Genetics

Question 1

Who is Gregor Mendel

Answer 1

Austrian monk who used pea plants to learn about genetics.

Question 2

Gregor Mendel’s 3 Laws of Inheritance

Answer 2

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

Question 3

Mendel’s Experiments

Answer 3

1. Had control over breeding
2. Used only Purebreed plants
3. Observed “either-or” traits

Question 4

A cross

Answer 4

Mating of 2 organisms
F1: First Generation
P: Parental Generation
F2: Second Generation

Question 5

Dominant Allele

Answer 5

Allele will always have that trait expressed (seen)

Question 6

Recessive Allele

Answer 6

Allele will only have that trait expressed when the dominant allele is not present

Question 7

Significance of Alleles

Answer 7

-Alleles have assigned letters
-Uppercase=Dominant
-Lowercase=Recessive
-Each individual has 2 Alleles (one from each parent)

-Homozygous: 2 of the same alleles (FF or ff)
-Homozygous: 2 different alleles (Ff)

Question 8

Genotype

Answer 8

The actual alleles Inherited (FF, Ff, ff)

Question 9

Phenotype

Answer 9

The physical characteristics or traits of an organism (freckles on face)

Question 10

Gene expression

Answer 10

can be affected by the enviroment

Question 11

Law of Dominance

Answer 11

a dominant (or strong Allele) will exxpress itself over a recessive (weak Allele)

Question 12

Law of Segregation

Answer 12

When chromosomes separate in meiosis, each gamete (egg or sperm) will recieve only one chromosome from each pair

Question 13

Law of Independent Assortment

Answer 13

-The Assortment of chromosomes for one trait doesn’t affect the assortment of chromsomes for another trait

-Therefore any combination of maternal and paternal chromosomes could be passed on because homologous chromosomes line up randomly during metaphase

Question 14

Punnett Square

Answer 14

A diagram that shows the probability of inheriting traits from parents with certain genes

Question 15

Monohybrid Cross

Answer 15

A cross between two organisms looking at one trait

Question 16

DNA

Answer 16

-Deoxyribo Nucleic Acid
-Phosphate
-Sugar (deoxyribose)
-Nitrogen Base
-Double Helix

Question 17

Organic Compounds

Answer 17

made of monomers

Question 18

Nucleotides

Answer 18

Monomers of DNA

Question 19

DNA Nucleotides (stand for)

Answer 19

G=Guanine
A=Adenine
C=Cytosine
T=Thymine

Question 20

Job of DNA code

Answer 20

The molecular Bases (G, A, C, T) determine an organism’s DNA which codes for making proteins that works in the organism’s cells/bodies to determine their traits

Question 21

Exceptions to Mendel’s Laws

Answer 21

Some alleles are neither dominant or recessive, and many traits are controlled by multiple alleles or multiple genes

Question 22

Incomplete Dominance

Answer 22

-The heterozygous phenotype is somewhere between the two homologous phenotypes

-Neither Allele is completely dominant or recessive

-Ex: red and white flowers make pink flowers

Question 23

Codominance

Answer 23

-Both traits are fully and seperately expressed

-Ex: red and white flowers make red and white speckled flowers

-Ex: blood type (AB blood type is fully A and fully B)

-Blood type is also an example of multiple alleles

Question 24

Blood Type

Answer 24

-An example of codominance and multiple alleles

-Codominance: Blood type AB is fully A and fully B

-Multiple alleles: A Allele, B Allele, and I allele

Question 25

Blood type Phenotype –> Genotype

Answer 25

-AB= IA IB
-A= IA IA, IA i
-B= IB IB, IB i
-O= ii

Question 26

Multiple Alleles

Answer 26

-Having more than 2 Alleles for one gene
-Ex: Alleles for blood type

Question 27

Polygenic Inheritance

Answer 27

-A trait produced by two or more genes
-Usually shows a range in phenotype
-Ex: Skin color, Eye color, Height, Personality

Question 28

Epistasis

Answer 28

-When one gene overshadows all others
-Ex: Laborador Retriever fur colors, eye color, Albinism

Question 29

Linked Genes

Answer 29

-Genes that are physically located on the same chromosome will be inherit together

-Ex: Blond Hair and Blue Eye, Red Hair and Freckles, Large Ears and Broad Nose

-Linked genes can only be: seperated or broken apart during crossing-over

Question 30

Sex-Linked Traits (X chromosome)

Answer 30

-Contains many genes that affect many traits

-Linked to more than 100 genetic disorders

-Genes on the X chromosome are X-Linked

Question 31

Sex-Linked Traits (Y chromosome)

Answer 31

-Carries few genes/determines if offspring is male

Question 32

Sex-Linked Traits (definition)

Answer 32

-genes on sex chromosomes (X or Y)

-Females inherit gene as normal and principle of Dominance applies

-Males inherit the gene on the X, but not the Y.

-Because males have only one X, they express the trait whether it is dominant or recessive

-Ex: Color Blindness (Xb) Normal vision (XB)

Question 33

mRNA

Answer 33

-Copies DNA’s code (instructions)
-Carries copy to the ribosomes (make proteins)

Question 34

tRNA

Answer 34

-Carries Amino Acids to the ribosome and mRNA

Question 35

Ribosomal RNA (rRNA)

Answer 35

-Makes up the ribsome

Question 36

Transcription

Answer 36

-Purpose: Carry a copy of DNA’s code for a protein out of the nucleus

-Location: Nucleus
-Starts with: DNA
-Ends with: RNA
-Gene for a protein is copied
-Copy=mRNA
-mRNA will leave the nucleus to go to the ribosome

-3 base pairs=1 codon
-1 codon=1 Amino acid

Question 37

Codon

Answer 37

a set of 3 nucleotides on the mRNA

Question 38

Anticodon

Answer 38

“complementary” 3 nucleotides on tRNA

Question 39

Translation

Answer 39

-Interpreting the RNA message into a protein

-Purpose: Read the code carried on the mRNA to make a protein

-Location: Ribosome
-Starts with: mRNA (with tRNA)
-Ends with: protein
-Protein is also called a polypeptide
-Transfer RNA (tRNA) carries amino acids from the cytoplasm to the ribosome

-mRNA carrying DNA instructions and tRNA carrying amino acids meet in the ribosomes

-Amino acids are joined together