Bio Test 2 PDF

Here are the definitions for the key terms and concepts related to genetics and heredity from Chapter 4: - **Heredity**: The passing on of physical or mental characteristics genetically from one generation to another. - **Genetics**: The study of genes, genetic variation, and heredity in living org...

Here are the definitions for the key terms and concepts related to genetics and heredity from Chapter 4: - **Heredity**: The passing on of physical or mental characteristics genetically from one generation to another. - **Genetics**: The study of genes, genetic variation, and heredity in living organisms. - **DNA**: Deoxyribonucleic acid, a molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms. - **Gene**: A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring. - **Locus**: The specific physical location of a gene or DNA sequence on a chromosome. - **Polyploid**: Having more than two paired (homologous) sets of chromosomes. - **Asexual reproduction**: Reproduction that involves only one parent and produces offspring that are genetically identical to the parent. - **Sexual reproduction**: Reproduction that involves two parents and the fusion of gametes to produce genetically diverse offspring. - **Mitosis**: The process of cell division in which a single cell divides into two identical daughter cells. - **Interphase**: The phase of the cell cycle where the cell grows, replicates its DNA, and prepares for cell division. - **Chromatin**: The material of which the chromosomes of organisms other than bacteria (e.g., eukaryotes) are composed. - **Sister chromatid**: Two identical copies of a single replicated chromosome. - **Cytokinesis**: The division of the cytoplasm following mitosis or meiosis. - **Cloning and Dolly the sheep**: The process of producing genetically identical copies of a cell or organism. Dolly the sheep was the first mammal cloned from an adult somatic cell. - **Biotechnology**: The use of living systems and organisms to develop or make products. - **Genetically Modified organism (GMO)**: An organism whose genetic material has been altered using genetic engineering techniques. - **Gamete**: A mature sexual reproductive cell, such as a sperm or egg, that unites with another cell to form a new organism. - **Fertilization**: The fusion of gametes to initiate the development of a new individual organism. - **Zygote**: The initial cell formed when two gamete cells are joined by means of sexual reproduction. - **Ova**: The female reproductive cell or gamete. - **Meiosis**: A type of cell division that results in four daughter cells, each with half the number of chromosomes of the parent cell. - **Homologous chromosomes**: Chromosome pairs that have the same genes at the same loci but possibly different alleles. - **Tetrad**: A group of four chromatids formed during meiosis. - **Synapsis**: The pairing of homologous chromosomes during meiosis. - **Crossing over**: The exchange of genetic material between homologous chromosomes during meiosis. - **Gametogenesis**: The process by which gametes are produced through meiosis. - **Spermatogenesis**: The process of sperm cell development. - **Oogenesis**: The process of egg cell development. - **Karyotype**: The number and visual appearance of the chromosomes in the cell nuclei of an organism. - **Sex chromosomes**: Chromosomes that determine an individual's sex. - **Autosomes**: Any chromosome that is not a sex chromosome. - **Nondisjunction**: The failure of homologous chromosomes or sister chromatids to separate properly during cell division. - **Trisomy**: The presence of an extra chromosome in a cell. - **Monosomy**: The presence of only one copy of a particular chromosome in a cell. - **Down syndrome**: A genetic disorder caused by the presence of all or part of a third copy of chromosome 21. - **Prenatal testing**: Testing done during pregnancy to detect genetic disorders or birth defects. - **Maternal inheritance**: The inheritance of genetic traits through the mother. - **Paternal inheritance**: The inheritance of genetic traits through the father. - **Klinefelter syndrome**: A genetic condition in which a male is born with an extra copy of the X chromosome. - **Turner syndrome**: A genetic condition in which a female is born with only one X chromosome. - **Patau syndrome**: A genetic disorder caused by the presence of an extra copy of chromosome 13. - **Edwards syndrome**: A genetic disorder caused by the presence of an extra copy of chromosome 18. Here are the definitions for the key terms and concepts from Chapters 5 and 6: ### Chapter 5: - **Trait**: A characteristic or feature of an organism. - **True-breeding organism**: An organism that always passes down certain phenotypic traits to its offspring. - **Hybrid**: Offspring resulting from the cross between two different true-breeding parents. - **Cross**: The mating of two individuals to produce offspring. - **P generation**: The parental generation in a breeding experiment. - **F1 generation**: The first filial generation, offspring of the P generation. - **Monohybrid cross**: A genetic cross involving one trait. - **F2 generation**: The second filial generation, offspring of the F1 generation. - **Law of segregation**: Mendel's law stating that alleles segregate independently during the formation of gametes. - **Allele**: Different forms of a gene. - **Homozygous**: Having two identical alleles for a particular gene. - **Heterozygous**: Having two different alleles for a particular gene. - **Genotype**: The genetic makeup of an organism. - **Phenotype**: The physical appearance or traits of an organism. - **Dominant allele**: An allele that is expressed in the phenotype when present. - **Recessive allele**: An allele that is only expressed in the phenotype when two copies are present. - **Punnett square**: A diagram used to predict the outcome of a genetic cross. - **Probability**: The likelihood of a particular event occurring. - **Test cross**: A cross between an individual with a dominant phenotype and a homozygous recessive individual. - **Complete dominance**: A form of dominance in which the dominant allele completely masks the recessive allele. - **Incomplete dominance**: A form of dominance in which the heterozygous phenotype is a blend of the two homozygous phenotypes. - **Codominance**: A form of dominance in which both alleles contribute to the phenotype. - **Pedigree**: A diagram that shows the occurrence and appearance of phenotypes in a family across generations. - **Autosomal inheritance**: Inheritance of genes located on autosomes (non-sex chromosomes). - **Sex-linked**: Genes located on the sex chromosomes. - **X-linked**: Genes located on the X chromosome. - **Mutation**: A change in the DNA sequence. - **Carrier testing**: Testing to determine if an individual carries a genetic mutation. - **Genetic screening**: Testing to identify individuals at risk for genetic disorders. - **Dihybrid cross**: A genetic cross involving two traits. - **Law of independent assortment**: Mendel's law stating that alleles of different genes segregate independently during gamete formation. - **Product law**: The probability of two independent events occurring together. ### Chapter 6: - **Nucleotide**: The building block of DNA and RNA, consisting of a sugar, phosphate group, and nitrogenous base. - **Complementary base pairing**: The specific pairing of adenine with thymine and guanine with cytosine in DNA. - **Point mutation**: A mutation that affects a single nucleotide. - **Chromosome mutation**: A mutation that involves changes in the structure of a chromosome. - **Spontaneous mutation**: A mutation that occurs naturally without external influence. - **Induced mutation**: A mutation that is caused by external factors such as radiation or chemicals. - **Antibiotic resistant**: Ability of bacteria to survive exposure to antibiotics. - **Transposon**: A DNA sequence that can change its position within the genome. - **Transposition**: The movement of a transposon to a new location in the genome. - **Human Genome Project (HGP)**: An international research project that mapped and sequenced the entire human genome. - **Human genome**: The complete set of genetic information in humans. - **Coding DNA**: DNA that contains instructions for making proteins. - **Non-coding DNA**: DNA that does not code for proteins. - **DNA fingerprinting**: A technique used to identify individuals based on their unique DNA profiles. - **Restriction enzyme**: Enzyme that cuts DNA at specific sequences. - **Recombinant DNA**: DNA that has been artificially combined from multiple sources. - **Gene therapy**: The introduction of genes into an individual's cells to treat or prevent disease. - **Target cell**: The specific cell type that a treatment or therapy is intended to affect. - **Vector**: A vehicle used to transfer genetic material into a cell. ### Genetics Unit Review Practice Difference between spermatogenesis and oogenesis Difference between trisomy and monosomy Difference between asexual and sexual Restriction enzyme - cut Incomplete dominance shows both 1. **Why did Gregor Mendel use the garden pea plant to study genetics?** - Gregor Mendel used the garden pea plant because it had easily observable traits, a short generation time, and the ability to self-fertilize or cross-fertilize. 2. **What is a recessive allele?** - A recessive allele is an allele that is only expressed in the phenotype when two copies are present (homozygous recessive). 3. **Genotype and phenotype ratios for the hairline in the children of a mother with a widow's peak (heterozygous) and a husband with a widow's peak (heterozygous).** - Genotype ratio: 1 homozygous dominant : 2 heterozygous : 1 homozygous recessive - Phenotype ratio: 3 with widow's peak : 1 without widow's peak 4. **Phenotypic ratios of the offspring from crossing a purple flowered pea plant with round seeds (heterozygous) and a white flowered wrinkle-seeded plant.** - Phenotypic ratio: 4 purple flowered round seeds : 4 purple flowered wrinkled seeds : 4 white flowered round seeds : 4 white flowered wrinkled seeds 5. **Phenotype ratios in the children of two double heterozygote parents with hitchhiker's thumbs and PTC tasting ability.** - Phenotype ratio: 9 hitchhiker's thumbs and can taste PTC : 3 hitchhiker's thumbs and cannot taste PTC : 3 straight thumbs and can taste PTC : 1 straight thumbs and cannot taste PTC 6. **Phenotype and genotype ratios from crossing two pink snapdragon plants.** - Phenotype ratio: 1 red : 2 pink : 1 white - Genotype ratio: 1 RR : 2 Rr : 1 rr 7. **Possibility of blood type O child from parents with blood type A and B.**  - Yes, it is possible for them to have a child with blood type O. - Punnett square: | |A|O| |---|---|---| | B | AO | BO | | B | AO | BO | 8. **Possible blood types in children of parents with blood type AB.** - Possible blood types in children: A, B, AB, O 9. **Determination of Debbie's blood type and genotype from her parents' blood types and children's blood types.** - Debbie's blood type: AB - Debbie's genotype: IAIB 10. **Draw and label the cell cycle.** -  11. **Overall purpose of mitotic cell division.** - The overall purpose of mitotic cell division is to produce two genetically identical daughter cells for growth, repair, and asexual reproduction. 12. **Diagram of a chromosome with labels.** -  13. **Meaning of "diploid" and diploid number for human cells.** - Diploid: Having two sets of chromosomes. - Diploid number for human cells: 46 chromosomes. 14. **Inheritance of red-green colorblindness in a boy and potential inheritance by his children.** - The boy inherited the defective allele from his mother. - If he marries a normal vision girl: - Punnett square: | | X^N | X^N | |---|-----|-----| | X^N | X^N X^N | X^N X^N | | X^r | X^N X^r | X^N X^r | - None of their sons will be colorblind, but all daughters will be carriers. 15. **Events during prophase, metaphase, anaphase, and telophase of mitosis.** - Prophase: Chromosomes condense, nuclear envelope breaks down. - Metaphase: Chromosomes align at the metaphase plate. - Anaphase: Sister chromatids separate and move to opposite poles. - Telophase: Chromosomes decondense, nuclear envelope reforms. 16. **Difference in cytokinesis between plant and animal cells.** - In plant cells, cytokinesis involves the formation of a cell plate, while in animal cells, it involves the formation of a cleavage furrow. 17. **Overall purpose of meiosis.** - The overall purpose of meiosis is to produce gametes with half the number of chromosomes for sexual reproduction. 18. **Number of cells potentially produced in meiotic cell division from one diploid cell.** - Meiotic cell division produces four haploid cells from one diploid cell. ### Genetics Questions Continued: 19. **Meiosis:** a. **When does it occur?** - Meiosis occurs during the formation of gametes (sperm and egg cells) in sexually reproducing organisms. b. **What kind of chromosomes are involved?** - Homologous chromosomes (one from each parent) are involved in meiosis. c. **End result and significance to the overall purpose of meiosis:** - The end result is the production of four haploid cells with genetic variation. This is significant for sexual reproduction as it ensures genetic diversity in offspring. 20. **Another important event in meiosis:** - **Independent assortment:** During meiosis, homologous chromosomes randomly align and separate into daughter cells, leading to genetic variation in the offspring. 21. **Nondisjunction and its role in Down syndrome:** - **Nondisjunction:** Failure of chromosomes to separate properly during cell division. - **Role in Down syndrome:** Nondisjunction of chromosome 21 can result in an individual having an extra copy of chromosome 21, leading to Down syndrome. 22. **Karyotype:** - A karyotype is a visual display of an individual's chromosomes arranged by size, shape, and banding pattern. It can reveal chromosomal abnormalities and genetic disorders. 23. **Pedigree:** - A pedigree is a diagram that shows the occurrence and inheritance of a particular trait or disease within a family across multiple generations. 24. **Discovery of the chemical structure of DNA:** - The chemical structure of DNA was discovered by James Watson and Francis Crick in 1953. - The structure is known as the double helix. 25. **Four nitrogenous bases in DNA:** - Adenine (A), Thymine (T), Guanine (G), Cytosine (C). 26. **Complementary base pairing:** - Complementary base pairing is the specific pairing of nitrogenous bases in DNA where adenine pairs with thymine and guanine pairs with cytosine. 27. **Components of a nucleotide:** - A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base. 28. **Changes in chromosome structure:** - Deletion: Loss of a chromosome segment. - Duplication: Repeat of a chromosome segment. - Inversion: Reversal of a chromosome segment. - Translocation: Movement of a chromosome segment to a non-homologous chromosome. 29. **DNA fingerprinting process:** - DNA fingerprinting involves extracting DNA, amplifying specific regions using PCR, digesting the DNA with restriction enzymes, separating fragments by gel electrophoresis, and analyzing the unique banding patterns. 30. **Spontaneous vs. induced mutations:** - **Spontaneous mutations:** Naturally occurring mutations due to errors in DNA replication or environmental factors. - **Induced mutations:** Mutations caused by external factors like radiation or chemicals. 31. **Plasmids and restriction enzymes in genetic engineering:** - Plasmids are small, circular DNA molecules used as vectors to transfer genes into host cells. - Restriction enzymes cut DNA at specific sequences, allowing for the insertion of desired genes into plasmids for genetic engineering purposes.