Bio lesson 1.4 key terms

Question 1

What is non-disjunction

Answer 1

failure of paired chromosomes to move to opposite poles of the spindle during mitosis or meiosis.

Question 2

What does non-disjunction result in

Answer 2

Leads to abnormal number of
chromosomes in daughter cells

Question 3

Define trisomy

Answer 3

Chromosomal abnormality with three homologous chromosomes in a pair of

Question 4

Define Monosomy

Answer 4

Chromosomal abnormality with a single chromosome in place of a homologous pa

Question 5

What are the most common trisomies (autosomes)

Answer 5

Trisomy 21 (Down Syndrome)
Trisomy 18 (Edwards Syndrome)
Trisomy 13 (Patau Syndroms)

Question 5

What are the most common trisomies (sex cells)

Answer 5

XXY (Klinefelter Syndrome)
XYY (Jacobs Syndrome)
XXX (Triple X Syndrome)
XYY (super male)

Question 6

What is XO

Answer 6

When there is only 1 x-chromosome that is genetically identified in a female (Turner Syndrome)

Question 7

Define Karyotype

Answer 7

Karyotype displays chromosomes in a single cell by number and size.

(White blood cells extracted, stimulates mitosis, stops metaphase, photo gets taken when chromosomes is the most condensed and then sorted)

Question 8

What is prenatal testing

Answer 8

Prenatal testing is a test for a genetic disorder that occurs before birth that involves a blood test

Question 9

At what age are prenatal testing recommended

Answer 9

Recommend for pregnant women over the age of 35 or based on family history

Question 10

What are the types of prenatal testing and describe them

Answer 10

Amniocentesis (Amniotic fluid,
fluid surrounding the fetus, is extracted)

Chorionic Villus Sampling (Cells from the chorion, a part of the placenta, is
extracted)

Multiple Marker Screening (Tests for hormone levels associated with certain medical conditions)

Question 12

What are controversies and issues associated with prenatal testing?

Answer 12

Could carry risks on the person getting the test (miscarriage but depends on the test) or could be expected of the person but they may not want it

Question 13

Errors caused by Changes in Chromosome Structure and the issues during crossing over

Answer 13

Deletion, Duplication, Translocation, Inversion

Question 14

Explain the issue, Deletion

Answer 14

Cri Du Chat: Deletion of chromosome 5

Question 15

Explain the issue, Duplication

Answer 15

Charcot-Marie-Tooth: Duplication on chromosome 17

Question 16

Explain the issue, Translocation

Answer 16

FG Syndrome: Inversion of x chromosome

Question 17

Explain the issue, Inversion

Answer 17

Chronic Myelogenous Leukaemia: Translocation of chromosome 9 and 22

Question 18

What are some Examples of monosomy in humans

Answer 18

Phenotypically female, Infertility and Absent menstruation