M1 L1: Intro to Genetics

Question 1

How did we know humans had an understanding of genetics?

Answer 1

They knew about domestication and selective breeding to get certain traits in plants/animals

Question 2

What was Aristotle’s view on genetics? Did it include epigenesis?

Answer 2

Semen has a vital heat that cooks menstrual blood into a fetus. Yes epigenesis

Question 3

What is epigenesis? Who came up with the idea?

Answer 3

Fetus grows de novo in utero. It does not start as a tiny, fully formed human with proper limbs. William Harvey

Question 4

What was the Hippocratic School of Medicine theory of genetics? Did it include epigenesis?

Answer 4

Believed humors from male body went into semen. The humors could be diseased or normal, and that influenced the development of the fetus. I don’t think it follows epigenesis?

Question 5

What’s the Homunculus theory of heredity? Does it include epigenesis?

Answer 5

Semen includes a tiny fully formed human. Grows after implanting. No epigenesis

Question 6

What’s the Ovist theory of heredity? Does it include epigenesis?

Answer 6

Egg contains fully formed human. Grows when stimulated by semen. No epigenesis

Question 7

What’s the germ plasm theory? Who came up with it?

Answer 7

Ovaries and testes each have a full set of genetic info, egg and sperm each deliver half to offspring. August Weissman

Question 8

What’s nuclein? Who proposed it was the genetic material?

Answer 8

Nucleic acid and peoteins. Edmund Beecher Wilson

Question 9

Who discovered the first genetic disorder? What was it?

Answer 9

Archibald Garrod. Alkaptonuria, black urine disease

Question 10

What 4 ideas led us to better theories of heredity?

Answer 10

1) Schleiden and Schwann cell theory: all life is made of cells; all cells come from other cells

2) louis pasteur refuted spontaneous generation: living matter can’t arise from nonliving matter

3) refuted fixity of species: species are not fixed; they have changed over time

4) natural selection: 3 premises, 3 conclusions for how species change over time

Question 11

3 premises of NS

Answer 11

1) species have genetic variation, at least some is heritable

2) some heritable variation affects rates of survival and reproduction

3) species overproduce, produce more offspring than environment can support

Question 12

3 conclusions of NS

Answer 12

1) there will be a struggle for existence among offspring

2) individuals with traits better fit for the environment will have more survival and reproductive success

3) adaptive traits will accumulate and the population will change through time

Question 13

What’s blending inheritance? Who believed in it?

Answer 13

Offspring are the average value of the parents. Darwin

Question 14

What’s the problem with blending inheritance? Who discovered this?

Answer 14

It’s incompatible with NS because advantageous traits will get diluted and never become fixed in populations. Fleeming Jenkin

Question 15

What does diploid mean?

Answer 15

organism has 2 full sets of genes (maternal and paternal)

Question 16

what is a gene

Answer 16

the functional unit of heredity

Question 17

what are alleles

Answer 17

different variations of a gene

Question 18

what’s haploid?

Answer 18

organism has 1 copy of each gene

Question 19

what’s the chromosomal theory of inheritance? who discovered it?

Answer 19

Genes are on chromosomes. Sutton and Boveri

Question 20

what’s the universality of mendelian inheritance? Who supported it? What debate did it start?

Answer 20

All inheritance follows Mendel’s fundamental rules. Inheritance is particulate. William Bateson. Biometricians vs. Mendelians on continuous traits

Question 21

Biometrician argument? Who showed that Mendelian inheritance can explain continuous traits?

Answer 21

Continuous traits can’t be explained by Mendelian inheritance. Herman Nilsson-Ehle, Edward East showed it’s possible if the trait is governed by multiple genes

Question 22

Who confirmed the chromosomal theory of inheritance and how?

Answer 22

Thomas Hunt. Red eye WT flies vs white eye mutant flies.

Question 23

source of all genetic variation?

Answer 23

mutations

Question 24

why did people think proteins were the hereditary material, not DNA

Answer 24

proteins are made of 20 different animo acids which would allow for greater complexity. DNA is made of 4 different nitrogenous bases which shouldn’t result in as much complexity

Question 25

3 structural differences between DNA and RNA

Answer 25

1) DNA is double stranded, RNA is single

2) DNA has thymine, RNA has uracil

3) DNA has deoxyribose, RNA has ribose

Question 26

What bonds are in DNA

Answer 26

1) covalent phosphodiester bonds in the backbone (between phosphate and sugar)

2) hydrogen bonds between nitrogenous bases

Question 27

components of a nucleotide

Answer 27

1) Nitrogenous base

2) ribose or deoxyribose

3) phosphate

Question 28

What is the central dogma

Answer 28

DNA gets transcribed into RNA, RNA gets translated into proteins

Question 29

How does a change in a nucleotide cause sickle cell disease?

Answer 29

Change nucleotide causes a change in RNA –> change in animo acid –> change in protein shape –> a change in protein function –> sickle cell disease

Question 30

Why do we use model organisms like mice, bacteria, yeast, and flies?

Answer 30

1) fast generation
2) easy to manipulate

Question 31

6 pieces of evidence of LUCA

Answer 31

1) all orgs use universal genetic code
2) all orgs use central dogma
3) all orgs composed of common chemical parts (DNA, RNA, amino acids) and structures (membrane bound organelles)
4) all orgs extract energy from environment
5) all orgs have homologous genes from a LUCA
6) all organisms evolve through gradual changes in genetic info

Question 32

Who came up with the 3 domain model

Answer 32

carl woese

Question 33

what is a chromosome

Answer 33

a structure in cells that encode the genetic material of the organism. made of DNA and proteins

Question 34

2 key differences between meiosis and mitosis

Answer 34

1) mitosis makes 2 identical diploid daughter cells, meiosis makes 4 different haploid daughter cells

2) mitosis has one equational division, meiosis has one reductional division then one equational division

Question 35

what is a mutation

Answer 35

any heritable change in DNA

Question 36

what is base complementarity? how does it relate to DNA replication?

Answer 36

A and T or U always pair, and C and G always pair. in DNA replication, if you know one strand, you can make the other strand because it must complement the original

Question 37

what’s the role of tRNA?

Answer 37

They translate RNA into proteins by bringing the correct amino acids to the ribosomes

Question 38

Describe gel electrophoresis. What does it assay?

Answer 38

there’s a gel placed in a buffer solution. samples of DNA are pipetted into wells near the negative electrode side of the gel. when the apparatus is turned on, the DNA is pulled to the positive side of the gel because phosphate groups make DNA negatively charged. the distance the strands traveled indicates their size. shorter ones travel farther than longer ones.