DNA and Heredity Grade 10 Exam Revision

A collection of key vocabulary terms and definitions related to DNA and heredity for Grade 10 students.

Genome

The entire DNA of an organism.

Nucleotide

The basic building block of DNA, consisting of a nitrogenous base, a pentose sugar, and a phosphate group.

Chromosome

A structure in the nucleus made of DNA and proteins that contains genes.

Allele

Variations of the same gene that can give rise to different inherited characteristics.

Phenotype

The observable characteristics of an organism.

Genotype

The combination of alleles that determines a specific trait.

Homozygous

Having two identical alleles for a particular gene.

Heterozygous

Having two different alleles for a particular gene.

Polygenic inheritance

A trait controlled by more than one gene.

Codominance

A situation where both alleles in a heterozygous individual contribute to the phenotype.

Punnett square

A diagram used to predict the outcome of genetic crosses.

DNA polymerase

An enzyme that synthesizes a new DNA strand during replication.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing a protein from mRNA at the ribosome.

Mutation

A rare change in the DNA sequence that can be inherited and may affect phenotype.

Insertion mutation

A mutation in which a new base is added into the DNA sequence.

Deletion mutation

A mutation in which a base is removed from the DNA sequence.

Substitution mutation

A mutation in which one base is replaced by another in the DNA sequence.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during replication.

Blood group alleles

Different versions of the gene that determines blood type: A, B, and O.