˗ˏˋ biology and genetics ´ˎ˗

Question 1

what is ancient DNA (aDNA)?

Answer 1

molecules that can be found on artifacts such as stone tools and cooking vessels that reveal more about the past.
- typically degraded (i.e., damaged) due to exposure to the elements such as heat, acidity, and humidity.

Question 2

what is the human genome project?

Answer 2

-began in 1990, completed in 2003.
- international, collaborative research program whose goal was the complete mapping and understanding of all the genes of human beings.
- all our genes together are known as our “genome.”

Question 3

what are proteins?

Answer 3

chain of amino acids that folds into a three-dimensional structure that allows a cell to function in a variety of ways.

Question 4

what are lipids?

Answer 4

• fatty acid molecules that serves various purposes in the cell, including energy storage, cell signaling, and structure.
• insoluble in water due to hydrophilic (water-loving) head and a hydrophobic (water-repelling) tail.

Question 5

what are carbohydrates?

Answer 5

molecules composed of carbon and hydrogen atoms that can be broken down to supply energy.

Question 6

what is nucleic acid?

Answer 6

a complex structure (like DNA or RNA) that carries genetic information about a living organism.

Question 7

what is deoxyribonucleic acid (DNA)?

Answer 7

• a molecule that carries the hereditary information passed down from parents to offspring.
• can be described as a “double helix”’ shape.
• includes two chains of nucleotides held together by hydrogen bonds with a sugar phosphate backbone.

Question 8

what is a DNA sequence?

Answer 8

• the order of nucleotide bases.
• can be short, long, or representative of entire chromosomes or organismal genomes.

Question 9

what is ribonucleic acid (RNA)?

Answer 9

• single-stranded nucleic acid molecule.
• different types found within cells and they perform a variety of functions, such as cell signaling and involvement in protein synthesis.

Question 10

who is robert hooke?

Answer 10

in 1665, observed slices of plant cork under microscope; he called what he saw cella, meaning “small rooms” in latin.

Question 11

what is a prokaryote?

Answer 11

a single-celled organism characterized by lack of nucleus and membrane-enclosed organelles.

Question 12

what is a eukaryote?

Answer 12

single-celled or multicelled organism characterized by a distinct nucleus, with each organelle surrounded by its own membrane.

Question 13

what is a microbiome?

Answer 13

the collective genomes of the community of microorganisms that humans have living inside of their body.

Question 14

what are organelles?

Answer 14

• a structure within a cell that performs specialized tasks that are essential for the cell. - different types each with its own function.

Question 15

what are archaea?

Answer 15

• a group of primitive prokaryotes that based on their distinct characteristics, form a separate domain from bacteria and eukaryotes.
• distinct evolution aside from bacteria.

Question 16

what are tissues?

Answer 16

a cluster of cells that are morphologically similar and perform the same task.

Question 17

what are animal cells?

Answer 17

• have a variety of different tissues.
• have skin, made of keratin, acts in same protective way.
• do not have a thicker membrane.

Question 18

what are plant cells?

Answer 18

• have a thicker membrane, made of cellulose.
• outermost layer forms a waxy cuticle to protect it.

Question 19

what is a phospholipid bilayer?

Answer 19

two layers of lipids that form a barrier due to the properties of a hydrophilic (water-loving) head and a hydrophobic (water-repelling) tail.

Question 20

what is cytoplasm?

Answer 20

the “jelly-like” matrix inside of the cell that contains many organelles and other cellular molecules.

Question 21

what is a nucleus?

Answer 21

double-membrane cellular organelle that helps protect DNA and also regulates nuclear activities.

Question 22

what is mitochondrion?

Answer 22

• specialized cellular organelle that is the site for energy production.
• has its own genome (mtDNA).

Question 23

what is adenosine triphosphate (ATP)?

Answer 23

a high-energy compound produced by mitochondria that powers cellular processes.

Question 24

what is mitochondrial DNA (mtDNA)?

Answer 24

circular DNA segment found in mitochondria that is inherited maternally.

Question 25

what is ribosomal RNA (rRNA)?

Answer 25

a ribosome-bound molecule that is used to correctly assemble amino acids into proteins.

Question 26

what is a nuclear envelope?

Answer 26

a double-layered membrane that encircles the nucleus.

Question 27

what is a mutation?

Answer 27

• an alteration to the base sequence of DNA; a nucleotide sequence variation from the template DNA strand that can occur during replication.
• mutations can also happen during recombination.

Question 28

what are molecular geneticists?

Answer 28

biologists that study the structure and function of genes.

Question 29

what are molecular anthropologists?

Answer 29

individuals who use molecular techniques (primarily genetics) to compare ancient and modern populations and to study living populations of humans and nonhuman primates.

Question 30

who is rosalind franklin?

Answer 30

• in 1953 discovered DNA structure, major for the scientific community.
• used x-ray crystallography.
• found the unique, double-helix shape.
• credit given to watson, crick and wilkins and received nobel prize in 1962.

Question 31

what are base pairs?

Answer 31

• chemical bonding between nucleotides, like adenine (A) and thymine (T) or cytosine (C) and guanine (G) in the DNA; or (A) and (U) in RNA.
• approximately three billion DNA base pairs in human cells.

Question 32

what are nucleotides?

Answer 32

the basic structural component of nucleic acids, which includes DNA (A, T, C, and G) and RNA (A, U, C, and G).

Question 33

what is the sugar phosphate backbone?

Answer 33

• a biochemical structural component of DNA.
• “backbone” consists of deoxyribose sugars and phosphate molecules.

Question 34

what is unique about DNA?

Answer 34

• highly organized.
• DNA from one human, stretched out is 2 meters (6.5 feet) long.

Question 35

what are histones?

Answer 35

protein that DNA wraps around to assist with DNA organization with the nucleus.

Question 36

what are chromatins?

Answer 36

• DNA wrapped around histone complexes.
• during cell division, chromatin becomes a condensed chromosome.

Question 37

what are chromosomes?

Answer 37

DNA molecule that is wrapped around protein complexes, including histones.

Question 38

what is euchromatin?

Answer 38

loosely coiled chromosomes found within the nucleus that is accessible for regulatory processing of DNA.

Question 39

how many pairs of chromosomes do humans have?

Answer 39

• 23 pairs of chromosomes (total 46) in each cell’s nucleus.
• different organisms have different numbers of chromosomes.

Question 40

what are centromeres?

Answer 40

• a structural feature that is defined as the “center” of a chromosome and that creates two different arm lengths.
• also refers to the region of attachment for microtubules during mitosis and meiosis.

Question 41

what are telomeres?

Answer 41

a compound structure located at the ends of chromosomes to help protect the chromosomes from degradation after every round of cell division.

Question 42

what is DNA replication?

Answer 42

cellular process in which DNA is copied and doubled.

Question 43

what is the cell cycle?

Answer 43

a cycle the cell undergoes with checkpoints between phases to ensure that DNA replication and cell division occur properly.

Question 44

what is semi-conservative replication?

Answer 44

DNA replication in which new DNA is replicated from an existing DNA template strand.

Question 45

what are the steps in DNA replication?

Answer 45

• initiation: the recruitment of protein to separate DNA strands and begin DNA replication.
• elongation: the assembly of new DNA from template strands with the help of DNA polymerases.
• termination: the halt of DNA replication activity that occurs when a DNA sequence ”stop” codon is encountered.

Question 46

what is helicase?

Answer 46

a protein that breaks the hydrogen bonds that hold double-stranded DNA together.

Question 47

what is a leading strand?

Answer 47

DNA template strand in which replication proceeds continuously.

Question 48

what is a lagging strand?

Answer 48

• DNA template strand that is opposite to the leading strand during DNA replication.
• created in several disconnected sections and other enzymes fill in the missing nucleotide gaps between these sections.

Question 49

what are DNA polymerases?

Answer 49

• enzyme that adds nucleotides to existing nucleic acid strands during DNA replication.
• can be distinguished by their processivity (e.g., DNA replication).

Question 50

what is mitosis?

Answer 50

the process that somatic cells undergo to divide which results in two diploid daughter cells.

Question 51

what are somatic cells?

Answer 51

diploid cells that comprise body tissues and undergo mitosis for maintenance and repair of tissues.

Question 52

what does it mean to be diploid?

Answer 52

refers to an organism or cell with two sets of chromosomes.

Question 53

what are homologous chromosomes?

Answer 53

a matching pair of chromosomes wherein one chromosome is maternally inherited and the other is paternally inherited.

Question 54

what are sister chromatids?

Answer 54

• during DNA replication, they are produced on the chromosome.
• in cell division, they are pulled apart so that two cells can be formed.
• in meiosis, they are also the sites of genetic recombination.

Question 55

what are gametes?

Answer 55

haploid cells referred to as an egg and sperm that will fuse together during sexual reproduction to form a diploid organism.

Question 56

what is meiosis?

Answer 56

the process that gametes undergo to divide which results in four haploid daughter cells.

Question 57

what is genetic recombination?

Answer 57

a cellular process that occurs during meiosis I in which homologous chromosomes pair up and sister chromatids on different chromosomes physically swap genetic information.

Question 58

what are chromosomal disorders?

Answer 58

• they occur in mitosis or meiosis.
• the 23rd pair of chromosomes in humans are what indicates biological sex.

Question 59

what is an aneuploid?

Answer 59

a cell with an unexpected amount of chromosomes. The loss or gain of chromosomes can occur during mitotic or meiotic division.

Question 60

what is karyotyping?

Answer 60

the microscopic procedure where the number of chromosomes in a cell is determined.

Question 61

what is down syndrome?

Answer 61

has three copies of the 21st chromosome.

Question 62

what is interphase?

Answer 62

preparatory period of the cell cycle when increased metabolic demand allows for DNA replication and doubling of the cell prior to cell division.

Question 63

what is klinefelter syndrome?

Answer 63

• xxy.
• a genetic condition in which a male is born with an extra copy of the X chromosome.
• lower testosterone and body hair.

Question 64

what is triple X syndrome; trisomy X?

Answer 64

• xxx.
• a genetic condition in which a female is born with an extra copy of the X chromosome.
• many women experience no side effects; most common is added height.

Question 65

what is turner syndrome?

Answer 65

• xo.
• a genetic condition in which a female is missing part, or all, of an X chromosome.
• symptoms include short stature, delayed puberty, infertility, heart defects, and certain learning disabilities.

Question 66

what is protein synthesis?

Answer 66

a multi-step process by which amino acids are strung together by RNA machinery read from a DNA template.

Question 67

what are the steps of protein synthesis?

Answer 67

• transcription: the process by which DNA nucleotides (within a gene) are copied, which results in a messenger RNA molecule.
• translation: the process by which messenger RNA codons are read and amino acids are “chained together” to form proteins.

Question 68

how many types of amino acids are there?

Answer 68

20.

Question 69

what is messenger RNA (mRNA)?

Answer 69

• RNA molecule that is transcribed from DNA.
• its tri-nucleotide codons are “read” by a ribosome to build a protein.

Question 70

what is splicing?

Answer 70

the process by which mature mRNAs are produced. Introns are removed (spliced and exons are joined together.

Question 71

what is a gene?

Answer 71

segment of DNA that contains protein-coding information and various regulatory (e.g.; promoter) and noncoding (e.g. introns) regions.

Question 72

what is RNA polymerase?

Answer 72

an enzyme that catalyzes the process of making RNA from a DNA template.

Question 73

what are introns?

Answer 73

segment of DNA that does not code for proteins.

Question 74

what are exons?

Answer 74

protein-coding segment of a gene.

Question 75

what is a ribosome?

Answer 75

-a n organelle in the cell found in the cytoplasm or endoplasmic reticulum.
- it is responsible for reading mRNA and protein assemblage.

Question 76

what are codons?

Answer 76

a sequence that comprises three DNA nucleotides that together code for a protein.

Question 77

what is transfer RNA (tRNA)?

Answer 77

• RNA molecule involved in translation. - transports amino acids from the cell’s cytoplasm to a ribosome.

Question 78

what is mendelian genetics?

Answer 78

a classification given to phenotypic traits that are controlled by a single gene.

Question 79

what is a genotype?

Answer 79

the combination of two alleles that code for or are associated with the same gene.

Question 80

what are alleles?

Answer 80

a non-identical DNA sequence found in the same gene location on a homologous chromosome, or gene copy, that codes for the same trait but produces a different phenotype.

Question 81

what is a punnett square?

Answer 81

• square diagram that is used to predict the genotypes of a particular cross or breeding experiment.
• named after reginald punnett, one of the first english genetics.

Question 82

what are heterozygous genotypes?

Answer 82

genotypes that consists of two different alleles.

Question 83

what are homozygous genotypes?

Answer 83

genotypes that consists of two identical alleles.

Question 84

what are cell surface antigens?

Answer 84

a protein that is found on a red blood cell’s surface.

Question 85

what are antibodies?

Answer 85

immune-related proteins that can detect and bind to foreign substances in the blood such as pathogens.

Question 86

what are codominance?

Answer 86

the effects of both alleles in a genotype can be seen in the phenotype.

Question 87

what is a pedigree?

Answer 87

a diagram of family relationships that indicates which members may have or carry certain genetic and/or phenotypic traits.

Question 88

what is a carrier?

Answer 88

an individual who has a heterozygous genotype that is typically associated with a disease.

Question 89

what is autosomal?

Answer 89

refers to a pattern of inheritance where an allele is located on an autosome.

Question 90

what is X-linked?

Answer 90

refers to a pattern of inheritance where the allele is located on the X or Y chromosome.

Question 91

what is incomplete dominance?

Answer 91

heterozygous genotype that produces a phenotype that is a blend of both alleles.

Question 92

what is a polygenic trait?

Answer 92

• a phenotype that is controlled by two or more genes (hair and eye color).
• human hair color is tied to melanin
• oculocutaneous albinism occurs when there are two non-functioning copies of the gene TYR, the hair skin and eyes have little, to no melanin or coloring.

Question 93

what are complex diseases?

Answer 93

a category of diseases that are polygenic and are also influenced by environment and lifestyle factors
(cardiovascular disease, schizophrenia, alzheimer’s).
- can run in families, but are currently not fully understood how or when they are passed through generations.

Question 94

what is pathogenic?

Answer 94

a genetic mutation (i.e., allele) that has a harmful phenotypic disease-causing effect.

Question 95

what is penetrance?

Answer 95

• the proportion of how often the possession of an allele results in an expected phenotype.
• some alleles are more penetrant than others.

Question 96

what is a genome?

Answer 96

all the genetic information of an organism.

Question 97

what is genotyping?

Answer 97

• a molecular procedure that is performed to test for the presence of certain alleles or to discover new ones
• how we learned that humans and chimpanzees (as well as bonobos) share a lot of DNA.

Question 98

what is sequencing?

Answer 98

a molecular laboratory procedure that produces the order of nucleotide bases (i.e., sequences).

Question 99

what is epigenetics?

Answer 99

• changes in gene expression that do not result in a change of the underlying DNA sequence.
• typically involve DNA methylation and histone modifications.
• changes are reversible and can also be inherited by the next generation.

Question 100

what is DNA methylation?

Answer 100

methyl groups bind DNA, which modifies the transcriptional activity of a gene by turning it “on” or “off”.

Question 101

what is an epigenetic profile?

Answer 101

• the methylation pattern throughout a genome – that is, which genes (and other genomic sites) are methylated and unmethylated.
• identical twins have their own epigenetic profiles, which become more different as they age.

Question 102

what is newborn screening?

Answer 102

• has been available in the US for over 50 years.
  -one of the first tests available was for a phenylketonuria (PICU/PKU) diagnosis.
• phenylketonuria(PICU/PKU) is birth defect that causes an amino acid called phenylalanine to build up in the body.
• untreated phenylketonuria can lead to brain damage, intellectual disabilities, behavioral symptoms, or seizures.
• it is treatable through dietary restrictions of protein.

Question 103

what is polymerase chain reaction (PCR)?

Answer 103

-molecular biology procedure that can make copies of genomic DNA segments.
- a small amount of DNA is used as a starting template and is then used to make millions of copies.

Question 104

what is sanger sequencing?

Answer 104

• a process that involves the usage of fluorescently labeled nucleotides to visualize DNA (PCR fragments) at the nucleotide level.
• several different types of alleles and genetic changes can be detected in DNA by using this analysis.

Question 105

what is direct-to-consumer (DTC) genetic disease testing?

Answer 105

• done without the guidance of medical professionals.
• should be used as a starting point for further testing of genetic diseases.
• no further help or information and can be difficult to interpret by nonmedical professionals.
• starting point for genetic carriers.
• can help guide lifestyle moving forward.

Question 106

how does direct-to-consumer (DTC) ancestry testing work?

Answer 106

• customers are genotyped.
• alleles assigned to different ethnic groups.

Question 107

what are the benefits and disadvantages of direct-to-consumer (DTC) ancestry testing?

Answer 107

• can help people who have lost their cultural ancestry.
• some sites partnered with law enforcement.
• results could change as the reference population grows.
• does not automatically provide cultural ties to those groups.