Genetics yr 9 Flashcards
Gene
Unit of inherited information in DNA. Can control a characteristic / trait
Chromosomes
Threadlike structures made of dna molecules that contain the genes
What is mitosis
Process by which the nucleus and duplicated chromosomes of a cell divide and are evenly distributed, forming 2 daughter nuclei. Makes identical body cells to allow organisms to grow and repair tissue
What is meiosis
Process by which cells divide twice to produce haploid gametes
What is haploid
Having a single set of chromosomes
What is diploid
Having 2 homologous (matching) sets of chromosomes
Allele
An alternative form of a gene (can br recessive or dominant)
Genotype
The genetic makeup of an organism; an organisms combination of alleles
Phenotype
The observable traits of a organism. How each gene is expressed
Hybrid
Offspring of 2 different trie breeding “BB” and “bb” varieties. Results in heterozygous genotype like “Bb”
Purebred
Identical (dominant or recessive) , true -breeding alleles. “XX” or “xx”
Heterozygous
Having different alleles for a gene (hybrid) . E.g. Bb or Gg
Homozygous
Having identicle alleles for a gene (purebread)
E.g. BB or bb
Recessive
An allele that can be masked by a dominant gene form. Indicated by a lowercase letter
Variation
Difference in individuals of a species caused by both their genes and their environment
