Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
67 Cards in this Set
- Front
- Back
Quantitative Interitance |
Polygenic inheritance |
|
Qualitative Inheritance |
Discreet Variation (one gene) |
|
Metacentric |
Centromere is in the middle |
|
Submetacentric |
Centromere is between middle and end |
|
Acrocentric |
Centromere is between middle and end but closer to the end |
|
Telocentric |
Centromere is at the end of the chromosome |
|
Mitosis |
Cell division used either for asexual reproduction or growth and repair of somatic cells |
|
Interphase |
Longest phase of cell cycle Chromosomes are extended and uncoiled; chromatin forms |
|
Prophase |
First phase of mitosis: Chromosomes coil up and condense; centrioles divide and move apart; the nuclear membrane breaks down
|
|
Prometaphase |
Second phase of mitosis: chromosomes are clear double structures; centrioles reach the opposite poles; spindle fibers form |
|
Metaphase |
Third phase of mitosis: chromosomes align individually in the center of the cell; centromeres attach to the spindle fibers |
|
Anaphase |
Fourth form of mitosis: centromeres split and daughter chromosomes begin to migrate to the opposite poles along the spindle fibers |
|
Telophase |
Final phase of mitosis: daughter chromosomes arrive at opposite poles; cytokinesis begins; spindle fibers break down; nuclear membrane forms |
|
Cytokinesis |
the division of cytoplasm between the daughter cells |
|
Meiosis |
the process of gamete formation; involves two stages of division |
|
Meiosis I |
Reductional division (2N --> N) |
|
Meiosis II |
Equational division (N --> N) |
|
Chiasmata |
Evidence of crossing over |
|
Crossing over |
The reciprocal exchange of chromosomal segments between non-sister chromatids of a homologous pair |
|
Prophase I |
Longest stage of Meiosis; broken into 5 stages. |
|
Leptonema |
Chromosomes begin to condense; chromosomes appear beaded; homology search begins |
|
Zygonema |
Rough pairing of homologous chromosomes; condensation continues; synaptonemal complex begins to form between homologues |
|
Pachynema |
condensation continues; synaptonemal complex is complete; homologue pairing referred to a synapsis; tetrads exist; crossing over occurs between non-sister chromatid within pairs |
|
Diplonema |
condensation continues; synaptonemal complex breaks down; homologous chromosomes held together by chiasmata between non-sister chromatids |
|
Diakinesis |
chromosomes are condensed; homologous chromosomes held together by chiasmata; nuclear membrane breaks down; spindle fibers form; centromeres attach to the spindle fibers |
|
Metaphase I |
homologues are paired; one homologue of each pair orients itself towards a random pole (random orientation) |
|
Anaphase I |
one homologue from each pair moves to opposite poles; centromeres do not divide |
|
Telophase I |
homologues are at opposite poles; cell begins to divide; cytokinesis begins |
|
Interkinesis |
A pause between phases; no change to DNA occurs |
|
Meiosis II |
almost identical to mitosis; results in 4 genetically unique haploid gametes |
|
Heredity |
the process by which living organisms produce offspring that resemble their parents |
|
Blending Inheritance |
There is an apparent so of variation in every generation |
|
Mendel's Initial Steps |
1. Establish true-breeding lines 2. Cross two true-breeding line to produce hybrids |
|
Mendel's Observations |
1. Only one version of the trait appeared in F1 hybrid 2. The form not seen in the F1 hybrid is the recessive gene 3. In F2, both versions of the trait appear 4. In F2, the dominant trait appears ~3x the recessive trait
F2 contains 1 true-breeding dominant, 2 hybrids, and 1 true-breeding recessive |
|
Mendel's Hypothesis |
1. Each trait is determined by heredity factors 2. Heredity factors are transmitted from parent to child through gametes 3. Each heredity factor has alternate forms 4. An organism has two copies of the heredity trait for each trait, one from each parent 5. The two copies of the heredity factor remain distinct properties 6. The two copies of the heredity factor are distributed singly and in equal proportions into the gametes 7. Gametes unite at random during reproduction |
|
Monohybrid Cross |
Examines 1 gene
1:2:1 genotype ratios 3:1 phenotype ratios |
|
Test Cross |
Crossing an individual with a dominant phenotype but unknown genotype with an individual who is a true-breeding recessive. |
|
Dihybrid Cross |
Crossing 2 genes 9:3:3:1 phenotype ratio |
|
Dihybrid Test Cross |
If dominant: all show dominant phenotype If hybrid: there is a 1:1:1:1 ratio of phenotypes |
|
Independent Assortment |
The segregation of the pairs of alleles for one trait occurs independently of the segregation of the alleles for the other trait during gamete formation |
|
Spermatogenesis |
The meiotic process by which sperm is created. It results in 4 sperm cells |
|
Oogenesis |
The meiotic process by which eggs are produced. It results in one ovum, with two polar bodies being formed along the way |
|
Polar Body |
A discarded cell that contains one of the nuclei of the division process, but almost no cytoplasm as a result of an unequal cytokinesis |
|
Probability |
1. The proportion of times that an event is expected to occur in repeated trials 2. Frequency of occurrence in a group |
|
Probability of an event in a single trial |
m/n
m: number of times that the event of interest occurs in n n: number of equally likely outcomes |
|
Addition Rule |
P(A or B) = P(A) + P(B) - P(A and B)
if A and B are mutually exclusive, then P(A and B) = 0, but this only occurs when looking at one gene |
|
Conditional Probability |
The probability that event B occurs, given that A has already occurred |
|
Multiplication Rule: |
P(A and B) = P(A) X P(B, given A)
If two or more traits are independent, as in independent assortment, then A has no effect on B so P(A and B) = P(A) X P(B) |
|
Pedigree Analysis |
Deduce the qualitative trait by examining the segregation of alleles in several generations of related individuals |
|
Complete Dominance |
Phenotypically, the heterozygous individual looks identical to the homozygous dominant individual |
|
Partial (incomplete) Dominance |
Phenotypically, the heterozygous individual is between the two homozygous individuals, but looks more like one than the other |
|
No Dominance (Additive Dominance) |
Phenotypically, the heterozygous individual is an exact intermediate of the two homozygotes |
|
Codominance |
Phenotypically, the heterozugous individual is an intermediate, but shows full expression of both alleles |
|
Multiple Alleles |
Three or more alleles for a particular gene exist in a population or species, but only two alleles can be present in an individual |
|
Lethal mutant Alleles |
The wild type gene product is needed in the correct amount for the survival of the organism |
|
Recessive lethal |
Homozygous recessive individuals die |
|
Dominant Lethal: |
Homozygous dominant and heterozygous individuals die due to possession of dominant allele |
|
Dominant morphology, but recessive lethal |
Homozygous recessive individuals die, but heterozygous individuals who a non-wild type morphology (ie. curly and antennapedia) |
|
Modified Monohybrid phenotype ratio |
No Dominance: 1/4 AA, 2/4 Aa, 1/4 aa |
|
Modified Dihybrid phenotype ratio |
1st gene shows complete dominance 2nd gene shows no dominance
Do branched out structure |
|
Epistasis |
1. The occurrence of novel phenotypes produced by the combined effects of two different genes on one trait 2. The genotype at one gene masks the effect or expression of the genotype at another different gene, where both genes affect the trait |
|
Recessive Epistasis |
If the individual is homozygous recessive at one gene, it masks the expression at the second gene
9:7 phenotype ratio |
|
Dominant Epistasis |
If the individual has at least one dominant allele at a gene, it masks the expression at the other gene
13:3 phenotype ratio |
|
Sex-Linked Traits (X-linked) |
Genes are actually on the X chromosome |
|
Sex-Associated patterns of inheritance |
Due to autosomal chromosomes, but linked with the gender of the individual |
|
Sex-Limited inheritance |
A trait that is expressed in only one sex even though the trait may not be X-linked |
|
Sex-Influenced Inheritance |
Phenotypic expression conditioned by the sex of the individual. A heterozygote may express one phenotype in one sex and an alternate phenotype in the other sex |