Chapter 1: An Introduction to Genetics

Question 1

How many genes are in the human genome?

Answer 1

• ~25,000

Question 2

What are the two processes via gene expression?

Answer 2

• transcription of DNA and translation of RNA

Question 3

What is genetics?

Answer 3

the science of heredity and variation

Question 4

What is heredity?

Answer 4

• transmission of traits from one generation to another

Question 5

What is a trait?

Answer 5

• a detectable phenotypic variation of an inherited character
  ( blue vs brown eye colour)

Question 6

What is a character?

Answer 6

• observable phenotypic attribute of an organism

Question 7

Explain what a chromosome is / purpose.

L> composition?

Answer 7

• the organization of genes
• they vary in number and in size
• help to identify gene loci
• thread like structures in the nuclei carry hereditary
  L> composed of protein and nucleic acids.

Question 8

Haploid??

Answer 8

• one copy of genetic material subdivided into chromosomes
  L> half the number of chromosomes (N)
  L>haploid cells contain only one complete set of chromosomes
  L> gametes and germ cells
  L> products of meiosis
  L> non homologous chromosomes
  (N)

Question 9

Diploid??

Answer 9

• two copies of genetic material subdivided into chromosomes
  L> three pairs of homologous chromosomes
  L> contain two complete sets of chromosomes (n)
  L> products of mitosis
  (2N)
• somatic cells etc

Question 10

Chromosomes are arranged in what kind of fashion in humans?

Answer 10

LINEAR

Question 11

Karyotype?

Answer 11

• linear arrangement of chromosomes from largest to smallest!

Question 12

Loci?

Answer 12

• where genes are located on the chromosome

Question 13

mu??

Answer 13

map unit= genetic distance…..

Question 14

By looking at mu of two genes …if they are close to each other what can we establish?

Answer 14

• that they may be linked!

Question 15

Genotype?

Answer 15

Allelic composition of one or more limited number of genes under investigation
L> specific genetic constitution of an organism

Question 16

Phenotype?

Answer 16

• observble expression of genetic make up…manifestation of genotype
  L> genetically controlled observable features

Question 17

Allele?

L> diploid??

Answer 17

• different versions of a gene

L> two alleles for one gene in a diploid individual

Question 18

Homozygous?

Answer 18

• identical alleles for a gene

Question 19

Heterozygous?

Answer 19

• different alleles for a gene

diff gene in each gamete

Question 20

Mendel’s laws of inheritance go! (3)

Answer 20

1. Law of Segregation
2. Law of Independent Assortment
3. Law of Dominance

Question 21

Mendel’s laws of inheritance :

1. Law of Segregation? ( a lot)

Answer 21

1. two members of a gene pair (alleles) segregate (separate) from each other during the formation of gametes in meiosis. As a result half the gametes carry on allele the other half have the other allele. AKA Each gamete carries only a single allele of each gene…the progeny are produced by the random combination of gametes from the two parents.

Question 22

When does segregation occur?

Answer 22

-members of a pair of alleles segregate during meiosis and that each offspring receives only one allele….therefore it parallels the separation of homologous pairs of chromosomes at anaphase 1 in meiosis.

Question 23

Mendel’s laws of inheritance:

2. Law of Independent Assortment?

Answer 23

the pairs of alleles for genes on different chromosomes segregate independently in the formation of gametes.
L> during meiosis 1
L>independent of each pair of homologous chromosomes…before separation in meiosis 1.

Question 24

Mendel’s laws of inheritance

3. Law of dominance?

Answer 24

the dominant form of a trait shows up in an individual that is heterozygous ( one dominant factor and one recessive factor )

Question 25

Mendel's laws of inheritance | - Unit factors are said to be in ___.

Answer 25

- pairs | L> one paternal and one maternal homologue

Question 26

What three things account for genetic variation?

Answer 26

1. mutation 2. recombination 3. selection

Question 27

Genetic Variation: | 1. Mutation?

Answer 27

- change in the DNA or chromosome ( i.e. deletion, brewing of chromosome, inversion etc)

Question 28

Genetic Variation: | 2. Recombination ?

Answer 28

- exchange of genetic material

Question 29

Genetic Variation: | 3. Selection?

Answer 29

- Favouring a combination of genes in a given environment ....product of selection = the next generation ( we the current generation don't matter sob)

Question 30

Haploid?

Answer 30

- 1 copy go each chromosome (N) | - gametes

Question 31

Diploid ?

Answer 31

- 2 copies of each chromosome (2N) | L> result from fusion of 2 games = zygote

Question 32

Homologous Chromosomes?

Answer 32

- chromosomes that contain the same genes and pair during meiosis - each member of a pair is a HOMOLOG

Question 33

Non-homologous chromosome?

Answer 33

- chromosomes that do not contain similar genes | - do not pair during meiosis

Question 34

exception to non homologous chromosomes not pairing in meiosis?

Answer 34

X and Y

Question 35

What are the two types of Chromosomes ?

Answer 35

- autosomes ( do not determine sex) | - sex chromosomes ( xx and xy )

Question 36

What is at the end of the chromosome that is responsible for aging via shortening of it?

Answer 36

- teleomere L> repeating regions of dan ...non coding gene.... L> Y is telecentric (only one in us)

Question 37

``` Chromosome Morphology? L> Meta L> Sub L> Acro L> Telo ```

Answer 37

- distinguishable via the placement of the centromere L> 2 arms are equal L> 2 arms are unequal L> stalk, satellite L> centromere is just at the end of the chromosome .....( no division of arms)

Question 38

Who created the first recombinant DNA molecule?

Answer 38

- Paul Berg

Question 39

Who cloned the first recombinant DNA molecule?

Answer 39

- Boyer and Cohen

Question 40

Who developed polymerase chain reaction?

Answer 40

- Kary Mullis | L> out of cell way to synthesize genes

Question 41

Genomis = what?

Answer 41

- determination of complete genomic DNA sequences

Question 42

Who created the artificial genome and inserted it into a prokaryotic cell?

Answer 42

- Craig Venter

Question 43

Plasmid?

Answer 43

- small DNA molecule that is separate from the chromosomal DNA and independently replicates L> insert recombinant DNA into bacteria and it will integrate it ......

Question 44

Transmission genetics?

Answer 44

classical genetics

Question 45

molecular genetics?

Answer 45

molecular structure and function of genes

Question 46

population genetics?

Answer 46

study of heredity in groups of individuals for traits that are determined by one or only a few genes

Question 47

Quantitative genetics?

Answer 47

study of heredity in groups of individuals but the traits are determined by many genes simultaneously

Question 48

What is recombinant DNA technology? | L> significant?

Answer 48

- procedures that allow molecular biologists to splice DNA fragment from one organism into DNA from another organism to clone the new recombinant DNA L> yes...medically: produces antibiotics hormones and other agents like clotting factors and insulin.