Meiosis and mendelian genetics, Population Genetics, DNA and RNA, and Animal Development
Many single-celled organisms, cinludeing all prokaryyotes, reproduce by__________-or the splitting of a cell in two.
Some single celled and simple multi-celled eukaryotes reproduce asexually by _______. In this process, one or several cells will break off the parent and become a new individual.
Any of the alternative versions of a gene that produce distinguishable pheotypic effects.
The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts.) In most cases, the offspring are genetically idential to the parent.
A chromosome that is not directly involved in determining sex; not a sex chromosome
A lineage of genetically identical individuals or cells. To make one or more genetic replicas of an indvidual or cell.
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.
A cell containing two sets of chromosomes (2n), one set inherited from each parent.
A descrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses)
A cell containing only one set of chromosomes (n).
A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes of the same characters at corresponding loci. One_______ chromosome is inherited from the organism's father, the other from the mother.
The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosomes sets as the orginal cell.
The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.
The pairing and physical connection of replicated homologous chromosomes during prophase I of meiosis.
Examples of asexual reproduction in plants are; ____, ______, and _____ (runners).
bulbs, rhizomes, and stolons (runners)
3 differences between meiosis and mitosis
1. Cells pass through each phase twice and cytokinesis twice (Meiosis I and II) so the end result is for cells.
2. DNA replication only happnes once, but cells divide twice, so the resulting cells are haploid.
3. During prophase I, the processes of synapsis and crossing over occur.
When the two sets of sister chromatids from one homologous pair of chromosomes get bound together and intertwine.
Right after synapsis, where chromosome pieces are swapped between chromatids thereby increasing genetic variability.
The end result of meiosis is _____, known as ______ (eggs and sperm). In plants, the cells are known as _____.
four haploid cells, gametes , spores.
The speicific process of sperm formation is called
A major difference from males to females in terms of the production of functional gametes during meoisis is;
cytokinesis is uneven, so that one large and three small cells are produced in females. The large one is the ovum (egg) and the other three are the polar bodies. Males produce 4 even haploid sperms 4(n)
the specific process of ovum formation in females is called
The ______ develops inot the the new individual by repeated mitosis and cytokinesis.
The study of inheritance
DNA molecules with protein, which determine cell/organism structure and function
Sections of DNA that code for synthesis of enzymes that regulate cell reactions to determine character
a specific cell activiy or appearance
expressed variations of specific character are
the genetic variations that produce traits are called
alleles (one allele per trait)
The major patterns of genetic inheritance include:
two or more genes work together to produce a specific outcom
Mendel found what 4 things?
1. There are alternative forms of genes (alleles) for each trait
2. for each inherited trait a diploid organism receives two genes (one from each parent)
3. a gamete (sperm or egg) carries only one allele because homologous chromosomes separate dring meiosis (law of segregation)
4. for those traits inherited by complete dominance, one allele of the pair is usually expressed (dominate) while the other is not (recessive).
alleles that are the same; a genotype
alleles that are different; a genotype
physical expression of a genotype---a character has variable traits
genetic- A gene for a character has variable alleles for the traits
character is to_____ as gene is to____.
character is to trait as gene is to allele
If an individual that is homozygous dominant for a gene mates with an individual that is homozygous recessive, that is a __________.
monohybrid cross--All of the offspring will be heterozygous all expressing dominate trait.
A ________ involves parents that are homozygous (one parent dominate, one parent recessive) for two different genes.
"if the genes are located on different chromosomes, the inheritance of one will no affect the inheritance of the other" is called
Law of Independent Assortment
Reductional division occurs in
equatorial division occurs
during meiosis II
the study of the changes in genotype and allele frequencies that occur in natural populations
a group of individuals of the same species, co-occurring in a specific location at a specific time
a group of individuals that share common characteristics and that which, under natural conditions, can interbreed and produce fertile offsrping
For any one species, the sum of genetic variability for that species is referred to as its
the frequencies of the dominant allele and recessive allele (and therefore, the frequencies of the genotypes) remained unchanged generation after generation is known as it's;
a mathematical principle that states that allelic and genotypic frequencies in a population remain constant unless acted upon by forces other than genetic recombinations and the law of segregation
Hardy-Weinberg (H-W) equilibrium theory
In order to be in equilibrium, the following assumptions must be met:
1. Large population size
3. No Natural selection
4. No migration
5. No mutation
6. No genetic drift
individuals in a population do not select their mates...mate at random
refers to the effects of an environment on a species; species adapt in order to respond to these changes. Where nature selects the adaptations that allow survival.
any alteration of teh nucleotide sequence in a gene.
refers to random changes in allele frequencies that may result from processes such as founder effect or bottleneck effect
refers to the reproductive isolation of some protion of an existing population
results from a catastrophic decline in the population size that may be caused by an unusual abiotic factor like a hurricane or tornado that kills most of the population
what is formed by crossing over and occurs in prophase I
centrioles duplicate and begin to move to opposite poles
G2 phase of interphase
At interphase the ________cell number is_______
BLANK contains one 5 carbon sugar (pentose), one phosphate functional group an one nitrogen containing ring molecule called a BLANK
nucleotide and nitrogenous base
DNA contains the pentose sugar called BLANK, while RNA contains BLANK
deoxyribose and ribose
The phosphate functional group is attched at the BLANK
DNA contains the nitrogenous bases ?, ?, ?, and ?
Adenine, Guanine, Cytosine, and Thymine
RNA contains the nitrogenous bases ?,?,?, and ?
A, G, C, and Uracil
The two bases A and G are formed as double ringed molecules and are collectively known as ?
Purines (pure as gold)
The three bases C, T, and U are all single ringed nitrogenous bases called
Any nitrogenous base in either DNA or RNA attaches at the ? position of the pentose
The process where DNA is exactly duplicated during S phase of interphase is called ?
Three key characteristics that faciliate the replication or repair of a DNA molecule
Complementary Base Pairing- (A to T and G to C)> Chargaff's Rule
Anti-parallel arrangement of strands- (3' and 5' ends ALIGNED in opposite directions
Semi-conservative nature of synthesis- unzipping or breaking of the H bonds at the base pairs in order to replicate DNA molecule
??? occurs at multiple locations simultaneously and works in both directions along the strands by the actions of ???
DNA polymerase can only move alone a strand of DNA from the ?? towards the ?? end of the nucleotide. It arranges the complementary nucleotides in the new strand in a ?? to ?? alignment.
Since replication occurs in BOTH directions, when the strand separate, they form an opening called a
A series of replication bubbles open all along the DNA at postions called
At each end of a replication bubble is a
The portions of the strands that are aligned 3'->5' AWAY from the initiation site and TOWARDS the replication forks
Leading strand (continuous synthesis)
The portions of the strands that are aligned 3->5' TOWARDS the initiation site and AWAY from the replication fork creating a gap is
Lagging strand (discontinuous)
Daughter DNA molecule contains one ?? and one ??
old and new strand
Highly coiled strands of RNA fond in ribosomes. Function as the site in a ribosome where polypeptides are assembled ie protein synthesis.
Ribosomal RNA (rRNA)
Found in free molecules in the cytoplasm. Function to bring amino acids to the ribosome and transfer them to the ribosome to be added to the polypeptide (protein) being synthesized.
Transfer RNA (tRNA)
created in the nucleus (eukaryotes) or cytoplasm (prokaryotes) as a copy of a gene. It is a single strand of RNA whose length varies according to the size of the gene that is copied.
The process of mRNA formation as one copy of one gene from a DNA molecule is called
A special enzyme that copies one gene from one strand (the sense strand) of DNA from 3' to 5' (makes new single strand by adding complementary nucleotides in an antiparallel strand)
When RNA polymerase reads T on DNA, it brings in ?, when it reads C, it brings ?, when it reads G, it brings ?, but when it reads A, it brings ? instead of ?
A, G, C, U instead of T
When the RNA polymerase gets to the ? region, it lets the new mRNA go. The mRNA then moves to a ribosome to begin the process of ?
The process of converting the information in the mRNA which is formed by specific base sequences, into a polypeptide chain or protein. Also known as protein sythesis. Occurs at ribosomes either within the nucleus or at the rough endoplasmic reticulum in eukaryotes.
Translation (protein synthesis)
The information in the bases is read as base triplets called ??, there are 64 of these, three of which are known as nonsense of stop ? because they are found at the end of the mRNA and signal the end to building the specified protein. The other 61 specify a specific amino acid.
one specific codon , ??, not only signals for a specific amino acid called methionone, it also signifies the start of progein synthesis, thus it is always the FIRST codon on mRNA
codons are read at the ribosome by rRNA at a location called the
The corrrect amino acid is brought to the ribosome by tRNA which has an exposed three base sequence called an
anticodon (must match codon for amino acid to be kept)
The amino acids at the ? and ? sites are joined by a ? bond.
A and P
phosphate functional group
RNA ribose Sugar
The sections that are joined by DNA ligase
Okazaki fragments (created from lagging strand)
Uracil has ? strands and has ?? molecular forms
1 strand, 3 molecular forms
thymine (pyrimdine) has ?? strands, ?? molecular forms
Development in animals consists of 4 major phases:
Penetration of the sperm into ovum and fusion of haploid (n) gamete nuclei to form a single elled diploid (2n) zygote is called
Cleavage progresses through the following stages...