BIOL 3000 Genetics - Auburn Dr. S - Exam 1

Spontaneous generation

living structures form without descent from similar organisms

Preformationism

organisms develop from miniature versions of themselves

Homunculus

tiny human curled up inside sperm

Pangenesis

body cells and structures shed small pieces of themselves which collect in the reproductive organs prior to fertilization (gemmules)

Blended inheritance

Inherited traits are determined randomly from a range defined by the two parents

Lamarckism

an organism can pass characteristics it has acquired throughout its lifetime along to its offspring

Rat tail mutilation

study that disproved lamarckism

Epigenesis

the embryo is not preformed in the ovum or the sperm, but that it develops gradually by the successive formation of new parts from information passed down

Heredity

transmission of traits from one generation to the next

Expression

once you get genetic material, how do you convert that into a phenotypic character

What is life?

Complexity, growth and change, adaption, responding to stimuli

Macromolecules of life

C N P O H S

Macros of carbohydrates and lipids

C, H, and O

Macros of nucleic acids

C, H, O, N and P

Macros of protein

C, H, O, N, S

Transforming principle

What did the griffith experiment with rats and rough and smooth strains determine?

Transformation requires DNA

What did the Avery, MacLeod & Mccarthy experiment determine was the heredity material?

Radioactive protein phages

How did Hershey and chase determine that DNA was the heredity material?

DNA components

phosphate, sugar, base

Chargaff's rule

he NUMBER OF GUANINE units equals the NUMBER OF CYTOSINE units and the NUMBER OF ADENINE units equals the NUMBER OF THYMINE units

Nucleotides

Units of DNA

Purine

double ring nitrogenous base (AG)

Pyrimidine

singe ring nitrogenous base (TCU)

Phosphoric Acid

What is a nucleoside missing?

Ant, syn

____ configuration is favored by purines however, ____ configuration can be formed and actually has a role in formation of Z‐DNA

Outside

Phosphate molecules on the _____?

Inward

Bases point_____, perpendicular to the helical axis

Hydrogen bonds

What links base pairs?

No

Are bases coplanar?

B-DNA

Hydrated form of DNA

A-DNA

Dehydrated form of DNA, bases are tilted, molecule is much wider and shorter

Z-DNA

Left-handed DNA with zig-zag pattern, repeating CG, in both syn and anti configurations, bases are still pointed inside molecule, more compact

Surface area

Why do cells divide versus growing bigger?

DNA Replication

process by which genetic information is duplicated; ensure that each cell in an organism has a complete and correct copy of the organism's genome or genetic data

G0

resting phase / cell senescence

G1

growth phase; cell increases in size and prepares for DNA synthesis

S

DNA Replication

G2

growth phase; cell increases in size and prepares for mitosis and cell division

M

cell growth stops and cell divides into two daughter cells

Conservative Model

both parental strands stay together after DNA replication and the daughter molecules contain all new nucleotides

Semi‐Conservative Model

the double stranded DNA contains one parental and one daughter strand following replication (Watson and Crick's model)

Dispersive Model

parental and daughter DNA are interspersed in both strands; consists of old and new strands

High-fidelity

Characteristic of DNA that makes little errors in replication

Origin of replication

250 bais pair of AT

Bi-directionally

How does DNA replicate?

Topoisomerase

(gyrase) reduce torsional strain causing unwinding of double helix

Single‐strand Binding Proteins

stabilize ssDNA until elongation begins

Helicase

breaks hydrogen bonds between complimentary nucleotides

Primase

RNA polymerase that adds a ribonucleotide primer to ssDNA

Primers

typically 10‐12 bases in length

DNA pol I

removes RNA primer and starts synthesis

DNA pol III

responsible for most of replication process

5 to 3

DNA polymerase can ONLY synthesize DNA in ____ direction

Cannot, RNA primer

DNA polymerase (can/cannot) initiate DNA synthesis by itself; Requires addition of _____

One

DNA polymerase moves in ____ direction

DNA Ligase

joins together newly synthesized DNA strands by creating a covalent phosphodiester bond

Telomeres

complex of repetitive DNA and proteins found at the terminal ends of eukaryotic chromosomes

Phosphodiester bond

What kind of bond is formed between the % prime phosphate group of and one nucleotide and the 3 prime hydroxyl group of the adjacent nucleotide?

DNA Polymerase

Which enzyme is the most active during the replication of DNA?

2

After replication, chromosomes consist of how many molecules of DNA?

3

During DNA replication, nascent DNA strands are synthesized in only one direction. Nucleotides are added ONLY to which end of the growing nascent strand?

degenerate/redundant

There are sixty one different codons that code for amino acids, but only twenty different amino acids. This means that the genetic code is _____.

Helicase catalyzes ATP hydrolysis and DNA strands separation, so the helix cannot be unwound and strands will not separate.

DNA helicase inhibitors are well studied as potential drug targets. What would you expect to see if DNA helicase activity is inhibited?

Leading strand

What is the term for the daughter strand synthesized continuously during DNA replication?

Promotors

What are the DNA regulatory sequences recognized by RNA polymerase called?

True Breeding (Pure Breeding)

always passes down certain phenotypic traits to its offspring

Reciprocal Cross

cross between male of one strain and female of another, AND vice versa

Filial Generation

related to one's offspring

GENE

discreet particle of inheritance/DNA sequence

ALLELE

alternative forms of a gene (eg. Rr)

GENOTYPE

combination of alleles an individual has (RR, Rr, etc.)

PHENOTYPE

physical appearance of a trait (round, wrinkled)

HOMOZYGOTE

individual having the same alleles (RR, rr)

HETEROZYGOTE

individual having different alleles (Rr)

LOCUS

physical location of any gene on a chromosome

LOCI

physical location of any two or more genes on a chromosome

DOMINANT

phenotype 1 is dominant to phenotype 2 if the F 1 heterozygote has phenotype 1

RECESSIVE

phenotype 2 is recessive to phenotype 1 if the F1 heterozygote has phenotype 1

MONOHYBRID CROSS

mating between two individuals with alleles at a single locus (R on one chromosome (P1) X r on one chromosome(P2))

MENDEL'S THIRD LAW

Idea of Dominance; The trait from one allele will mask the trait of another allele.

Mendel's Second Law

independent assortment; During gamete formation, when two or more alleles are inherited, individual alleles assort independently of one another giving different traits an equal opportunity of occurring.

MENDEL'S FIRST LAW

Segregation of Alleles; Every individual has two alleles for a trait (diploid). During formation of gametes, the alleles separate and offspring randomly receive an allele from each parent.

AA x AA

All AA

aa x aa

All aa

AA x aa

Aa

Aa x Aa

1 AA : 2 Aa : 1 aa; 3 A_ : 1 aa

Aa x aa

1 Aa : 1 aa; 1 A_ : 1 aa

Aa x AA

1 Aa : 1 AA; All A_

Chromosome Theory of Inheritance

correctly explains the underlying mechanism of Mendelian genetics by combining chromosomes with the paired factor postulated by Mendel.

genetic linkage in the fruit fly

Theory stated that inheritance patterns may be generally explained by assuming that genes are located in specific sites on chromosomes.

Chromatin

DNA exists as ____ and must be in a "loose" configuration to be accessed.

HOMOLOGOUS CHROMOSOME

paired chromosomes having same genes (alleles) for the same trait (phenotype) located at the same place (loci) on the chromosome

Aren't

The two chromosomes in a homologous pair ____ always identical to each other

Mitosis

When one cell divides and form two IDENTICAL cells

Cytokinesis

process during cell division when the cytoplasm of a single cell is divided to form two daughter cells

MEIOSIS

process in which the number of chromosomes in a cell is halved during the production of germ cells (gametes)

Meiosis I

results in two (2) "Haploid" daughter cells, each with half the number of chromosomes as the original

Meiosis II

results in four (4) Haploid (n) gametes

Crossing over

exchange of genetic information between non‐sister chromatids

Incomplete Dominance

Expression of the heterozygote phenotype forms an intermediate that is distinct from either parent