BIOB11 - Molecular Biology

Mendel

Experimented w/ pea plants cross breeding

Genes

Mendel: Any given characteristic of a plant is governed by distinct units of inheritance called …

2

Each individual has … copies of a gene coming from each parent (inheritance)

Alleles

Alternative forms of genes

1

Each gamete contains … copy of the allele for a particular trait

Dominant

Allele determining the phenotype

Law of Dominance

Dominant will mask recessive in a heterozygote (3)

Segregated

Pair of alleles can be … during reproduction

Law of Segregation

Organism’s 2 alleles segregate from one another during gamete formation (3)

Flemming

Dude who observed cytoplasmic material distributing randomly to daughter cells during cell division

Chromosomes

Flemming: Nuclear material of eukaryotes became organized into visible threads & divided equally. The visible threads are …

Sutton

Dude who established concept of homologous chromosomes

Homologous, homologs

Each diploid cell has pairs of chromosomes called … chromosomes or …

Tetrads or bivalents

Homologous chromosomes can be either (… or …)

Synaptonemal complex

Homologous chromosomes (tetrads or bivalents) are held together by the …

Meiosis I

Meiosis I or Meiosis II?

Separates pair into different cells (reduction division)

Meiosis II

Meiosis I or Meiosis II?

Separates sister chromatids into 2 cells

Chromosomes

What are the physical carriers of genes?

Linear

Chromosomes have many genes arranged in a … sequence along DNA

Crossing over

Linked genes are not always inherited together because of … during meiosis

Eukaryotes

Eukaryotes or prokaryotes?

Linear chromosomes

Prokaryotes

Eukaryotes or prokaryotes?

Circular chromosomes

Linked

Genes located on the same chromosome may be … and tend to be inherited together (sans crossing over)

Crossing over

What allows for reshuffling of genes?

Chiasma

The point at which homologous chromosomes are crossed is called …

Kinetochore

Protein complex that helps pull apart chromosomes

Meiosis

Meiosis vs. Mitosis

Kinetochore pulls chromatid in same direction

Mitosis

Meiosis vs. Mitosis

Kinetochore pulls chromatid opposite poles

Griffith

Dude experimented with causative agent of pneumonia

DNA

The molecule that carries heritable information is …

Hershey-Chase

Which experiment confirms DNA (as heritable information)?

Deoxyribonucleic acid

Expand DNA

Adenine, thymine, guanine, cytosine

DNA is double helix with 4 different nucleotides

Sugar, phosphate backbone

Other than nucleotides, DNA is made up of alternate … and … (2)

Nucleosides

Sugar + nitrogeneous base

Nucleotides

Nucleoside + phosphate groups

Phosphodiester linkages

Nucleotides are joined together by 3’ — 5 … (2)

Phosphodiester linkages

Alternating sugar and phosphate groups holding nucleotides together are called … (2)

Hydroxyl

DNA:

3’ … on carbon 3

Phosphate

DNA:

5’ … on carbon 5

5’ to 3’

What is the directionality of each DNA strand? (3)

3

DNA base pairing:

G pairs with C in # hydrogen bonds

2

DNA base pairing:

A pairs with T in # hydrogen bonds

Chargaff’s Rules

Number of adenines always equal to number of thymines. Number of guanines always equal to number of cytosines. (2)

Variation

Chargaff’s Rules:

[A] + [T] DOES NOT EQUAL [G] + [C] for …

Right handed

DNA forms spiral to form a pair of … helices (2)

10

Each turn of the DNA helix is around # bases

Antiparallel

The 2 DNA strands run in opposite directions

One 5’ to 3’ and the other 3’ to 5’ making it …

Protein binding sites

The major/minor grooves of the DNA helix serve as … (3)

Genome

Complete store of organism’s DNA

20k

How many protein coding genes are in the human genome?

Genome

Where lay instructions for all RNAs and proteins?

Eukaryotes

Characteristic of…

DNA is enclosed in nucleus within nuclear envelope

Nuclear envelope

In eukaryotes, DNA in nucleus is enclosed within a …

Eukaryotes

Characteristic of…

Envelope contains 2 lipid bilayers

2

The nuclear envelope in eukaryotes are contained in # lipid bilayers

Nuclear pores

In eukaryotes, punctures along the lipid bilayers contain … (2) shutting across cytosol + nucleus

ER

Eukaryotes:

Outer membrane is continuous with the …

Filaments

Eukaryotes:

What supports the inner nuclear membrane?

Prokaryotes

Characteristic of…

Lacking specialized nuclear structure

Prokaryotes

Characteristic of…

Genes are on a single circular DNA molecule

RNA genes

Chromosomes that don’t make a protein but make an RNA

No

Is there a correlation between genome size and gene number?

Non-coding DNA

Multicellular species contains large regions of interspersed regions of DNA with unknown function called …

Gene expression

Large regions of DNA function to fine-tune … (2)

500

There are around # genes in bacteria vs. 20-25k in humans

Non coding DNA

What drives DNA variation across species, often in repetitive sequences?

1%

What percent of the genome codes for proteins?

Junk

Other than proteins, they are linked to the term … DNA

Spectral karyotyping

How do we visualize chromosomes? (2)

Hybridizing probes

Spectral karyotyping: Use of DNA … (2) attached to diferent flourochromes

Mitosis

Spectral karyotyping: Hybridizing probes can be designed to recognize a sequence on a specific chromosome during …

Chromosomal painting

What is commonly used to distinguish genetic diseases? (2)

Mitosis

Staining chromosomes with Giemsa during …

Giemsa

Other than special karyotyping, you can stain chromosomes with … during mitosis

Horizontal red line

Giemsa staining: What represents the position of the centromere? (3)

Chromatin

Giemsa staining: The banding patterns reflect variations in … structure under a light microscope

3.1 × 10^9

The human genome contains … nucleotide pairs

16k

How many nucleotides does the mitochondria contain in the human genome?

24

The human genome sequence has # chromosomes & mitochondria

Introns

Doesn’t code for proteins and are spliced out of RNA

Exons

Codes for proteins and don’t get spliced out

Regulatory DNA sequences

Promoters critical for gene expression (3)

Replicated, separated, partitioned

Functional chromosomes must contain genes that can be … (3 things) during cell division

Interphase

Gene expression is turned on during … for DNA replication, repair, etc.

Replication

Essential features of a chromosome:

There are multiple origins of …

One

Essential features of a chromosome:

How many centromeres?

Centromere

Essential features of a chromosome:

Holds duplicated chromosome together until ready for separation

Kinetochore, spindle fiber

Essential features of a chromosome:

What separates duplicated chromosomes? (2 things)

Two

Essential features of a chromosome:

One centromere but … telomeres

Telomere

Essential features of a chromosome:

Contains repeated nucleotide sequences for efficient replication

Cap

Essential features of a chromosome:

The repeated DNA sequences in telomeres protect chromosome ends acting like a …

2 meters

Total length of all 46 chromosomes is …

Folding

Total length of 46 chromosomes is 2 meters which fits by …

Linear DNA sequence, proteins

Folding happens because chromosomes have a … (3) and … that help

Chromatin

DNA with proteins are called …

Nucleus

Genome must be packaged in the … in order to fit

Billion

Diploid cells have 6.4 … bp of DNA in 46 chromosomes

1 bp = 0.34nm

6

1 bp binds # H₂O which expands in volume (genome packaging)