Unit C: Genetics

Question 1

Gregor Mendel

Answer 1

➼ Mid-19th Century Austrian monk.
➼ Known as the “Father of Genetics.”
➼ Tracked and recorded characteristics in snow peas.

Question 2

First Filial Generation (F1)

Answer 2

Offspring produced by parents.

Question 3

Second Filial Generation (F2)

Answer 3

The offspring of F1.

Question 4

Gene

Answer 4

The characteristic (i.e hair colour).

Question 5

Genotype

Answer 5

Alleles that someone has in their genetic code.

Question 6

Allele

Answer 6

The different types found in the gene pool (i.e red, black, brown, and blonde hair).

Question 7

Phenotype

Answer 7

Physical expression of genetics.

Question 8

Homozygous Dominant

Answer 8

Two dominant alleles represented by a uppercase letters (AA).

Question 9

Heterozygous (Hybrid)

Answer 9

One dominant and one recessive allele represented by a single uppercase letter along with a sing lowercase letter (Aa).

Question 10

Homozygous Recessive

Answer 10

Two recessive alleles represented by two lowercase letters (aa).

Question 11

Mendel’s First Law - The Law of Segregation

Answer 11

Alleles separate randomly during gamete formation. Each gamete receives one copy of every factor.

Question 12

Autosomal

Answer 12

“Body,” chromosomes 1-22.

Question 13

Sex-Linked

Answer 13

Chromosome 23 (XX = genetic female; XY = genetic male).

Question 14

Autosomal Dominant

Answer 14

A individual exhibits a dominant phenotype when they inherit at least 1 dominant allele from one parent on chromosomes 1-22.

Question 15

Autosomal Recessive

Answer 15

A individual exhibts a recessive phenotype when they inherit 2 recessive alleles, one from each parent, on chromosomes 1-22.

Question 16

Y-Chromosomes

Answer 16

Only genetic males with XY chromosomes inherit these genes.
➼ Genetic males have a higher probability of inheriting the recessive trait due to having one X chromosome.

Question 17

Multiple Alleles

Answer 17

➼ Traits are typically controlled by multiple types of alleles.
➼ Heirarchy of Dominance
➼ Uppercase letters and superscript numbers are used to express a genotype.

Question 18

Incomplete Dominance

Answer 18

When two alleles come toegher and are equally dominant, they will produce a new phenotype.

Question 19

Co-dominance

Answer 19

Both phenotypes are fully expressed.
➼ i.e blood type (AB)

Question 20

Rh Factor

Answer 20

➼ Along with our blood there is another antigen known as the Rhesus Factor.
➼ If an individual has the Rh antigen, then they are Rh+.
➼ If an individual does not have the Rh antigen, then they are Rh-.
➼ Rh+ is dominant over Rh-.

Question 21

Mendel’s Second Law - Law of Independent Assortment

Answer 21

The two alleles for one gene assorts independently of the alleles for another gene.

Question 22

Gene Interactions

Answer 22

Genes located on one chromosome can affect the expression of other genes.

Question 23

Epistasis

Answer 23

When one gene is dependent on the presence of another.

Question 24

Sex-Linked Genes

Answer 24

➼ Genes that are traits determined by genes located on sex-chromosomes (usually the X-Chromosome).
➼ The symbols for sex-linked traits are written with a capital X and a superscript of the letter representing the allele.
➼More recessive x-linked disorders occur in males.

Question 25

Breeding Plants

Answer 25

➼ Corn is the result of selective breeding across many generations.
➼ Canola was developed as a alternative to rapeseed, a crop that is highly poisonous to animals.

Question 26

Breeding Animals

Answer 26

Breeding programs are used to breed:
➼ Leaner cows
➼ Leaner Pigs.
➼ Chicken eggs with less cholestrol.
➼ Faster, strong horses.

Question 27

Human Genetics

Answer 27

➼ Cannot do experimental breeding on humans.
➼ Too few offspring are produced to be statistically valid.
➼ Will collect family information and create a pedigree chart.

Question 28

Pedigree Chart

Answer 28

A chart that uses symbols and finds patterns of traits in a family.

Question 29

Pedigree Chart (Dominant)

Answer 29

➼ When observing a pedigree chart, autosomal dominant disorders are in every generation (at least in one child).
➼ If one child has the recessive phenotype, this means the parents are heterozygous for the dominant trait.

Question 30

Pedigree Chart (Recessive)

Answer 30

➼ When building a pedigree chart, autosomal recessive traits are seen less than dominant traits.
➼ Usually seen every couple of generations (often will skip one or two).
➼ Often only one of the offspring will inherit the trait.

Question 31

Sex-Linked Traits

Answer 31

➼ More genetic males will express the trait than genetic females.
➼ Genetic females perchance might be carriers but will not express the trait - will be passed on.

Question 32

Linked Genes and Crossover

Answer 32

➼ Genes that are found on the same chromosome.
➼ Since they are found on the same chromosome, these traits are often found together.

Question 33

Chromosome Mapping

Answer 33

➼ Recombination frequency - the precentage of times that a crossover occurred as the parent gametes were formed.
➼ Percentage = map unit. ➼ Farther apart the genes = larger the map unit/percentage.