Inheritance

Question 1

Who created the concept of inheritance?

Answer 1

Gregor Mendel

Question 2

What did Gregor Mendel study?

Answer 2

Peas

Question 3

What did Gregor Mendel find in his studies?

Answer 3

That some traits are recessive and some are dominant

Question 4

Define phenotype

Answer 4

A physical characteristic of an organism, which is determined by the organisms genotype as well as the environment.

Question 5

Define genotype

Answer 5

A set of alleles possed for a particular gene or genes of an organism

Question 6

When doing testing for inheritance what is good features and factors to have of the trial?

Answer 6

• Breed often and have lots of offspring
• Observable phenotypes
• Short lifecycle
• Produce statistically significant results

Question 7

Define homozygous

Answer 7

If an individual contains two alleles that are coding for the same dominant or recessive trait (also known as pure breeding)

Question 8

Define heterzygous

Answer 8

Individuals with one allele coding for the recessive trait and one allele coding for the dominant trait. Also known as hybrids)

Question 9

What is complete dominance?

Answer 9

When a phenotype trait is completely dominant over the other trait

Question 10

Why does complete dominance occur?

Answer 10

Enough protein being produced from a single allele for a particular phenotype, or two alleles coding for a dominant trait.

Question 11

Define Dominant Trait

Answer 11

A trait that is expressed with a heterozygous genotype. Only a single copy of the allele is required for the traits expression

Question 12

Deine Recessive Trait

Answer 12

Refers to a trait that is only expressed in a homozygous genotype.

Question 13

Define Pure Breeding

Answer 13

An organism that contains two exact alleles and when crossed with it self or others like t, it will always produce an offspring with a phenotype the same.

Question 14

Define Codominance

Answer 14

When both alleles in the genotype are expressed equally in the phenotype, resulting in both traits being exhibited

Question 15

Define Incomplete Dominance

Answer 15

Two pure breeding parents that can have an offspring that have a blend of their parental phenotype

Question 16

Define Dihybrid crosses

Answer 16

When two genes are crossed they can either be on the same chromosome or different

Question 17

What will the test cross for a heterozygous individual result in reagrds to the ratio

Answer 17

1:1:1:1

Question 18

When are alleles considered to be linked?

Answer 18

When they are on the same chromosome

Question 19

Define alleles

Answer 19

Alternative forms of a gene

Question 20

Define Chromosomes

Answer 20

Strand of DNA encoded of genes

Question 21

Define Autosomal Recessive

Answer 21

A genetic condition that appears only in individuals who have recieved two copies of an autosomal gene, one from each parent

Question 22

Define Autosomal Dominant

Answer 22

Requires only one of the affected trait in the genotype for it to be expressed in the phenotype

Question 23

Define a gene

Answer 23

Short section of DNA that codes for a specific protein

Question 24

Where are genes located?

Answer 24

Chromosomes

Question 25

what do alleles code for?

Answer 25

traits

Question 26

Define chromosome

Answer 26

One long DNA molecule surrounded by many histone proteins

Question 27

Why are DNA supercoiled chromatin?

Answer 27

In order to fit within a cell

Question 28

Why is the centromere important?

Answer 28

Helps anchor the chromosome to spindle fibres during the cell division process of miitosis and meiosis.

Question 29

Define autosomal chromosomes

Answer 29

Form homologous pairs that do not differ between sexes

Question 30

Define sex chromosomes

Answer 30

Determine the sex of an organism

Question 31

Define somatic cells

Answer 31

They are body cells

Question 32

What are egg or sperm cells?

Answer 32

Haploid

Question 33

What are somatic cells?

Answer 33

Diploidd

Question 34

Define hemizygous

Answer 34

One gene is deleted

Question 35

What are lethal genotypes

Answer 35

In some cases homozygous genotypes can be lethal,
will produce a ratio of 2:1
will be double dominant

Question 36

Define pedigree

Answer 36

A family tree that shows the frequency and occurence of a particular phenotype over many generations

Question 37

what is polygenetic inheritance

Answer 37

Chracteristic is controlled by more than one gene

Question 38

What variation are polygenic inhertiance

Answer 38

Continous varitation

Question 39

Discontinous Variation

Answer 39

When members of a population can be grouped into a few discrete and non-overlapping classes of a trait

Question 40

what is discontinous variation caused by?

Answer 40

A single gene monogenic

Question 41

Continous variation

Answer 41

characteristics which exhibit a continous range of phenotypes across a population

Question 42

what is continous variation caused by?

Answer 42

polygenes

Question 43

What are charactersitics of an autosomal dominant pedigree?

Answer 43

• Both males and females can equally be affected
• No gender bias
• everyone will have an effected parent

Question 44

What are charactersitics of an autosomal recessive pedigree?

Answer 44

• both males and females will be equally affected

- can skip a generation

Question 45

Pedigree: X linked dominant

Answer 45

An affected male will pass the trait to all his daughters

Affected person has at least one affected parent

Question 46

X linked recessive pedigree

Answer 46

Father of affected female must show trait