Biology Chapter on Genetics and Species Concept

Thread-like structures in cells containing genes and DNA.

Identifying chromosomes based on appearance & size (often through staining).

Two identical strands of a chromosome held together, before separation.

Complete set of chromosomes in an organism.

Point where two chromatids are joined.

Organisms that can interbreed and produce fertile offspring are the same species.

A group of the same species living in the same area at the same time.

Two populations of a species stop interbreeding, and eventually become different species over time.

Fundamental characteristic that distinguishes a species, all members have the same number.

Chromosome changes (mutations) are rare in species, though important.

A visual display of an organism's chromosomes arranged by homologous pairs, showing length and position of the centromere.

A chromosome that is not a sex chromosome.

A chromosome that determines biological sex, either XX for female or XY for male.

All the DNA in an organism.

Different forms of a gene

Positions in a gene where multiple DNA bases can be present.

A DNA sequence change at a single nucleotide affecting the SNP.

Eukaryotic genomes are larger than prokaryotic genomes, with many non-functional regions.

Non-coding DNA sections in a genome, with no known function.

Different species have different genome sizes, even similar ones.

Differences in the order of nucleotides within genes, caused by mutations, recombination, or variations between species.

Genome size is measured in picograms (pg) for mass and megabase pairs (Mbp) for the number of base pairs.

Even though there are many differences between species, the base sequence often shows only small or no differences.

Determining the complete order of nucleotides in an organism's genome.

A tool used to identify species based on a series of paired choices, usually based on physical characteristics.