genetics exam 1 (slides) Flashcards

It started in the 1950s and led to the description of the nucleus and the description of chromosomes.

He was the father of genetics, and he published an explanation of hereditary transmission in plants. He also studied pea plants

Correns, de vries, and von tschermak

Garrod in 1901

Bateson

Flemming, Sutton, and Boveri

1. Identification of the cellular and chromosomal basis of hereditary

2. Identification of DNA as hereditary material

3. Central dogma of biology

4. Genomic era

He talked about the chromosome theory of inheritance

They are long molecules of double-stranded DNA and protein,
which contain genes

They carry genes for a trait (in sexually reproducing organisms)

They both have DNA and chromosomes

Prokaryotic - an attachment site

Eukaryotic - histones, and a nucleus

plant and animals

plant

Watson, Crick, and Franklin

1960-1970s

In 1949 by Linus Pauling

focusing on the sequencing, interpretation, and comparison of genomes from different organisms

Focuses on the study of the complete set of proteins encoded in a genome

studies the complete set of genes that undergo transcription in a cell

studies chemical processes involving metabolites in a specific cell,
tissue, organ, or organism

overproduction and variation

inheritance

1. Phenotypic variation reflects genetic variation

2. Offspring inherit and express the alleles of their parents

3. Organisms carrying certain allele variants favored by
natural selection have a reproductive advantage over
those who do not

1. genetic mutation

2. gene flow

3. genetic drift

4. natural selection

It merges evolutionary theory with experimental, mathematical, and molecular population biology

1. Eukarya (true nucleus, multiple chromosomes)
2. Bacteria (no true nucleus, single chromosome)
3. Archaea (no true nucleus, single chromosome)

it viewed the traits in offspring as an intermediate mixture of the parental traits. (Mendel's results rejected this)

1. Make initial observations about a phenomenon or
process
2. Formulate a testable hypothesis
3. Design a controlled experiment to test the hypothesis
4. Collect data from the experiment
5. Interpret the experimental results, comparing them to
those expected under the hypothesis
6. Draw a conclusion and reformulate the hypothesis if
necessary

Controlled crosses, used pure-breeding strains to begin experimental controlled crosses, selection of dichotomous traits, quantification of results, and used replicate, reciprocal and test crosses

These are strains that consistently produce the same phenotype. (p, f1,f2 generation)

Pure-breeding individuals that have identical copies of the two alleles for a trait

The F1 plants had different alleles from each parent

Dominance of one phenotype over the other in the F1 generation.

100% dominance

1. Reemergence of the recessive phenotype in the F2 generation
2. A ratio of approximately among F2 phenotypes (3:1)

The theory stated that plants carry two discrete hereditary units(alleles) for each trait

the phenotype of the individual

a cross in which the two organisms crossed are both heterozygous for one gene. (G/g) x (G/g)

3:1 phenotypic ratio and a 1:2:1 genotypic ratio

A method of diagramming a genetic cross is a simple tool of genetic analysis

The law of segregation. It says the units of heredity, their separation into gametes, and the random union of the gametes into progeny in predictable proportions

The law of independent assortment. alleles of two or more different genes separate independently from the other into gametes that reproduce sexually (9:3:3:1 ratio)

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It is used to determine gamete genotypes and frequencies

Product rule(multiplication), sum rule, conditional probability, and binomial probability

If two or more events are independent of one another, the likelihood of their simultaneous or consecutive occurrence is the product of their individual probabilities

It defines the joint probability of occurrence of any two or more mutually exclusive events

It involves questions asked after a cross has been made and is applied when information about the outcome modifies the probability calculation

It predicts the likelihood of a series of events (for which there are two or more possible outcomes each time)

p = frequency of the outcome

q = frequency of the alternative outcome

(p+q)=1 (if there's only 2 outcomes)

(p+q)^n (can expand when n is the number of successive events)

It is used for quantifying how closely an experimental observation matches the expected outcome

X^2 = (O-E)^2/E

(O=observed, E=expected values)

The p (probability) value. low X^2 means high p value

It is the probability that the results of another experiment of the same size and structure will deviate as much or more from the expected results by chance

It helps determine the p-value. It is equal to the number of outcome classes, n, minus 1

rejected

the transmission of genes carried on autosomes, chromosomes found
in both males and females

22 - autosomes

1 - X or Y sex-determining chromosome

1. short generation (life) time

2. easy to grow and maintain in a restricted space

3. easy to understand development and growth

4. closely resembles other organisms

yeast, worms, fruitflies (D. melanogaster), zebrafish, mustard weed, and mouse

They are a way of tracing the inheritance of traits in humans and some animals

1. Males and females have the trait in approximately equal frequency
2. Each individual who has the trait has at least one parent with the trait
3. Either gender can transmit the trait to a child
4. If neither parent has the trait, none of their children will have it

1. Males and females have the trait in approximately equal frequency
2. Individuals who have the trait are often born to parents who do not (parents are heterozygous)
3. If both parents have the trait, all children will have it
4. The trait is not usually seen in each generation, rather it is typically seen among siblings

mRNA

Produces an enzyme that converts a linear starch molecule (amylose) into a complex, branched form (amylopectin). (has to do with seed shape)

The amylose

The Le gene

The Sgr gene

The b H L H gene

the process of cell division that produces two genetically identical daughter cells from one original parental cell

Interphase (G1, S phase, G2), prophase, prometaphase, metaphase, anaphase, and telophase

G1 - active gene expression/activity and preparation for DNA synthesis

G0- cell remains specialized by does not divide, will eventually die (apoptosis)

s phase - DNA is replicated and chromosomes are duplicated

G2 - prepares for cell division

Can pass through if the cell size is good and full or nutrients and growth factors are present

Can pass of DNA replication is completes and there is no base pair error

Can pass if the cell size is good and chromosome replication is successful.

Can pass if all chromosomes are attached to the mitotic spindle

A little in prophase but mostly in metaphase

Barrel shape structures that focus on the main microtubule organizing center.

They are small structures made of microtubules in the centrosome that help organize the microtubules.

The part that holds the chromosomes together. The help separate the sister chromatids during cell division

they are large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters.

they help provide an attachment site for chromosomes for cellular division

They are polarized structures with a minus end that help pull the sister chromatids apart.

They come from the centriole and help orient and position the spindle in the cell

a 4-subunit protein that coats sister chromatids along their entire length, with the greatest concentration at the centromeres

It is an enzyme that helps break down cohesin and separate the sister chromatids in anaphase

Produce genetically identical cells for growth and maintenance in somatic cells

They dont pair and rarely undergo recombination

Attach to spindle fibers from opposite poles in metaphase Separate and migrate to opposite poles at anaphase

Two genetically identical diploid daughter cells that continue to divide by mitosis

Chromatin condenses, making chromosomes and centromeres visible. The nucleus also disappears.

The nuclear envelope breaks down, and microtubules extend from opposite poles. Chromomses move towards the middle of the cell, and cohesin binds the sister chromatids.

Chromosomes are aligned in the metaphase plate and are fully condensed. The kinetochores and microtubules are fully extended, and the complete mitotic spindle is in place.

Anaphase A - Sister chromatids separate (disjunction), and the daughter chromosomes move towards the poles.

Anaphase B - polar microtubules extend in length

Daughter chromosomes reach the poles and from two new nuclei. Cytokinesis divides cytoplasm to create 2 new cells. (plants- cell walls/animal cells- cleavage furrow)

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diploid

Produce gametes for sexual reproduction that are genetically different in germ line cells

They fuse in prophase I, cross over in prophase I, and separate in anaphase I

They reduce to haploid numbers

1. Attach to spindle fibers from the same pole in metaphase I
2. Migrate to the same pole in anaphase I
3. Attach to spindle fibers from opposite poles in metaphase II
4. Separate and migrate to opposite poles in anaphase II

Four genetically different haploid cells that mature to form gametes and unite to form diploid zygotes

to separate homologous chromosomes

prophase I, metaphase I, anaphase I, and telophase I

leptotene, zygotene, pachytene, diplotene, and diakinesis

Chromosomes condense in leptotene, and meiotic spindle forms and extend out. The nuclear envelope disintegrates in zygotene. Homologous chromosomes fuses (synapsis). Crossing over occurs between nonsister chromatids and nuclear envelope continues to break down In pachytene. In diplotene, crossing over is complete, leaving the chiasmata to hold nonsister chromatids together. 4 chromatids of homologous pairs are visible, and the nuclear envelope is fully broken down. In diakinesis the mitotic spindle is established and tetrads move towards the middle of the cell.

the protein bridge that forms between homologous chromosomes

true

The chiasmata between homologs are resolved and crossing over is complete. Homologs align on apposite sides of the metaphase plate and kinetochore microtubules attach to both sister chromatids.

Sister chromatids are firmly attached by cohesin and homologs move to opposite poles of the cell

chromosomes gather at the poles of the cells and the cytoplasm divides.

Because of pseudoautosomal regions (PARs). There are 2 PARs on each chromosomes - PAR1 and PAR2

Separate sister chromatids (To divide haploid daughter cells into 2 haploid cells similar to mitosis.)

The nuclear envelope breaks down and centrosomes duplicate. Kinetochores and microtubules are produced, and chromosome recondensation takes place.

sister chromatids attach to kinetochore microtubules from opposite poles. The microtubule pull, and cohesin leads chromosomes to align on the metaphase plate.

Sister chromatids sperate after cohesin breaks down by seperase. When sister chromatids move towards opposite poles, polymerization of nonkinetochore microtubules elongates the cell

Chromosomes begin to condense, and the nuclear envelope re-forms. Cytokinesis separates newly formed nuclei and divides cytoplasmic material.

Sutton and Boveri

Morgan and to test Mendel's rules on natural species

the most common phenotype in a population

because they only have one X

The genetic and biological processes that produce the male and female characteristics of a species

It determines the gender based on the number of X chromosomes to sets of autosomes. Males - 0.5 and females -1

The SRY gene found on the Y chromosome (male) because it initiates the testicular development and without it the expression is female

True

Z/W system

Females - ZW

Males - ZZ

Females homozygous for the recessive allele and males hemizygous for it display the recessive phenotype. (more often in males)

Females heterozygous and males hemizygous for the dominant allele express the dominant phenotype

They are passed father to son

True

A mutation in the factor VIII gene on the X chromosome. The mutant allele produces a nonfunctional blood clotting protein

A rare X-linked dominant disorder that leads to a increase in the number of hair follicles on the body (affected males have more body hair than females)

Any mechanism that compensates for the difference in number of copies of genes between males and females. There are 4 different mechanisms

When one of the two X chromosomes in each female somatic cell is randomly inactivated in mammalian development.

It is also called the Lyon hypothesis.

The inactive X chromosome is visible near the nuclear wall.

Visualized by Murray Barr

When a person has 2 or more genetically different sets of cells. An example is cats

X inactivation in heterozygous females leads to a pattern of orange and black patches that is unique to each individual

XIST (X-inactivation specific transcript) and it can only act on the chromosome that is being transcribed.

It produces large R N A molecules that spread out and cover (or paint) the chromosome to be inactivated