Cell Cycle Flashcards
(33 cards)
How Chromosomes is formed?
i. In the nucleus of each cell, the DNA molecule is packaged into the thread like structure called chromosomes.
ii. Each chromosome is made up of DNA tightly coiled many times around histones that support its structure.
This are highly alkaline found in eukaryotic cell nuclei That package and order the DNA into structural units called?
Nucleosome
Internal structure of histone
Histone two each: H2A, H2B, H3, H4
Anatomy of chromosome
Telomere
Short arm
Centromere
Longer arm
Sister Chromatid
Caps at the end of each strand of DNA that are chromosomes;
Without this DNA strand become damaged and cells can’t do their job
Telomere
The region of chromosome to which the microtubules of the spindle attach, via the Kinetochore, during cell division.
-Point of attachment of the Kinetochore
Centromere
Cri-du-Chat Syndrome
Down syndrome
47, XXXY (Klinefelter syndrome)
Turner Syndrome
Williams Syndrome
Chromosomal abnormalities
Errors during dividing of sex cell
meiosis
Errors during dividing of other cells
Mitosis
-Is a group of symptoms that result from missing a piece of chromosome
-Short arm of chromosome 5
-It is an autosomal deletion syndrome caused by a partial deletion of chromosome 5P and is characterized Buy a distinctive, high-pitched, facial abnormalities, and mental retardation thru out life.
Cri-du-Chat Syndrome
Chromosomal Condition that is associated with the
:intellectual disability,
characteristic facial appearance and
weak muscle tone in infancy
-Typically caused by non-disjunction
-Trisomy 21 is caused by an error in cell division
Down syndrome
Genetic condition in which a human male has an extra male (Y), Giving it total of 47 chromosomes
-occurs during cell division
Klinefelter Syndrome
Chromosomal condition that alters development in females.
-unable to conceive a child because of an absence of ovarian function.
-Occurs when one of the two (X) chromosomes normally found in women is missing or incomplete
Turner Syndrome
A developmental disorder that affects many parts of the body.
-Characterized by a
:mild to moderate intellectual disability’s or learning problems,
:unique personality characteristics,
:distinctive facial features, and
:heart and blood vessel problems. -Caused by deletion of additional genetic material near the elastic gene on chromosome 7
Williams Syndrome
Breakage of the chromosomes can lead to four types of changes in chromosome structure
Deletion
Duplication
Inversion
Translocation
It occurs when a chromosome fragment lacking a centromere is lost during cell division
Deletion
It occurs when a fragment becomes attached as an extra segment to a sister chromatid
Duplication
It occurs when of chromosomal fragment reattaches to the original, psalm but in the reverse orientation
Inversion
A chromosomal fragment joins a nonhomologous chromosome
Translocation
— is an orderly set of stages that take place between that time a cell divides and the time resulting daughter cells also divide.
— It is controlled by internal and external signals like a molecule that stimulates or inhibits a metabolic events.
The cell cycle
CC stages:
Is a process in which a cell may double its entire content in preparation for cell division
Interphase
The cells contents are distributed in two daughter cells
M-phase
During this stage, the cell carries on its regular activities, and it also gets ready to divide if it is about to complete the cell cycle.
G1 phase -growth
S phase - Dna Synthesis
G2 phase - Growth and preparation for mitosis
Interphase
a period when the cell increases in size in preparation for cell division. RNA and proteins including enzymes needed for making DNA synthesized
Gap 1 Phase
