Bio 30 - Unit 3

Genetics

The study of patterns of inheritance, genes, and genetic variation

Genes

Units of instruction located on chromosomes that produce or influence a specific trait

Alleles

Two or more alternate forms of a gene

Mitosis

Nuclear division that maintains the number of chromosomes

Meiosis

Cell division that reduces the number of chromosomes

Meiosis 1

separates the matching pairs of chromosomes

Chromosomes

DNA tightly packed into a condensed strand

Chromatid

One of the two identical halves of a replicated chromosome

Centromere

Constricted region of a chromosome holding sister chromatids together

Somatic cells

Body cells specialized to perform specific functions

Homologous chromosomes

Chromosomes of similar length and banding patterns

Ploidy

Number of chromosome sets in a nucleus

Growth 1

Phase involving the growth of organelles

Synthesis

Phase involving DNA replication

Interphase

Time between divisions where the cell prepares for division

Prophase

Phase where nuclear membrane disappears, chromosomes condense

Telomere

Structures at the end of chromosomes made from DNA sequences and proteins

Crossing over

Exchange of segments between non-sister chromatids

Karyotype

Set of chromosomes of an individual

Binary fission

Splitting of one cell into two cells

Gregor Mendel

Father of genetics, studied inheritance in pea plants

Law of dominance

Dominant allele masks the expression of the recessive form

Phenotype

Observable traits determined by an organism's genes

DNA

Polymer composed of nucleotides that carry genetic information

Purines

Double ring nitrogen bases - adenine and guanine

Transcription

Process of making mRNA from DNA

RNA

Single-stranded genes that exist throughout the cell