Final-12,13,14 Flashcards
What are the 3 phases of interphase in order?
G1 phase, S phase and G2 phase.
G1 phase
The cell grows
S phase
DNA is synthesized
G2 Phase
organelles are doubled and proteins are made
Mitosis
When the contents of the nucleus divide
Prophase during mitosis
Nuclear envelope disintegrates. Centrioles migrate to opposite sides. Asters form.
Metaphase during mitosis
chromosomes line up in the middle of the cell, in a random order.
Anaphase during mitosis
Sister chromatids separate and move to opposite sides of the cell
Telophase/cytokinesis during mitosis
The nuclear envelope starts to reform, the membrane pinches in and the cytoplasm divides.
What are the stages of mitosis in order
Prophase
metaphase
anaphase
telophase
cytokinesis
What does meiosis produce
Sex cells, or gametes
How many rounds of division are there in meiosis
2
What happens during meiosis in regard to the number of cells produced
One diploid parent cell will produce 4 haploid daughter cells, each genetically different from one another
What type of division is meiosis
A type of reduction division
Prophase 1 during meiosis 1
homologous chromosomes synapse. Genetic information is exchanged.
Metaphase I during meiosis 1
homologous pairs line up in the middle of the cell
Anaphase I during meiosis 1
homologous pairs of chromosomes separate
Telophase I/Cytokinesis during meiosis 1
nuclear envelope reforms and cytokenesis causes the cell to pinch off
Homologous chromosome
chromosomes which are the same size, have the same centromere location, and carry the same genetic information. Each chromosome from the male has a corresponding chromosome from the female.
What does chromosomes being homologous allow for
This allows for the exchange of genetic information whenever the 2 chromosomes touch
What happens by the end of telophase 1in meiosis 1
By the end of Telophase I the 2 daughter cells are haploid
After meiosis 1, why is meiosis 2 needed?
We just separated homologous chromosome pairs, but now we need to separate each arm of the chromosome, so that it has half the amount of genetic info.
Prophase II in meiosis II
nuclear envelope breaks down, spindle fibers form, centrioles migrate to opposite sides.
Metaphase II in meiosis II
Homologous chromosomes line up in the middle of the cell
Anaphase II in meiosis II
sister chromatids separate
Telophase II/cytokinesis in meiosis II
nuclear envelope reforms and cell breaks apart
Are the 4 daughter cells after meiosis the same?
All are genetically different
Chromatid
the arm of a replicated chromosome. Each arm of a replicated chromosome is a chromatid.
What happens to chromatids when they separate
When they separate, they are no longer chromatids, and are now chromosomes.
Kinetochore fibers
extend from the pole of the cell to the kinetochore region of the chromosome
Polar fibers
extend from the pole of the cell to the midline of the cell
What are the 2 types of spindle fibers
Polar fibers, kinetichore fibers
Tetrad
pair of homologous chromosomes synapsed
Synapsed
Paired together
What is the difference between plant and animal cells
Animal cell: has centrioles and asters, CM pinches in during telophase
Plant cell: no centrioles or asters, cell plate forms between two new nuclear areas during telophase
Uppercase letter
Dominant
Lowercase letters
Recessive
2 capitol letters
homozygous dominant
One capitol and one lowercase letter
heterozygous
Two lowercase letters
homozygus recessive
Self pollination
take pollen from male flower and dust it on to the female part of a flower of the same plant
Cross pollination
take the pollen from the male flower of one plant and dust in on to a female part of a flower on a different plant
Parental generation
P1
Monohybrid cross
a cross between one pair of contrasting alleles (pundit square has 4 offspring)
Dihybrid cross
a cross between 2 pairs of contrasting alleles (pundit square has 16 offspring)
Contrasting alleles
two different possibilities
Genotype
the actual genes after two alleles are crossed
Phenotype
how something looks after two alleles are crossed
Haploid
Cells with a single set of chromosomes
Diploid
a cell with two sets of homologous chromosomes
How do meiosis and mitosis differ in regards to types of reproduction
Mitosis can be a form of asexual reproduction, whereas meiosis is an early step in sexual reproduction
How do meiosis and mitosis differ in regards to the actual processes
They also differ in the way chromosomes move and the number of cell divisions
How do meiosis and mitosis differ in regards to the chromosomes in the daughter cell
In mitosis each daughter cell receives a complete diploid set of chromosomes. In meiosis, homologous chromosomes are separated, and each daughter cell receives only a haploid set of chromosomes.
How do meiosis and mitosis differ in regards to the number of daughter cells, and their genetic similarity.
Mitosis results in the production of two genetically identical diploid cells, whearas meiosis produces four genetically different haploid cells.
Synapsis
the pairing of two chromosomes that occurs during meiosis
Incomplete dominance
when a dominant allele doesn’t completely mask the effects of a recessive allele, so the organism shows a blending of both alleles
multiple alleles
more than 2 alleles in the population for that trait
Codominance
two alleles are expressed equally and produce traits of both
Polygenic traits
more than one gene contributes to the phenotype
Chromatin
genetic material of a cell that does not divide
Centromere
the region on a chromosome to where sister chromatids attach
Sister chromatid
one arm of a replicated chromosome
Kinetochore region
an area on a centromere to which a kinetochore fiber will attach
Principle of independent assortment
genes for different traits can segregate independently during the formation of gametes
What structures are found in the nucleus?
Chromosomes
What are located on chromosomes
Genes
What are chromosomes composed of
DNA wound around proteins
How do genes and chromosomes control the activity of the cell.
By producing proteins that regulate cellular functions or become part of the cell structure.
Why are DNA strands said to be complimentary?
Because each strand can be used to make the other strand.
Base pairing
The way each strand of the DNA double helix has all the information needed to reconstruct the other half.
How does DNA separate to prepare for DNA replication?
DNA molecule unwinds and separates into 2 strands. DNA helicase unwinds the DNA. DNA polymerase unzips the DNA.
How does DNA replicate?
Templates are made. DNA polymerase molecules move along the Templates, attaching complimentary base pairs and forming the sugar phosphate backbone.
What is each new DNA molecule composed of.
One new strand and one old strand.
How does DNA polymerase catch errors in DNA replication?
It proofreads the new strands as they are being created to catch errors.
What are genes
Coded DNA instructions that control the productions of protein within the cell.
Translation
How DNA makes RNA
mRNA
Carries the information from the DNA as to which proteins should be made.
tRNA
Carries amino acids
rRNA (ribosomal)
Site of protein synthesis.
Transcription
Separates the 2 strands of DNA and then uses one of the separated strands as a template to make RNA.
What does transcription require?
The enzyme RNA polymerase.
Translation
How RNA makes protein.
What are the 2 steps of translation
initiation and elongation.
Mutation
Any change in the DNA of a cell
Point mutation
Involves one nucleotide
Substitution
A mutation where one base is substituted for another.
Insertion
A type of point mutation where an additional base is added.
Deletion
A type of mutation where a base is removed
What might chromosomal mutations involve
changes in the number of chromsomes
Changes in the structure of chromosomes
Changes in the location of genes on chromosomes
Changes in the number of copies of some genes
Duplication
A segment of the chromosome is repeated
Inversion
when a part of the chromosome becomes oriented in the reverse of its usual direction
Translocation
When part of one chromosome breaks off and attaches to another chromosome.
Endocytosis
taking material into the cell by having it be packaged into a vesicle
Exocytosis
Moving material out of the cell by having it be packaged into a vesicle
What makes extra cells produced not cancerous
If extra cells produced behave like the other cells in their area, they aren’t cancerous
What makes extra cells produced cancerous
If they do not behave like the other cells in their area
Chiasmata
where 2 homologous chromosomes touch each other
What holds bases together in a DNA molecule
Hydrogen bonds
Transcription
When DNA makes RNA
translation
When RNA makes protein
Codon
3 nitrogen bases on an mRNA molecule
What is the start codon
AUG
What are the 3 stop codons
UAG, UGA, UAA
What does a match DNA
A matches T
what does g match DNA
G matches C
What DNA letters matches each other
A matches T and G matches C
RNA
a single stranded nucleic acid that contains the sugar ribose
What does RNA have that DNA doesn’t
RNA has uracil in place of thymine (U replaces T)
What matches with a in RNA
A matches with U
What RNA letters match each other
A matches U and G matches C
