Genetic Engineering and Bacterial Transfer Quiz

Meiosis

• Cell division in reproductive cells
• Produces gametes (egg or sperm) that are haploid
• Referred to as reduction division

Variation

• Achieved by independent assortment and crossing over
• Crossing over occurs in prophase I
  • Homologous chromosomes pair up (synapsis)
  • Non-sister chromatids exchange genetic material
  • creating new combinations of alleles not found in the parent cell
• Independent assortment happens in metaphase I and anaphase I
  • Random arrangement of homologous chromosome pairs along the metaphase plate
  • Results in different combinations of chromosomes in daughter cells
  • Increases genetic variation

Purpose of Meiosis

• Reduce chromosome number by half
• Create genetically diverse gametes
• Contributes to genetic variation

Spermatogenesis

• Production of mature sperm cells
• Takes place in the testes
• Produces 4 sperm cells
• Cytoplasm is divided equally

Oogenesis

• Production of mature egg cells
• Takes place in the ovaries
• Produces only 1 ovum
• Cytoplasm is divided unequally

Nondisjunction

• Failure of chromosomes to separate properly during meiosis
• Aneuploidy can result
  • Daughter cell with one less chromosome (monosomy)
  • Daughter cell with one extra chromosome (trisomy)
• Resulting issues
  • Down syndrome
  • Turner syndrome
  • Triple-X syndrome

Mendelian Genetics

• Heterozygous: Individual with two different alleles for a characteristic
• Homozygous: Individual with two of the same alleles for a characteristic
• Dominant: Allele that is always expressed when present
• Recessive: Allele that is expressed only when the dominant allele is absent
• Genotype: Genetic makeup of an individual
• Phenotype: Observable characteristics of an individual

Monohybrid Cross

• Cross between two parents resulting in hybrid offspring, following one trait and one set of alleles.
• Example: Let E represent cyclops, e represent compound eyes

Test Cross

• Used to determine the genotype of an organism showing a dominant phenotype whose genotype is unknown.
• Cross the organism with a homozygous recessive individual
• This reveals the recessive alleles present

Dihybrid Cross

• Cross between two parents following two traits, two sets of alleles.
• Calculating probabilities of genotypes and phenotypes in the offspring.
• Example: Crossing heterozygous individuals for both traits (AaBb × AaBb)

Beyond Mendel

• Incomplete dominance: Hybrid offspring shows a blending of two traits
• Codominance: Both traits of the parents are fully expressed in the offspring

Sex Linkage

• Traits passed onto offspring via X or Y chromosomes.
• Diseases have a higher chance of occurring in males.
• Females have back-up X chromosomes

Karyotype

• Chromosomes of an individual sorted by size and type
• Prenatal testing can identify chromosomal abnormalities
  • Methods include chorionic villus sampling (CVS) and amniocentesis

Chromosomal Abnormalities

• Trisomy: Three copies of a homologous chromosome
• Monosomy: Single copy of a homologous chromosome

Pedigrees

• Diagrams of individuals' ancestors in human genetics.
• Mendelian traits
• Determine genotypes and phenotypes for traits in a family.
• Helps trace the inheritance of desired and undesirable traits.

Unit 2: Evolution

• Darwin's Theory of Evolution:
  • Organisms produce more offspring than can survive
  • Individuals vary
  • Best-adapted individuals survive and reproduce
• Survival of the fittest: Slight variations within individuals can be beneficial for survival.
• Lamarck's Theory: Organs and parts develop with use, and these changes are passed to offspring.
• Homologous structures: Similar structures, common ancestry
• Analogous structures: Similar structures, no common ancestry
• Hardy–Weinberg principle: A population will remain stable through time. This occurs when the population is large, random mating exists, there is no migration or mutation, no natural selection is taking place
• Evidence of evolution:
  • Fossil record
  • Embryology
  • Biochemistry (DNA)

Population Shifts in Evolution

• Stabilizing selection: Favors average traits
• Directional selection: Favors individuals with extreme traits
• Disruptive selection: Favors individuals with extreme traits, leading to distinct population groups

Nonrandom Mating

• Organisms mate based on geographic proximity or chosen mate.
• This can amplify some traits and decrease others

Genetic Drift

• Changes in allele frequencies due to chance events.
• Bottleneck effect: Sudden reduction in population size due to a natural disaster.
• Founder effect: A few individuals establish a new isolated population, leading to a different gene pool from the original.

Isolating Mechanisms

• Any barrier that prevents successful breeding between populations.
• Geographical isolation: Populations physically separated.
• Reproductive isolation: Barriers that prevent interbreeding, like different mating times, behaviours, gametic differences etc.
• Allopatric speciation: Formation of new species when populations are physically separated.
• Sympatric speciation: Formation of new species without geographical separation.

Prezygotic and Postzygotic Barriers

• Prezygotic barriers: Barriers that prevent fertilization
  • Temporal, mechanical, behavioural, gametic isolation
• Postzygotic barriers: Barriers that occur after fertilization
  • Zygote mortality, hybrid inviability, hybrid infertility

Unit 3: Animal Systems Physiology

• Respiratory system:
  • Alveoli, pleural membrane, external and internal intercostal muscles
  • Respiration: Gas exchange, ventilation, Tidal Volume(TV), breathing, etc.
• Circulatory System:
  • Heart's four chambers (right and left atrium → right and left ventricle), blood vessels (arteries, veins, capillaries)
  • Heart's valves, pumping action, blood flow.

Types of blood

• Plasma, red blood cells, white blood cells
• Blood types
• Diseases pertaining to blood

Unit 4: Diversity of Living Things

• Taxonomy: Classification of organisms (e.g., domain, kingdom, phylum, class, order, family, genus, species)
• Six kingdoms: Bacteria, archaea, protists, fungi, plants, animals
• Characteristics of each kingdom: Based on characteristics like cell type, nutrition, etc.

Viruses (General)

• Structure: Nuclei acid, Capsid, Envelope
• Function: Genetic info, protection, etc.
• Lytic cycle, lysogenic cycle

Genetic Engineering

• Using certain viruses (or manipulating them) to insert genes into cells for treatment or other purposes
• Method of manipulating DNA for treatment, research and other practical applications

Bacteria

• Morphology (shapes: coccus, bacillus, spirillum)
• Reproduction: binary fission
• Structual differences (cell wall composition, capsules, flagella, plasmids)
• Different types of reproduction (conjugation, transformation, transduction).