G4 - Abnormalities in Sexual Reproduction

Question 1

sex chromosomes can be viewed in a

Answer 1

karyotype

Question 2

All non-sex chromosomes (#s 1-22) are called

Answer 2

All non-sex chromosomes (#s 1-22) are called autosomes

Question 3

factors that can impact meiosis and fertilization

Answer 3

meitoic erros and external errors

Question 4

non-disjunction

Answer 4

-one daughter cell having an extra chromosome and the other having a missing chromosome

happens when an entire chromosome can be lost or gained by cells if the homologous chromosomes fail to separate in anaphase I or II of meiosis I or II

In humans, this would result in gametes with 24 and 22 chromosomes, not the expected 23
This also means that the resulting zygote would have 47 or 45 chromosomes, not the expected 46, after fertilization

Question 5

how can non-disjunction be observed

Answer 5

use of a karyotype

During stages of cell division, chromosomes can be stained and photographed so they can be counted and compared
A picture of chromosomes that have been arranged according to number, size, shape, or some other characteristic is called a karyotype

Question 6

Trisomy

Answer 6

chromosomal abnormality in which there are three homologous chromosomes in place of a homologous pair

Question 7

Monosomy

Answer 7

chromosomal abnormality in which there is a single chromosome in place of a homologous pair

Question 8

Down syndrome is caused by

Answer 8

risomy 21, or having 3 copies of the 21st chromosome

-extra chromosome means there is an excess of genetic information

Question 9

Turner syndrome

Answer 9

One x and no Y chromosome

-many elad to miscarriages

Question 10

klinefelter syndrome

Answer 10

2 X and 1 Y sex chromosome

-exhibits feminine body traits

Question 11

patau syndrome

Answer 11

trisomy of chromosome 13

-rarley live a few months

Question 12

edwards syndrome

Answer 12

trisomy of chromosome 18 and life exptancay is less than 1 month

Question 13

In addition to karyotyping, genetic disorders can commonly be diagnosed prior to birth by

Answer 13

pre-natal testing

Question 14

CVS

Answer 14

Chorionic villus sampling (CVS) removes cells from the placenta for testing

Question 15

marking screening

Answer 15

assesses hormone levels in the mother’s blood to check for markers of increased risk of genetic conditions

Question 16

problems with fetilziation

Answer 16

Issues occurring with fertilization are much more common than chromosome abnormalities

• problemns with sperm or egg

-blocked fallopiean tubes

-blocked epididymis

Question 17

causes of improper fertilzation

Answer 17

Causes could include:
Poor or reduced egg or sperm quality or quantity
Blocked fallopian tube of the female
Blocked epididymis or vas deferens of the male

Question 18

Vitro Fertilization (IVF)

Answer 18

-folicule stimulating hormone given to overstimualted ovaries
-produces multiple eggs which will be collected by syringe before ovulation
-in lab egg is stripped of outer layer
- either it is incubated in sperm or needle is placed in egg and needle contains sperm
-can be put back in uterus when embryo forms

Question 19

Artificial Insemination

Answer 19

This is when sperm is placed into the reproductive tract of a female through a process called intrauterine insemination
A sperm sample, which can be fresh or frozen, is washed and concentrated and inserted directly into the uterus
This technique has also been used in non-humans to help save endangered species, including pandas