Lecture 1b: Mend. Inheritance and Chromosome Transmission Flashcards
congenital analgesia is a __ trait in humans
recessive (homologous)
Two individuals heterozygous for the
congenetal analgesia plan
to start a family and want to have 3 kids.
What is the probability that all three
of the couple’s children will
have congenital analgesia?
Pp x Pp
- Individual probability: 1/4
- For three kids: 1/4 x 1/4 x 1/4= 1/64
Usually contain a single type of circular chromosome
Prokaryotes
Regulates nutrient uptake and waste excretion
Cytoplasm
Chromosomes in prokaryotes are found where
nucleoids
Outside the membrane of prokaryotes there is a
rigid cell wall
Doesn’t contain a nucleus
Prokaryotes
Reproduce Asexually by Binary Fission
Prokaryotes
Then the cell divides into two daughter cells by a process termed
binary fission
Function of FtsZ protein
recruits proteins to create a new cell wall
Contains most of the genetic material in the form of linear chromosomes
Eukaryotes
Have membrane-bounded organelles with specific functions
Eukaryotes
The field of genetics that involves the microscopic examination of chromosomes
cytogenetics
Cytogenetics allows what to occur?
the detection of individuals with abnormal chromosome number or structure
provides a way to distinguish between two closely-related species
Cytogenetics
A karyotype is the ___ chromosomes photographed and arranged from
largest to smallest.
mitotic
Chromosomes are told apart about
banding patterns
Karyotypes are rarely seen in what phase
anaphase
Karyotypes, banding patterns, are more visible in ___ than ___
prometaphase, metaphase
A human chromosome has, on average, about
1,100 genes
Members of a pair of chromosomes are called
homologues
The two chromosomes in a homologous pair are
same size and same genes, dif alleles
Since different chromosomes can be about the same size and have about the same centromere position, chromosomes are treated with stains to produce characteristic banding patterns: Example….
G-banding
In G-bandings, chromosomes are exposed to what dye
Giemsa
What regions are stained well and what regions don’t bind to the stain well
Well: dark bands
Not well: Light bands
Giemsa binds ___ to stain chromosomes
DNA
Banding patterns in prometaphase vs. metaphase
Prometaphase: longer bands and darker stains
At the centromere of a chromsome, intense compacted areas have what colored bands
lighter
have more bands than metaphase chromosomes because chromosomes continue to be condensed during the progression of mitosis
prometaphase chromosomes
Chromosomes only have a rod shape in
mitosis
In interphase: G1, S, G2 is what percent DNA and protein
50% both
Mitosis has what percent protein and DNA
Protein: 2/3
DNA: 1/3
Chromatids are made up of
dna and proteins
All cells in your body, most besides gamete, are
2n
The 2n cell is replicating its DNA to become
4n
cell in the GO and G2 phase are
not dividing
Cell enters replication as ___, then into G2 as ___, then in mitosis it __
2n, 4n, splits into 2n
Mitotic spindle is made up of
microtubules
Pairs of sister chromatids align themselves along a plane in what phase
metaphase
In metaphase, each pair of chromatids is attached to both poles by
kinetochore microtubules
The connection holding the sister chromatids together is broken in what phase
anaphase
Each chromatid, now an individual chromosome, is linked to only one pole in what phase
anaphase
Kinetochores MTs shorten and chromosomes move to opposite poles
Anaphase
Chromosomes reach their respective poles and decondense and Nuclear membrane reforms to form two separate nuclei
Telophase
Cytokinesis in plants vs. animals
In animals: formation of a cleavage furrow
In plants: formation of a cell plate
In mitosis, the two daughter cells are ___
genetically identical to each other
ensures genetic consistency from one cell to the next
mitosis
The development of multicellularity relies on the repeated process of
mitosis and cytokinesis
The process of forming gametes
gametogenesis
what is produced meiosis
haploid (1n) cells are produced from diploid (2n) cells
Like mitosis, meiosis begins after a cell has progressed through
interphase of the cell cycle
Unlike mitosis, meiosis involves ___ successive divisions
two
are organized along the metaphase plate
bivalents
Pairs of sister chromatids are aligned in a ___ row, rather than a ___ row (as in mitosis)
double. single
The orientation in meiosis I is
random
During anaphase of meiosis I, two pairs of sister chromatids separate from each other. The connection that holds sister chromatids together…
does not break
Meiosis II occurs when?
telophase and cytokinesis
In spermatogensis, with meiosis I begins with ____ and ends with ____
In meiosis II, it begins with ___ and ends with ____
4n to 2n
2n to n
Unlike spermatogenesis, the cytokinesis in oogenesis is
asymmetric
In oogensis, what is the product
1 egg and 3 polar bodies
In spermatogensis, the products are…
4 haploid sperm cells
