introduction- lecture 1

Question 1

moore’s law

Answer 1

in terms of the cost of genetic sequencing:

The cost of sequencing roughly followed a Moore’s law trajectory in the decade before 2008, but the introduction of NGS technologies caused costs to drop faster than would be expected by Moore’s law

Question 2

why do new mutations tend to be from men instead of women

Answer 2

women are born with all the eggs they’ll have in their lifetime, while men will continue to produce sperm (the older the man, the more of a chance of mutations that will be passed on to offspring)

Question 3

tasmanian devil facial tumor disease

Answer 3

the devil population bottlenecked because of this- died really quickly but the devil tumors had the same genetic makeup despite devils having unique dna

shows that tumor was transmissible (passed on with bite) and tasmanian devils were so close to each other genetically due to bottleneck that immune systems couldnt distinguish self from non self and kill tumor

tried to isolate some, develop vaccines, but natural selection did the work for them because susceptible genotypes died and resistant genotype alive

Question 4

mitochondrial dna sequence

Answer 4

mitochondrial dna helps make phylogenetic tree, so we can see who has a common ancestor

Question 5

karyotype

Answer 5

number and appearance of chromosomes in a cell

Question 6

congenital insensitivity to pain

Answer 6

inhibits ability to perceive physical pain

Question 7

nociceptors

Answer 7

special nerve cells in the body dedicated to sensing pain

Question 8

pedigree analysis symbols

Answer 8

Question 9

genotype of an individual

Answer 9

its set of alleles: Genes are inherited from an offspring’s parents, and they are responsible for features being passed down from one generation to the next. An organism’s genotype consists of its entire set of genes. Every human has a unique genotype, which explains the vast variety in human appearance and biology.

Question 10

an individual who is AA or aa is

Answer 10

homozygous (both alleles are the same)

Homozygotes code for the same trait, for instance, blue eyes. If you have two blue eye alleles, your eyes will be blue. But if you have one allele for blue eyes and another for brown eyes, your eye color will be dictated by whichever allele is dominant.

Question 11

alleles

Answer 11

Genes are chunks of DNA that contribute to particular traits or functions by coding for proteins that influence physiology. Alleles are different versions of a gene, which vary according to the nucleotide base present at a particular genome location.

A dominant allele is one that always determines the phenotype when present. On the other hand, a recessive allele is one that is not expressed when its paired allele is dominant.

With eye color, the brown eye allele is dominant to the blue eye allele. This means that a child with a blue allele from their mom and a brown allele from their dad will end up with brown eyes. But a child with two blue alleles will display the blue eye phenotype.

Question 12

an individual who is Aa is

Answer 12

heterozygous (two different alleles)

Question 13

what is a gene

Answer 13

Genes are sections of DNA that contribute to certain traits, characteristics or functions. Genes code for proteins or parts of proteins that influence things like the immune system, skin pigmentation, hormone production, and eye color. Genes are transcribed into RNA molecules, which are then translated into proteins. Segments of DNA demarcated as genes consist of both coding and non-coding regions. Coding regions, also called exons, are the sections transcribed into eventual protein. Non-coding regions, or introns, are not transcribed, but are thought to fulfill numerous other functions such as regulation of transcription. Humans have approximately 20,000 protein-coding genes, which represent less than 2% of the total genome.

Question 14

alternative splicing

Answer 14

The classical understanding of a gene placed it as the singular unit of inheritance, with a rigid structure of “one gene-one RNA-one protein”. New findings in the modern era of genomics, however, have realigned this paradigm. For example, it is now known that genes are capable of producing more than one RNA molecule, through a process known as alternative splicing.

Alternative splicing is a cellular process in which exons from the same gene are joined in different combinations, leading to different, but related, mRNA transcripts. These mRNAs can be translated to produce different proteins with distinct structures and functions — all from a single gene

Question 15

phenotype

Answer 15

how a trait is expressed in an organism

Question 16

what are loci

Answer 16

There are multiple versions of a base that can be found at any given genomic location, or loci. Allele is the term used to describe these different versions of a gene. For example, at one particular loci, two alleles may exist, one that codes for a cytosine base and one that codes for a thymine base. Humans inherit two copies of their genome – one from each parent. As such, we are known as diploid organisms.

Question 17

erythromelalgia

Answer 17

recurrent sensation of warmth and pain (too much sodium is going through a specific ion channel so the pain receptors are working overtime)

Question 18

gain of function mutation

Answer 18

A mutation that confers new or enhanced activity on a protein

Question 19

Loss-of-function mutations

Answer 19

more common, result in reduced or abolished protein function

Question 20

deleterious allele

Answer 20

For example, the gene that causes sickle cell anemia is deleterious if you carry two copies of it. But if you only carry one copy of it and live in a place where malaria is common, the gene is advantageous because it confers resistance to malaria.

Question 21

inbreeding depression

Answer 21

The accumulation of homozygous deleterious
recessive alleles in a population causes inbreeding depression, impairing the
ability of individuals to survive and reproduce