Unit 4 - JC Flashcards
They carry genetic materials to be inherited by offspring.
Chromosomes
Who coined the term chromosome meaning “colored bodies”?
Wilhelm Waldeyer
Provided first evidence that germ cell chromosomes imparted continuity between generations
Note: His work on Ascaris embryos provided one of the first descriptions of meiosis.
Theodor Boveri
Described the configurations of individual chromosomes in cells at various stages of meiosis (testes of Brachystola magna)
Note: Confirmed and expanded upon Boveri’s observations
Walter Sutton
Carried traits from one generation to the next
Mendelian factors
Recognized and explored the fibrous network within the nucleus-termed chromatin or “stainable material”
Walther Flemming
Whose experiments provided the physical basis of the Mendelian law of heredity?
A. Flemming and Waldeyer
B. Bridges and Flemming
C. Sutton and Boveri
D. Morgan and Bridges
C
Helped establish the chromosomal basis of heredity and sex
Calvin Bridges
Experimentally demonstrated Chromosomal Theory of Inheritance using Drosophila melanogaster - pioneered “Fly Room” experiments
Thomas Hunt Morgan
Greatly contributed to the discovery of sex chromosomes and association between specific genes and specific chromosomes
A. Flemming and Waldeyer
B. Bridges and Flemming
C. Sutton and Boveri
D. Morgan and Bridges
D
Boveri and Sutton’s experiments led to what theory?
Chromosomal Theory of Inheritance
Threadlike structures made of protein and a single molecule of DNA
Note: They are factors that distinguish one species from another
Chromosomes
True or False?
Chromosomes come from “chroma” and “soma” which means color and body, respectively.
True
Enable transmission of genetic information from one generation to the next
Chromosomes
Chromosomes, in _________
Ensure daughter cell retain its own complete genetic complement
Mitosis
Chromosomes, in _________
Enable each mature ovum and sperm to contain a unique single set of parental gene
Meiosis
In a ‘normal’ human being, how many chromosomes are there?
46
Human chromosomes contain how many autosomes?
44
Human chromosomes contain how many pairs of sex chromosomes?
1
Other DNA materials found in mitochondria
Extra-chromosomal DNA
Chromosomes that have the same sequence of genes and the same structure
Homologous chromosomes
True or False?
Mitochondria are not capable of replicating on their own, despite having their own DNA.
False
Replicated condensed chromosome with sister chromatids
Note: Become condensed and visible under the microscope.
Metaphase Chromosome
Proteins that are responsible for the first level of DNA packing in chromatin. Forms core for the DNA.
Histones
A complex molecule containing the genetic information that makes up the chromosomes.
DNA
Repeating subunit of chromatin fibers, consisting of DNA coiled around histones
Note: DNA + Histones
Nucleosome
A group of six nucleosomes
Solenoid
Clusters of solenoids
Chromatin
Formed by coiled chromatin; half of a chromosomes
Chromatid
Formed by two sister chromatids
Chromosome
Central region which is the primary constriction where sister chromatids are linked. Responsible for
Note: Consists of several hundred kilobases of repetitive DNA chromosome movement at cell division.
Centromere
Organelles located at the centromere region (MOTC) and it facilitates spindle formation
Kinetochore
Portion of chromosome that is designated as p (petite)
Short arm
Portion of chromosome that is designated as q (queues) or g (grande)
Long arm
12p16
A. Short arm
B. Long arm
A
12p16
What specific region in the chromosome is indicated?
16
12p16
What chromosome number is indicated?
12
12p16
This denotes the _____ of a specific gene.
Locus
Chromosomes that have a single centromere.
Monocentric
Chromosomes that lacks a centromere.
Acentric
Chromosomes that have two centromeres
Dicentric
Which of the following types of chromosomes reliably transmit from parental to daughter cells?
A. Monocentric
B. Dicentric
C. Acentric
D. Both B and C
A
Which of the following types of chromosomes are genetically unstable because they cannot be maneuvered properly during cell division and are usually lost?
A. Monocentric
B. Dicentric
C. Acentric
D. Both B and C
C
Which of the following types of chromosomes are genetically unstable because they are not transmitted in a predictable fashion?
A. Monocentric
B. Dicentric
C. Acentric
D. Both B and C
B
Chromosomes that have centromeres that are centrally located yielding arms of roughly equal length.
Metacentric
Chromosomes that have centromeres that are off-center yielding arms of unequal length.
Submetacentric
Chromosomes that have centromeres very close to one end yielding a very small short arm.
Note: Often associated with small pieces of DNA called satellites which encodes rRNA.
Acrocentric
Small pieces of DNA in acrocentric chromosomes that encode rRNA.
Satellites
What does “acro” mean?
Peak
Chromosomes that have centromeres located at the terminal end.
Note: These are not found in humans.
Telocentric
How many pairs of metacentric chromosomes are found in humans?
5
(1, 3, 16, 19, 20)
How many pairs of submetacentric chromosomes are found in humans?
13
(2, 4-12, 17-18, X)
How many pairs of acrocentric chromosomes are found in humans?
5
(13-15, 21, 22, Y)
How many pairs of telocentric chromosomes are found in humans?
0
What is the chromosome type?
Arm length ratio: 1.0-1.6/1.7
Metacentric
What is the chromosome type?
Arm length ratio: 3.1-6.9
Subtelocentric
What is the chromosome type?
Arm length ratio: 3.0
Submetacentric
What is the chromosome type?
Arm length ratio: 7.0
Acrocentric
What is the chromosome type?
Arm length ratio: Not acceptable
Telocentric
Tip of each chromosomes
Telomere
Human telomere hexameric sequence
TTAGGG
Lasso-like structure at the end of a telomere that serves to protect the termini of a chromosomal DNA molecule from end-to-end fusions and degradation by exonucleases.
T-loop
Which is not a function of telomeres?
A. Prevent abnormal end-to-end fusion
B. Protect ends of chromosomes from degradation
C. Ensure complete DNA replication
D. Have a role in chromosome pairing during meiosis
E. Serve as primary constrictions where sister chromatids are linked
E
