DNA and Genetics Quiz

DNA and Genetics

DNA and Genes

• Deoxyribonucleic acid (DNA) is the full name of DNA
• DNA's function is to store genetic information
• DNA's structure is a double helix, twisted ladder shape with rungs (base pairs) and uprights (sugar-phosphate backbone)
• DNA is located in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells
• Complementary base pairing is the process where adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C)
• Genes are the units of heredity that carry information from one generation to the next
• DNA, chromosomes, and genes are related: genes are sections of DNA that code for proteins, and multiple genes are found on a chromosome

Mitosis

• Mitosis is the process of cell division that results in two identical daughter cells
• DNA must be replicated before cell division to ensure each new cell receives a complete copy of DNA
• Single-stranded DNA is a single chain of nucleotides, while double-stranded DNA is two complementary strands
• The stages of mitosis are: interphase, prophase, metaphase, anaphase, and telophase
• The outcome of mitosis is two identical daughter cells with the same number of chromosomes as the parent cell

Meiosis

• Meiosis is the process of cell division that results in four unique daughter cells (gametes) with half the number of chromosomes as the parent cell
• Homologous chromosomes are pairs of chromosomes that carry the same genes in the same order
• Human cells have 46 chromosomes, and human sex cells (gametes) have 23 chromosomes
• The stages of meiosis are: interphase, prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II, and telophase II
• The outcome of meiosis is four unique daughter cells with half the number of chromosomes as the parent cell
• Meiosis is important for genetic variation and increasing genetic diversity

Simple Inheritance

• Dominant traits are expressed when one copy of the allele is present, while recessive traits are expressed when two copies of the allele are present
• Alleles are different forms of a gene, and genotypes are the genetic makeup of an individual
• Heterozygous individuals have two different alleles, while homozygous individuals have two copies of the same allele
• Phenotypes are the physical expressions of genotypes
• Dominant alleles are represented by a capital letter, while recessive alleles are represented by a lowercase letter

Punnett Squares

• Punnett squares are used to predict the possible genotypes and phenotypes of offspring from a genetic cross
• The probability of each genotype and phenotype can be calculated using Punnett squares
• Carriers are heterozygous individuals who carry a recessive allele but do not express the recessive trait

Sex-Linked Inheritance

• Autosomes are non-sex chromosomes, while sex chromosomes are X and Y chromosomes
• Sex-linked inheritance occurs when a gene is located on a sex chromosome
• Sex-linked genes have different alleles represented by superscripts (e.g., X^R and X^r)
• Punnett squares can be used to predict the genotype and phenotype of offspring in sex-linked inheritance
• Female parents' genotypes affect the genotype and phenotype of male offspring in sex-linked inheritance

Pedigrees

• Pedigrees are family trees that show the inheritance of autosomal and sex-linked traits
• By analyzing pedigrees, the genotype and phenotype of individuals can be predicted