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Patterns of Chromosome Inheritance
Chapter 18
48
Biology
Undergraduate 2
03/26/2011

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Cards

Term
Humans have ______ chromosomes that are in ____ pairs within a cell's nucleus
Definition

 

46

 

23

 

Term
Pairs of chromosomes are called:
Definition
Homologous Chromosomes
Term
Autosomes are the 22 pairs of chromosomes that control:
Definition
traits that do not relate to gender of an individual
Term
Sex Chromosomes are the 1 pair that:
Definition
contain the genes that DO control gender
Term
Cells (body cells) that have 46 (2N) chromosomes are called:
Definition
Diploid
Term
Cells (sex cells) that have only 23 (N) chromosomes not in pairs are called:
Definition
Haploid
Term
Sex chromosomes are:
Definition
NOT homologous in males
Term

The cell cycle

 

1. Interphase:

Definition
  • G1 stage - cell doubles its organelles; cell grows in size

 

  • S stage - DNA replication occurs

 

  • G2 stage - proteins neeeded for division are synthesized
Term

The cell cycle

 

2. Mitosis

Definition
  • Nuclear division

Prophase

Metaphase

Anaphase

Telophase

Term

The cell cycle

 

2. Cytokinesis

Definition

 

  • cytoplasmic division
Term
Chromosomes contain both ____ and proteins (collectively called _________)
Definition

DNA and proteins

 

chromatin

 

Term
Chromosomes that are dividing are made up of 2 identical parts called
Definition
sister chromatids
Term
The sister chromatids are held together at a region called the:
Definition
Centromere
Term

THE SPINDLE IN MITOSIS

 

Centrosome

Definition
The microtubule organizing center of the cell
Term

THE SPINDLE IN MITOSIS

 

Aster

Definition
An array of microtubules at the poles (ends of the cell)
Term

THE SPINDLE IN MITOSIS

 

Centrioles

Definition
short cylinders of microtubules that assist in the formation of spindle fibers
Term

 

 

MITOSIS

Definition
  • A diploid makes and divides an exact copy of its nucleus
  • Used in cell growth and cell repair
  • Occurs in body cells
  • 4 phases
    • Prohase
    • Metaphase
    • Anaphase
    • Telophase
Term

 

 

EARLY PROPHASE

Definition
Centrosomes have duplicated. Chromatin is condensing into chromosomes, and the nuclear envelope is fragmenting.
Term

 

 

PROPHASE

Definition
Nucleolus has dissapeared, and duplicated chromosomes are visible. Centrosomes begin moving apart, and spindle is in process of forming.
Term

 

 

EARLY METAPHASE

Definition
Each chromatid is attached to a spindle fiber. Some spindle fibers stretch from each spindle pole and overlap.
Term

 

 

METAPHASE

Definition
Centromeres of duplicated chromosomes are aligned at the equator (center of fully formed spindle). Spindle fibers attached to the sister chromatids come from opposite spindle poles.
Term

 

 

ANAPHASE

Definition
Sister chromatids part and become daughter chromosomes that move toward the spindle poles. In this way, each pole receives the same number and kinds of chromosomes as the parents
Term

 

 

TELOPHASE

Definition
Daughter cells are forming as nuclear envelopes and nucleoli reappear. Chromosomes will become indistinct chromatin.
Term

 

 

MEIOSIS

Definition

 

  • occurs in sex cells
  • two nuclear divisions occur to make 4 haploid cells
  • used to make gametes (egg and sperm)
  • has 8 phases (4 in each meiosis I & II)
Term

MEIOSIS I

 

PROPHASE 1

Definition
Homologous chromosomes pair (synapsis) and crossing-over occurs in which there is exchange of genetic information
Term

MEIOSIS I

 

METAPHASE 1

Definition
Homologous pairs lined at the equator
Term

MEIOSIS I

 

ANAPHASE 1

Definition
Homologous chromosomes separate and move towards opposite poles
Term

MEIOSIS I

 

TELOPHASE 1

Definition
2 daughter cells result each with 23 duplicated chromosomes
Term

CROSSING OVER IN PROPHASE I

 

CROSSING-OVER

Definition

is the exchange of genetic information between nonhomologous sister chromatids during synapsis

 

This occurs during prophase I of meiosis and increases genetic variation

Term

MEIOSIS II

 

PROPHASE II

Definition

 

 

- Chromosomes condense again

 

Term

MEIOSIS II

 

METAPHASE II

 

 

Definition

 

 

- Chromosomes align at the equator

Term

MEIOSIS II

 

ANAPHASE II

Definition

 

 

-Sister chromatids separate to opposite poles

Term

MEIOSIS II

 

TELOPHASE II

Definition

 

 

- 4 daughter cells result each with 23 unduplicated chromosomes

Term

 

 

MITOSIS vs. MEOSIS

Definition

 

Growth and repair of cells            Formation of gametes

 

Occurs in body cells                    Occurs in sex cells

 

1 division                                  2 divisions

 

Results in 2 diploid                     Results in 4 haploid

genetically identical cells             genetically diff cells

Term

 

 

SPERMATOGENESIS

Definition

 

  • Process of making sperm in males
  • A continual process after puberty
  • about 400 million sperm are produced per day
Term

OOGENESIS

Definition

 

  • Process of makins eggs in females
  • During meiosis 1 egg and 3 polar bodies are formed
  • Polar bodies act to hold discarded chromosomes and thus disintegrate
  • Normally 1 egg per month is produced and ~500 during the entire reproductive cycle
Term

 

 

NONDISJUNCTION:

Definition
when both members of a homologous pair go into the same daughter cell during meiosis I or when sister chromatids fails to separate in meiosis II
Term

 

 

ANEUPLOIDY

Definition

 

  • An abnormal number of chromosomes, and is a type of chromosome abnormality

 

  • Having less than or more than 2 chromosomes
Term

RESULTS OF NONDISJUNCTION

 

MONOSOMY

Definition

cell has only 1 copy of a chromosome

e.g. Turner syndrome (only has one X chromosome)

Term

RESULTS OF NONDISJUNCTION

 

TRISOMY

Definition

cell has 3 copies of a chromosome

e.g. Down syndrome (3 copies of chromosome 21)

Term

CHANGES IN SEX CHROMOSOME NUMBER 

TURNER SYNDROME (X)

Definition

 

Short stature, broad shouldered with folds of skin on the neck, underdeveloped sex organs, no breasts

Term

CHANGES IN SEX CHOMOSOME NUMBER

 

KLINEFELTER SYNDROME (XXY)

Definition
underdeveloped sex organs, breast development, large hands and long arms and legs
Term

CHANGES IN SEX CHOMOSOME NUMBER

 

POLY-X FEMALE (XXX, XXXX)

Definition

 

- XXX tends to be tall and thin but not usually retarded

 

- XXXX are severely retarded

Term

CHANGES IN SEX CHOMOSOME NUMBER

 

JACOBS SYNDROME (XYY)

Definition
- tall, persistent acne, speech and reading problems
Term

CHANGES IN CHOMOSOME STRUCTURE

 

DELETIONS

Definition
loss of a piece of the chromosome (e.g. Williams syndrome)
Term

CHANGES IN CHOMOSOME STRUCTURE

 

TRANSLOCATIONS

Definition

 

 

movement of chromosome segments from one chromosome to another nonhomologous chromosome (Alagille syndrome)

Term

CHANGES IN CHOMOSOME STRUCTURE

 

DUPLICATIONS

Definition

 

 

presence of a chromosome segment more than once in the same chromosome

Term

CHANGES IN CHOMOSOME STRUCTURE

 

INVERSIONS

Definition

a segment of a chromosome is inverted 180 degrees
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