction between purines and pyrimidines?

Purines have two ring structures, while pyrimidines have one. (correct)

Purines have one ring structure, while pyrimidines have two.

Purines pair exclusively with purines, while pyrimidines pair exclusively with pyrimidines.

Purines are larger than pyrimidines, which are smaller.

According to Chargaff’s Rule, which statement is true?

The total number of cytosine and thymine is equal to the total number of adenine and guanine.

The amount of adenine is equal to the amount of thymine. (correct)

The total number of purines is greater than the number of pyrimidines.

The amount of cytosine is equal to the amount of adenine.

Which component is unique to RNA compared to DNA?

Deoxyribose as a sugar

Double-stranded structure

Thymine as a nitrogenous base

Uracil as a nitrogenous base (correct)

What defines a homozygous recessive genotype?

Two identical recessive alleles. Signup and view all the answers

What is the primary function of RNA in the cell?

Synthesizing proteins using the DNA template. Signup and view all the answers

What is the primary purpose of selective breeding?

To improve specific traits in offspring Signup and view all the answers

Which of the following is a risk associated with selective breeding?

Higher likelihood of genetic disorders Signup and view all the answers

What term describes the offspring that arise from crossing individuals with unlike characteristics?

Hybrid Signup and view all the answers

Who is considered the Father of Genetics?

Gregor Mendel Signup and view all the answers

What does hybrid vigor refer to?

Superior phenotypic traits in hybrid offspring Signup and view all the answers

Which of the following is NOT a step in selective breeding?

Cross-pollinating different species Signup and view all the answers

What is the main economic importance of selective breeding in animals?

To enhance growth and production Signup and view all the answers

What is the initial step in the hybridization process?

Select two genetically distinct parents Signup and view all the answers

Why might royal families select members with similar traits?

To ensure lineage qualities Signup and view all the answers

What is one of Gregor Mendel's laws that relates to genetics?

Law of independent assortment Signup and view all the answers

Study Notes

Nucleotides and Nucleic Acids

Nucleotides are the building blocks of nucleic acids: DNA and RNA.
Composed of a phosphate group, sugar, and nitrogenous base.
DNA contains deoxyribose sugar; RNA contains ribose sugar.

Base Pairing in DNA and RNA

DNA pairs: Cytosine ↔ Guanine, Adenine ↔ Thymine.
RNA pairs: Cytosine ↔ Guanine, Adenine ↔ Uracil.
Purines (2 rings) and pyrimidines (1 ring) must pair consistently to maintain width.

Chargaff’s Rule

Amount of Cytosine equals Guanine and amount of Thymine equals Adenine.
Total purines equal total pyrimidines, maintaining the structure of DNA.

Functions of DNA and RNA

DNA is the blueprint of life, storing genetic information.
RNA synthesizes proteins using DNA as a template, enabling translation.

Genetic Engineering and Classical Breeding

Classical breeding involves mating organisms with desirable traits, either naturally or controlled.
Genetic engineering is the manipulation of an organism's genes, resulting in genetically modified organisms (GMOs).

Genotype and Phenotype

Genotype refers to an organism's complete set of heritable genes, including homozygous dominant (AA), heterozygous (Aa), and homozygous recessive (aa).
Phenotype refers to observable traits influenced by the environment (phenocopy).

Gregor Mendel and Genetic Laws

Considered the father of genetics, famous for his work with pea plants.
Formulated three fundamental laws: dominance and uniformity, segregation, and independent assortment.

Selective Breeding

Involves choosing parent organisms with desirable traits to produce offspring.
Steps include identifying important traits, selecting parents, and continuously breeding the best offspring.

Economic Importance of Selective Breeding

Selective breeding improves traits in animals (e.g., Angus cattle for muscle mass) and plants (e.g., insect-resistant crops).

Benefits and Risks of Selective Breeding

Benefits: Increased food quality and yield; selection of harmless traits (e.g., polled cattle).
Risks: Diseases may spread easily due to decreased genetic variation, and recessive genetic diseases may become more prevalent.

Hybridization

Combines two genetically distinct individuals to create offspring with desirable characteristics.
Often results in hybrid vigor, where offspring exhibit superior traits compared to parents.

Notable Figures

Luther Burbank: Noted American botanist known for creating disease-resistant and high-yield crops, such as Burbank potatoes.

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Description

This quiz covers the fundamentals of nucleotides, the building blocks of nucleic acids like DNA and RNA. You'll learn about their structures, the types of sugars involved, and the base pairing rules essential for DNA and RNA. Test your knowledge on the differences between deoxyribose and ribose, and explore the pairing interactions that maintain the stability of nucleic acids.