Life Sciences 11 - unit 1

Flashcards about DNA and its role in genetics and evolution.

What is DNA?

Deoxyribonucleic acid, a long double strand of nucleotides.

Nitrogenous base, ribose sugar, and phosphate.

What are the three components of a nucleotide?

What are the four nitrogenous bases in DNA?

Cytosine, Thymine, Guanine, Adenine.

Which nitrogenous bases are purines?

Adenine and Guanine.

Which nitrogenous bases are pyrimidines?

Thymine and Cytosine.

What is the difference in the ring structures of purines and pyrimidines?

Purines have 2 ring structures, pyrimidines have 1.

How do two single strands of DNA associate with one another?

Hydrogen bonds between nitrogenous bases.

What is a gene?

Segments of DNA that code for proteins, antibodies, or structural molecules.

What cellular structure makes proteins, antibodies, and structural molecules?

The ribosome.

What is a genome?

The entire genetic makeup of an organism.

What does the genotype of an organism refer to?

One specific trait.

What is the phenotype?

The observable physical appearance of how genes manifest.

What are alleles?

Possible variations of a particular gene (e.g., brown, green, or blue eyes).

What factors can cause DNA mutations?

DNA replication errors, radiation, chemical exposure.

How can mutations be characterized?

Adaptive or maladaptive.

What is a gene pool?

All the genes/alleles present within a mating population.

What factors can affect the gene pool?

Death, physical separation, isolation, mutations, births.