Chapter 6 Vocab Flashcards
Gametes
Are sex cells - ova, or eggs, in the female, and spermatozoa, or sperm cell in the male
Somatic
Also called body cells make up most of your body tissues and organs except gametes
Homologous Chromosomes
Are two chromosomes
- one inherited from the mother, one from the father
- that have the same length and general appearance
Autosomes
Chromosomes that contains genes for characteristics not directly related to the sex of an organism
Sex Chromosomes
Directly control the development of sexual characteristics
Sexual Reproduction
Involves the fusion of two gametes that result in offspring that are genetic mixture of both parents
Fertilization
The fusion of an egg and a sperm cell
Diploid
Cells have two copies of each chromosomes:
One copy from the mother and one from the father
Haploid
Cells have only one copy of each chromosome
Meiosis
A form of nuclear division that divides a diploid cell into haploid cells
Gametogenesis
The production of gametes
Sperm
The male gamete
Egg
Smaller than the sperm, female gamete
Polar bodies
Cells with little more than DNA that are eventually broken down
Traits
Are distinguishing characteristics that are inherited
Genetics
The study of biological inheritance patterns and variation in organisms
Purebred
Type of organism whose ancestors are genetically uniform
Cross
The mating of two organisms
Law of segregation
Mendels first law, stating that
- Organisms inherit two copies of genes, one from each parent, and
- Organism donate only one copy of each gene in their gametes because the genes separate during gamete formation
Gene
Piece of DNA that provided a set of instructions to a cell to make a certain protein
Allele
Any of the alternative forms of a gene that may occur at a specific locus
Homozygous
Alleles are identical to each other
Heterozygous
Alleles are different from each other
Genome
All of an organisms genetic material
Genotype
Often focus on a single trait or set of traits, is all of an organisms genes typically refers to the genetic makeup of a specific set of genes
Phenotype
The physical characteristics, or traits, of an individual organism make up
Dominant
Allele is expressed when two different alleles are present
Recessive
Allele is expressed only when two copies are present
Monohybrid crosses
Cross or mate between organisms that involves only one pair of contrasting traits
Testcross
A cross between an organism with an unknown genotype and an organism with recessive phenotype
Dihybrid crosses
Crosses that examine the inheritance of two different traits
Law of independent assortment
States that allele pairs separate independently of each other during gamete formation, or meiosis
Probability
The likelihood that a particular event will happen
Crossing over
The exchange of chromosome segments between homologous chromosomes during prophase 1 op meiosis 1
Genetic Linkage
Genes located close together tend to be inherited together