Module 2

Question 1

What biological process explains Mendel’s law?

Answer 1

Meiosis

Question 2

What are the products of segregation after meiosis?

Answer 2

4 chromatids

Question 3

What is segregation?

Answer 3

A mechanism to generate variability

Question 4

How many possible random segregation combinations are there for humans?

Answer 4

2^23 = 8,388,608

Question 5

What is the unit of segregation?

Answer 5

Chromosomes

Question 6

What is the determinant factor for male reproductive development?

Answer 6

SRY gene

Question 7

What are female chromosomes?

Answer 7

XX

Question 8

What are male chromosomes?

Answer 8

XY

Question 9

What would cause femaleness in XY individuals?

Answer 9

Deletion of the SRY gene

Question 10

What is an example of X-linked recessive?

Answer 10

Colour blindness and hemophilia

Question 11

What is an example of X-linked dominant?

Answer 11

Vitamin D resistant, brown teeth enamel

Question 12

What do gene mutations affect?

Answer 12

Typically one gene

Question 13

What is a large-scale chromosome change?

Answer 13

Chromosome mutation that affects many genes, leads to structural differences that can be detected using microscope

Question 14

What is a karotype?

Answer 14

A collection all chromosomes (with a specific number and structure) of a species or individual in condensed state

Question 15

What are cytogenetics?

Answer 15

Geneticists use stains to identify specific chromosomes and to analyze structures

Question 16

What is a euploid?

Answer 16

Having a chromosome number that is an exact multiple of a monoploid number (1n)

Question 17

What is a polyploid?

Answer 17

Extra copies of each chromosome of species (>2n, diploid, triploid, tetraploid)

Question 18

What is an aneuploid?

Answer 18

Abnormal number of one or more chromosomes

Question 19

What is the definition of monosomic?

Answer 19

One missing chromosome compared to 2n wild type

Question 20

What are the effects of polyploids?

Answer 20

Part of normal development of certain tissues and organisms (human muscle tissue, bone marrow

Question 21

What are the results of monoploids?

Answer 21

Part of normal development in some insects (wasps, bees), males are 1n, females are 2n

Question 22

What are the results of monosomic?

Answer 22

Part of normal development in some organisms, sex determination in some nematodes (XX and XO)

Question 23

What is autopolyploid?

Answer 23

All chromosomes originated from the same organisms

Question 24

What is allopolyploid?

Answer 24

One set of chromosomes originated from one organism and other from another, parent organisms need to be related to produce viable progeny

Question 25

Allopolyploidy in agricultural purposes

Answer 25

Mixing 2 genomes can lead to new phenotypes in offspring

Question 26

Autopolyploidy in agricultural purposes

Answer 26

Increasing ploidy levels can generate traits more valued by consumer

Question 27

How are autopolyploids generated naturally?

Answer 27

Naturally formed by mistakes in meiosis that lead to failure in executing one of the meiotic divisions and leads to gamete with twice as many chromosomes

Question 28

How are autopolyploids induced/created?

Answer 28

Formed by hybridization; crosses between 2 related species (mostly plants), can be formed by chemically fusing 2 cells

Question 29

What is the purpose of polyploid tissues in humans?

Answer 29

In some tissues, cells replicate DNA in S phase but not divide, leading to formation of polyploid tissue. eg) liver, heart, bone marrow, any smooth muscle

Question 30

What is aneuploidy?

Answer 30

The addition or loss of less than a full set of chromosomes or chromosome pairs

Question 31

What is monosomes?

Answer 31

One missing chromosome, in humans, autosomic monosomies die in utero; only one viable monosomy (Turner syndrome)

Question 32

What are trisomies?

Answer 32

one extra chromosome, in humans, only autosomic monosomies for large chromosomes die in utero, few viable trisomies (Klinefelter syndrome, down syndrome)

Question 33

Turner syndrome chromosomes

Answer 33

XO

Question 34

Turner syndrome characteristics

Answer 34

sterile females tall, slightly feminized poor facial hair growth small testis, female type pubic hair

Question 35

Down Syndrome is also known as

Answer 35

Trisomy 21

Question 36

Down syndrome effects which chromosome?

Answer 36

21 non-disjunction/translocation

Question 37

What is the idea of gene dosage?

Answer 37

Products of genes typically do not work in their own pathway, but interact with others to contribute to process or pathway

Question 38

What are some origins of chromosomal rearrangements?

Answer 38

Deletions, duplications, inversion, translocation

Question 39

What is needed for rearrangement of chromosomes to happen?

Answer 39

Should maintain most basic structure - have one centromere and two telomeres

Question 40

What happens after mitosis of normal chromosomes?

Answer 40

Normal splitting

Question 41

What happens after mitosis of dicentric chromosomes?

Answer 41

Break in chromosome loss, less viable

Question 42

What happens after mitosis of ascentric chromosomes?

Answer 42

no pulling forces, missegregation or chromosome loss

Question 43

What are unbalanced rearrangments?

Answer 43

Leads to change the gene number, can be caused by deletions and duplications, when they involve at least one gene

Question 44

What are balanced rearrangements?

Answer 44

Does not lead to changed gene number, will be arrangements that change gene order, like inversions and reciprocal translocations

Question 45

What is pseudodominance?

Answer 45

Recessive alleles uncovered by deletion will appear as if they are dominant, can lead to defects if deletion involves haploinsufficient genes

Question 46

What are the most common chromosomal rearrangements in humans?

Answer 46

Translocation

Question 47

Translocations can cause

Answer 47

New phenotypes

Question 48

What are proto-oncogene?

Answer 48

When mutated acquires novel activity to promote cancer

Question 49

What is Chromothripsis?

Answer 49

Genome chaos, generated clustered chromosome rearrangements are characteristic for tumor cells

Question 50

What is non-disjunction?

Answer 50

The failure of homologs (at meiosis) or sister chromatids (at mitosis) to separate properly at opposite poles

Question 51

What is a frameshift mutation?

Answer 51

The insertion or deletion of a nucleotide pair or pairs, causing a disruption of the translational reading frame

Question 52

What is translocation?

Answer 52

The relocation of a chromosomal segment to a different position in the genome

Question 53

What is an inversion?

Answer 53

A chromosomal mutation consisting of the removal of a chromosome segment, its rotation through 180°, and its reinsertion in the same location

Question 54

What is a dicentric chromosome?

Answer 54

A chromosome with two centromeres

Question 55

What is euploidy?

Answer 55

A complete chromosome set or an exact multiple of the haploid chromosome set

Question 56

What is polyploidy?

Answer 56

A chromosomal complement with at least three complete sets of homologous chromosomes