Genetics Key Terms and Concepts

Flashcards on genetics terminology, chromosome structure, and allele concepts.

What is DNA?

The molecule that carries genetic information for development and functioning of organisms.

What is a chromosome?

A subunit of the genome in the nucleus of a cell, consisting of a DNA molecule and associated proteins.

What are nucleotides?

Small molecules that make up the sequence of a DNA molecule (adenine, cytosine, guanine, and thymine).

What are duplicated chromosomes?

Two connected subunits of DNA that are duplicates of each other, often appearing as an 'X' shape.

What does diploid mean?

An organism with two versions (a pair) of each chromosome.

What are chromosome pairs?

Unconnected subunits of DNA that contain the same genes but are not copies of each other; one inherited from each parent.

What is a gene?

A segment of DNA on a chromosome that provides information for making molecules like mRNA and proteins.

What is an allele?

A version of a gene that differs from other versions based on nucleotide sequence.

What does homozygous mean?

A diploid individual with the same allele in both versions of a gene.

What does heterozygous mean?

A diploid individual with different alleles of a given gene.

What are chromosome copies?

Connected subunits of DNA that are duplicates of each other with the same genes and information.

How do chromosomes occur in diploids?

Occur in pairs, with one member of each pair inherited from the mother and the other from the father.

In a given person's body, where do chromosomes come from?

One member of each chromosome pair is inherited from one's mother in her egg cell.

What is a genotype?

The set of genes present in an organism or cell.

What is a phenotype?

The observable characteristics of an organism resulting from the interaction of its genotype with the environment.

What is heredity?

The process by which genetic information is passed from parents to offspring.

What is genetics?

The study of heredity and variation of inherited characteristics.

What is a Punnett square?

A diagram that predicts the possible genotypes and phenotypes of offspring from a cross between two parents.

What is a monohybrid cross?

A cross in which only one characteristic is tracked.

What is a dihybrid cross?

A cross in which two characteristics are tracked simultaneously.

What is genetic composition?

The genetic makeup of an organism with respect to a particular trait.

What is co-dominance?

The condition where both alleles in a heterozygous individual are expressed.

What is incomplete dominance?

The condition where neither allele is fully dominant, and the heterozygous phenotype is intermediate between the two homozygous phenotypes.