Meiosis & Karyotyping Flashcards
What do chromosomal mutations involve?
They involve changes in the whole chromosome
Error in Meiosis: Nondisjunction
failure of chromosomes to separate properly causes aneuploidy=abnormal chromosome number
What are the type is nondisjunction in meiosis?
trisomy and monosomy
Trisomy
Extra chromosome
monosomy
missing chromosome
Down syndrome
Extra #21 chromosome (47 chromosomes)
Turner’s Syndrome
Missing Sex chromosome-45 chromosomes (XO=Female)
Klinefelter’s Syndrome
EXTRA sex chromosomes-47 (XXY Male)
Patau
47 chromosomes, extra #18
Edward’s
47 chromosomes, extra #13
Deletion
When a part of chromosome is left out
Insertion
When a pat of a chromatid breaks off and attaches to its sister chromatid. The result is a duplication of genes on the same chromosome
Inversion
When a part of one chromosome breaks off and reattaches backwards
Translocation
When part of one chromosome breaks off and is added to a different chromosome,
Cri du chat
deletion of #5
Huntington’s Disease
4 repeats 40 times
Testosterone
regulates development and secondary sex characteristics
How long does sperm development last?
begins at birth and continues until death
What happens during the menstrual cycle?
Hormones are released to help an egg in the follicle mature
What does estrogen do to the lining of the uterus?
Causes the lining to thicken to prepare for the egg
What happens after the egg ruptures from the follicle?
Progesterone is released to further thicken the uterine lining and increase blood supply
How long is a menstrual cycle?
28 days
Menstruation causes the lining of the uterus to_______ if no fertlization of the ______ occurs
shed, egg
what happens in the follicular phase?
The hormones FSH and LH are released causing the follicle to mature. Cells around the dgg produce estrogen which causes the lining of the uterus to thicken (egg is finishing meiosis II)
When does ovulation occur?
midway through the cycle and lasts 3-4 days.
What does the sudden release of FSH and LH cause the follicle to do?
Rupture and release the egg into the fallopian tube
How many eggs to the ovaries release a month?
1
What is the luteal phase?
Where the egg moves through the fallopian tube. (The ruptured follicle turns yellow (corpus lutetium) and then it releases progesterone. This will increase the thickness of the uterine lining (endrometium) and increase it blood supply
What is semen?
Collection of sperm and fluid
Where does sperm travel when going toward the egg?
Through the uterus, and into the fallopian tube
how does the sperm find the egg?
It is attracted to chemicals made by the egg
How long can sperm live?
20-30 hours
How do sperm eat through the coating on the egg
with special enzymes
What is a new cell called?
zygote
when the zygote begins to inmediately divide, this is called….
cleavage/mitosis
What is a gene
a segment of DNA info that codes for a trait
Where are genes found?
DNA chromosomes
what is a gamete
sex cell
What is the goal of meiosis?
to separate the two sets of genes so that each gamete contains just one set of chromosomes
A cell that contains both sets of homologous chromosomes is said to be….
diploid
