U2 Definitions

Question 1

DNA

Answer 1

Polymer with 2 strands composed of sequences of the nucleotide bases

Question 2

Chromosome

Answer 2

2 molecules of DNA packaged by histone proteins

–> Each half (unreplicated) chromosome has ONE DNA molecule

–> We have 2 of each chromosome
–> 23 Pairs (46 altogether)

Question 3

Duplicated Chromosome

Answer 3

–> X shape
–> 2 molecules of DNA

Question 4

Chromatid

Answer 4

1/2 of the chromosome

–> ONE dna molecule

Question 5

Gene

Answer 5

A segment of DNA on a chromosome that is transcribed

–> The information: they DO NOT do make anything (the recipes)

–> Have both coding and non-coding regions

Question 6

Transcription

Answer 6

The process of producing an RNA molecule from a DNA segment

–> RNA polymerase makes an RNA copy of the DNA = mRNA

Question 7

Allele

Answer 7

A version of a gene

–> Each chromosome pair has the same genes but may differ in alleles

–> One of the pair contains alleles inherited from mother and other in the pair contains alleles inherited from father

Question 8

Homozygous

Answer 8

Two alleles for a gene are the same

Question 9

Heterozygous

Answer 9

Two alleles for a gene are different

Question 10

Genotype

Answer 10

Genetic makeup

–> DNA sequences of chromosomes and the 2 alleles carried for genes

Question 11

Phenotype

Answer 11

Any observable characteristics or trait of an organism/cell

Question 12

Translation

Answer 12

Converting mRNA sequence to an amino acid sequence

–> Ribosomes translate the mRNA to produce chains of amino acids –> Leads to protein folding

Question 13

Protein Folding

Answer 13

Results in final conformation of protein

Question 14

Process of getting from genotype to phenotype

Answer 14

Genotype —-> Protein —-> Phenotype

Question 15

Coding vs Non-Coding Regions

Answer 15

Coding = Encodes for gene products

Non-Coding = Instructions for WHEN, HOW MUCH, and IN WHAT cells to transcribe genes

Question 16

Proteins

Answer 16

Polymers of amino acids connected by peptide bonds

Question 17

Non-Coding Region Functions

Answer 17

Determine the amount, the time, and the location (in what cells) of transcription

–> Essentially determines level of expression of a gene (which is determined by amount of protein)

Question 18

Allele Transcription

Answer 18

BOTH alleles are transcribed, just some are transcribed more than others –> Producing different amounts of proteins (difference between recessive and dominant)

Question 19

Gene Regulatory Switch

Answer 19

A short sequence (~5-20 base pairs) of DNA in the non-coding region of a gene

–> Where TRPs bind
–> The “light switch”

Question 20

Transcriptional Regulatory Protein

Answer 20

TRP: Proteins that bind to gene regulatory switches that either activating or repressing transcription

Question 21

Cell Diversity

Answer 21

All cells have the same gene regulatory switches, but not all cells have the same TRPs needed to interact with those switches

–> Leads to cell differentiation

Question 22

“Dimmer Switch” of Gene Regulatory Switches

Answer 22

Most genes are regulated over a range of expression levels between repressed, intermediate, and high levels of expression

–> Due to the fact that gene regulatory switches usually have multiple bindings sites for TRPs

Question 23

Binding of TAP to Gene Reg. Switch

Answer 23

Enables RNA polymerase to interact with coding region –> Activates transcription

Question 24

Promoter

Answer 24

Specific coding sequence adjacent to beginning of a coding region

(regulatory switch does not need to be next to promoter)

Question 25

Mutation

Answer 25

A change in the nucleotides of a DNA molecule

“The factory of variation production” –> Main source of genetic variation

–> Mutations occur at every cell division
–> Occur randomly and are UNAVOIDABLE (majority of mutations are NOT from radiation/environment)

Question 26

Point Mutations

Answer 26

Most common type of mutation: Single nucleotide changes

Question 27

Duplication Mutations

Answer 27

One or more copies of a DNA segment is produced, duplicating a sequence when it shouldn’t be

Question 28

Germ-Line Mutations

Answer 28

Mutations that occur in cells giving rise to gametes

–> These mutations are passed down to offspring

Question 29

Somatic Mutations

Answer 29

Mutations that occur in body cells (not gametes)

–> These mutations are NOT passed down to offspring

Question 30

Mitosis

Answer 30

Process by which a cell divides into two identical daughter cells

–> Diploid daughter cells

Question 31

Meiosis

Answer 31

The process by which humans and most animals produce gametes

–> Daughter cells are haploid (only contain one of two alleles)

Question 32

Recombination

Answer 32

Creates new combinations of alleles in gamete DNA

–> A physical exchange of DNA between copies of the same chromosome

Question 33

Independent Assortment

Answer 33

Creates diverse recombinations of chromosome copies among gametes produced by an individual

–> Occurs in meiosis to produce genetic variation