Lectures 1 And 2 - Review

Question 1

What is a gene?

Answer 1

Come in multiple forms called alleles

Question 2

How does genetic information get transferred? Central dogma

Answer 2

DNA to RNA to protein

Question 3

When a cell isn’t dividing, what phase is it in?

Answer 3

Interphase

Question 4

Steps to mitosis?

Answer 4

Prophase - chromosomes condense, DNA doubles
Metaphase - cells line up at metaphase plate
Anaphase - chromatids gets pulled apart
Telophase/Cytokinesis - cell split into two identical daughter cells

Question 5

What are autosomes?

Answer 5

Chromosomes in human karyotype that aren’t sex chromosomes

Question 6

In mitosis, sister chromatids are…?

Answer 6

Identical

Question 7

What are homologous chromosomes?

Answer 7

Chromosomes that are the same shape/size, genes encoded, but don’t have to have the same alleles

Question 8

Stages of meiosis?

Answer 8

Start as 2n 46
Meiosis 1
Segregate homologous pair NOT SISTER CHROMATIDS - maternal apart from paternal

Meiosis 2
Just like mitosis, segregate sister chromatids
End as n 23

Question 9

Law of segregation?

Answer 9

During the formation of gamete, each gene separates from each together so that each gamete carries only one allele for each gene

Question 10

What is a non disjunction?

Answer 10

When sister chromatids don’t separate into two distinct gametes, they stay a full chromosome during meiosis 2

Question 11

What will happen to gamete that has non-disjunction?

Answer 11

Either die in embryo or be malformed or have disease

Question 12

Law of independent assortment?

Answer 12

Inheritance of one pair of genes is independent of inheritance of another pair

Question 13

What is gene linkage?

Answer 13

Alleles are on same chromosome instead of pair, independent assortment is not possible between genes that are on the same chromosome

Question 14

Pedigree symbols

Answer 14

Male - square
Female - circle
Affected - coloured
Unaffected - white/blank
Mating - single line
Consanguineous mating - double line
Generational line - vertical line

Question 15

What are the pedigree assumptions?

Answer 15

If the trait is rare, and autosomal recessive, then individuals who mate into the family pedigree are not carriers but are homozygous for the normal allele, unless there’s evidence to the contrary

Question 16

What is a recessive mutation?

Answer 16

Loss of gene function

Null/amorphic allele
1. Nonfunctional protein produced
OR
2. No protein is produced

Hypomorphic allele
1. Poorly functioning protein produced
OR
2. Reduced amounts of normal protein is produced

Question 17

What is the multiplication rule?

Answer 17

Multiply odds, AND

Question 18

What is the addition rule?

Answer 18

Add probabilities, OR

Question 19

What is an autosomal dominant trait?

Answer 19

recessive is normal phenotype, het or homozygous dominant is affected

Question 20

Dominant mutations?

Answer 20

Dominant hypermorphic allele
Negative consequences due to over production of protein
OR
Negative consequences due to protein with increased activity

Neomorphic allele
Negative consequences due to protein having a new function
Negative consequences when protein interferes with wild type protein

Question 21

Autosomal dominant traits are usually

Answer 21

Bb