Molecular Genetics and Heredity Study Guide Answers DNA

Molecular Genetics and Heredity Study Guide Answers

DNA a. monomer- nucleotide b. Base pairing- A—T and C—G c. Two strands are said to be complementary to each other. d. DNA polymerase- catalyzes the addition of nucleotides to form a complementary DNA strand e. Watson and Crick- credited with the discovery of the structure of DNA RNA a. Base pairing- A—U and C—G b. r. RNA- makes up the ribosomal subunit c. m. RNA- carries the DNA code from nucleus to ribosomes d. t. RNA- transfers the correct amino acid

• Transcription- RNA is produced from the DNA template • Translation- RNA protein • Codon- a nucleotide triplet • Sex chromosomes- X and Y (include genes that determine an individual’s sex • Locus- a genes location along a chromosome • Sexual life cycles- all go through meiosis, fertilization, and produce gametes • Zygote- the result of fertilization of egg and sperm • Prophase I- crossing over occurs

• Meiosis a. steps: 1) chromosomes move to middle of cell in pairs 2) Alignment of tetrads (pairs) at metaphase plate 3) Separation of homologues 4) Separation of sister chromatids 5) Formation of 4 new daughter cells • Gregor Mendel a. Conclusion from research- traits are inherited in discrete units, and are not the results of “blending” • True breeding- homozygous for a trait (AA or aa) • Homozygous- having two of the same alleles (AA or aa) • Heterozygous- having two different alleles (Aa)

• ABO blood groups- has multiple alleles (A, B, and O) a. example- AO= Type A; OO= Type O, etc. • Polygenic inheritance- a trait controlled by more than one gene a. example- skin pigmentation in humans • Gene linkage- genes located together on the same chromosome and are inherited together • 2 n=16 a. What does that mean- each cell has 8 homologous pairs • DNA ligase- connects segments of DNA • DNA replication- DNA bases unzip at the hydrogen bonds and new complementary bases pair up with original template • Crossing over- homologous chromosomes cross over and exchange genetic information

• Gene- a heritable unit that determines a character and can exist in different forms • Allele- an alternative version of a gene • Character- a heritable feature that varies among individuals • Trait- a variant for a character • Dominant allele- determines phenotype in a heterozygous (Aa) • Recessive allele- has no effect on phenotype in a heterozygote • Genotype- genetic makeup of an individual • Phenotype- an organism’s appearance or observable traits • Testcross- a cross between an individual with unknown genotype and homozygous recessive individual • Monohybrid cross- a cross involving only one trait