Genetics Exam Review Flashcards

Flashcards from genetics lecture notes using the vocabulary style.

DNA

Carries genetic information, located in the nucleus, double helix shape.

Nitrogen Base (Adenine, Thymine)

A component of DNA; adenine pairs with thymine.

Nitrogen Base (Cytosine, Guanine)

A component of DNA; cytosine pairs with guanine.

RNA

Helps make proteins, single-stranded, located in the nucleus & cytoplasm.

Uracil

A nitrogen base found in RNA that pairs with adenine.

Deletion (in Meiosis)

Part of a chromosome is lost.

Duplication (in Meiosis)

Gene sequence is repeated.

Inversion (in Meiosis)

Gene segment separates & attaches in the wrong place.

Translocation (in Meiosis)

Chromosome changes place with a non-homologous chromosome.

Non-disjunction

Chromosomes/tetrads don't separate properly during Anaphase I or II; leads to addition or deletion of chromosomes in gametes.

Down Syndrome

Trisomy 21, an extra chromosome on the 21st pair.

Patau Syndrome

Trisomy 13, an extra chromosome on the 13th pair.

Edwards Syndrome

Trisomy 18, an extra chromosome on the 18th pair.

Klinefelter's Syndrome

XXY chromosome combination.

Jacobs Syndrome

XYY chromosome combination.

Monosomy

Missing a chromosome.

Phenotype

Physical trait (e.g., brown eyes).

Genotype

Genetic makeup (e.g., Bb, BB).

Dominant

Trait that shows when one allele is present (capital letter).

Recessive

Trait only shows if both alleles are recessive (lowercase).

Allele

Different versions of a gene (e.g., B, b).

Gene

Segment of DNA that codes for a trait.

Heterozygous

Having two different alleles for a trait (e.g., Bb).

Homozygous

Having two identical alleles for a trait (e.g., BB, bb).

Incomplete dominance

Blend of two traits (neither is dominant).

Codominance

Both traits are dominant and expressed (e.g., red and white spots).

Autosomal inheritance

Gene is on chromosome 1-22 (not a sex chromosome).

Autosomal Dominant Inheritance

Only one copy of the dominant allele is needed to show the trait; affected individuals can pass it on.

Autosomal Recessive Inheritance

Two copies of the recessive allele are needed to show the trait; parents can be carriers.

X-linked inheritance

Gene is on the X-chromosome.

Interphase

Replicates DNA, prepares for cell division, and grows.

Prophase (Mitosis)

Chromosomes condense, spindle fibers form, centrioles go to opposite sides.

Metaphase (Mitosis)

Nucleus dissolves, chromosomes line up in the middle.

Anaphase (Mitosis)

Sister chromatids move to opposite sides of the cell.

Telophase (Mitosis)

Nuclear envelope reforms around each set of chromosomes, spindle fibers disassemble.

Prophase I (Meiosis)

Homologous Chromosomes pair up, crossing over occurs.

Metaphase I (Meiosis)

Homologous pairs line up in the middle.

Anaphase I (Meiosis)

Homologous pairs split and go to opposite sides of the cell.

Telophase I (Meiosis)

Cell splits into 2.

Prophase II (Meiosis)

Prepares for another division; looks like 2 cells.

Metaphase II (Meiosis)

Both sets of chromosomes align in the middle.

Anaphase II (Meiosis)

Sister chromatids pull apart to opposite ends of cell.

Telophase II (Meiosis)

Each cell splits into two, giving 4 haploid daughter cells.

Cytokinesis

The division of cytoplasm, making 2 separate daughter cells.

Mitosis

Somatic (body) cells; result 2 identical diploid cells (46 chromosomes).

Meiosis

Gamete (sex) cells; result 4 non-identical haploid cells (23 chromosomes).

Macro Evolution

Big evolutionary changes over time.

Allopatric Speciation

Species get split by a geographical barrier, turning into a different breed.

Sympatric Speciation

Species form in the same area but have different mating preferences (common in plants).

Temporal isolation

Breed at different times.

Behavioral isolation

Different mating behaviors or calls (birds).

Habitat isolation

Live in different habitats.

Gametic isolation

Sperm and egg can't fuse even if mating occurs.

Mechanical isolation

Incompatible reproductive organs.

Archaea/Archaebacteria

Prokaryotic unicellular organisms; asexual reproduction, auto/heterotrophic.

Eubacteria

Prokaryotic unicellular organisms; asexual reproduction, auto/heterotrophic.

Protista

Eukaryotic uni/multicellular organisms; A/sexual reproduction, auto/heterotrophic.

Fungi

Eukaryotic multicellular organisms; sexual reproduction, heterotrophic.

Plantae

Eukaryotic multicellular organisms; sexual reproduction, autotrophic.

Animalia

Eukaryotic multicellular organisms; sexual reproduction, heterotrophic.

Viruses Structure

DNA or RNA inside a protein coat (capsid); may also have lipids and carbohydrates.

Lytic Cycle

Attachment, entry & replication, assembly, release (kills host, symptoms show).

Lysogenic Cycle

Attachment, reproduction, cytokinesis (stays dormant in host, long-term more dangerous).

Fossil Record (Evidence of Evolution)

Shows how organisms changed over time with fossils.

Biogeography (Evidence of Evolution)

Animals gained unique traits to adapt to their environment.

Anatomy (Evidence of Evolution)

Similarities in features of two different animals show they come from a common ancestor.

Homologous Features

Same ancestors

Analogous Features

Different Ancestors

Embryology (Evidence of Evolution)

Babies of different animals look the same (Pig & human fetus).

Biochemical/DNA (Evidence of Evolution)

Similar DNA and proteins are related (Chart).

Charles Darwin

Theory of natural selection (variation, overproduction, survival of the fittest).

Natural Selection

Process where species change; genes that are beneficial are more likely to survive and reproduce.

Artificial Selection

Humans choosing the traits they want in an organism (not natural).

Mutation

Change in DNA; the effect can be neutral, harmful, or beneficial.

Gene Flow

Individuals moving between populations, bringing new genes with them.

Genetic Drift

Random changes in genes, usually in small populations.

Founder Effect

Small group of people start a new population, making their genes different from the original.

Bottleneck Effect

Natural disaster/diseases reducing the original population.