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Chapter 6
Meiosis and Mandel
Question | Answer |
---|---|
somatic cell | body cells that make up most tissues and organs |
gamete | sex cells |
homologous chromosome | two chromosomes that have the same length/ general appearance |
autosome | chromosomes that contain genes for characteristics not directly related to the sex of an organism |
sex chromosome | directly control development of sexual characteristics |
sexual reproduction | involves fusion of two gametes |
fertilization | actual fusion of egg and sperm cell |
diploid | cell has two copies of each chromosome |
haploid | cell has only one copy of each chromosome |
meiosis | form of nuclear division that divides a diploid cell into haploid cells |
gametogenesis | production of gametes |
sperm | male gamete |
egg | female gamete |
polar body | cells with little more than DNA that are eventually broken down |
trait | distinguishing characteristics that are inherited |
genetics | study of biological inheritance patterns and variation in organisms |
purebred | line of a self-pollinated organism |
cross | the mating of two organisms |
law of segregation | Mendel's two key conclusions |
gene | piece of DNA that provides 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 | two of the same alleles at a specific locus |
heterozygous | two different alleles at a specific locus |
genome | organism's genetic material |
genotype | genetic makeup of a specific set of genes |
phenotype | physical characteristics of an individual organism |
dominant | allele that is expressed when two different alleles/ two dominant alleles are present |
recessive | allele that is expressed only when two copies are present |
Punnett square | grid system for predicting all possible genotypes resulting from a cross |
monohybrid cross | cross that examines the inheritance of only one specific trait |
testcross | cross between an organism with an unknown genotype and an organism with the recessive phenotype |
dihybrid cross | crosses that examine the inheritance of two different traits |
law of independent assortment | states that allele pairs separate independently from each other during meiosis |
probability | likelihood that a particular event will occur |
crossing over | exchange of chromosome segments between homologous chromosomes during prophase I of meiosis I |
genetic linkage | genes located closer together tend to be inherited together |