Chapter 11 - Genetics

Question 0

How are physical traits inherited?

Answer 0

Physical traits are inherited as chromosomes.

Question 1

Gregor Mendel

Answer 1

(1822-1884). Responsible for the laws governing inheritance of traits. The “father of genetics” studied inheritance in 28,000 pea plants.

Question 2

What is a trait?

Answer 2

A trait is a specific characteristic inherited from parent.

Question 3

What is heredity?

Answer 3

Heredity is the passing of traits from parents to offspring.

Question 4

What is genetics?

Answer 4

Genetics is the study of heredity.

Question 5

what is an allele?

Answer 5

an allele is the form of a gene. there is two.
Dominant alleles are alleles that only one of them are enough to exhibit the trait.
Recessive alleles are alleles that need to be present 100% to exhibit the trait.

Question 6

Peas

Answer 6

• self pollinate.
• can be artificially cross pollinated (what Mendel did).
• produce lots of offspring.

Question 7

Types of fertilization

Answer 7

Self Fertilization can occur in the same flower.

Cross Fertilization can occur between flowers.

Question 8

The larger the sample…

Answer 8

the more nearly the results approximate to the ratio.

Question 9

Theoretical Ratio

Answer 9

expected ratio of an offspring exhibiting the traits. E.X.: 3:1

Question 10

Generations

Answer 10

Parental (P1) Generation: parental (first) generation in a breeding experiment.
F1 Generation: offspring of the parental generation.
F2 Generation: offspring of the F1 generation.

Question 11

The cross of two pure (homozygous) organisms results in…

Answer 11

All hybrids (heterozygous).

Question 12

The cross of two hybrids results in…

Answer 12

One homozygous dominant, one homozygous recessive and two heterozygous. (pheno. ratio 3:1).

Question 13

if one dominant allele is present…

Answer 13

exhibit the dominant trait.

Question 14

Law of Dominance

Answer 14

If a dominant allele is present, it will exhibit the dominant trait.

Question 15

Law of Segregation

Answer 15

During the formation of gametes, the alleles separate from each other.

Question 16

Offspring of crosses between parents with different traits are called…

Answer 16

hybrids

Question 17

Different forms of a gene are called

Answer 17

Alleles

Question 18

The joining of male and female reproductive cells during sexual reproduction is known as…

Answer 18

fertilization.

Question 19

A specific physical characteristic, such as seed color or plant height, of an individual is called a(n)…

Answer 19

trait.

Question 20

The process in which alleles separate from each other during meiosis so that each gamete carries only a single copy of each gene is called…

Answer 20

segregation.

Question 21

a monohybrid cross is…

Answer 21

a cross involving a single trait.

Question 22

a dihybrid cross is…

Answer 22

a cross involving two traits.

Question 23

a punnett square is used to…

Answer 23

to help solve genetics problems.

Question 24

the genotype is...

Answer 24

the genetic makeup.

Question 25

the phenotype is...

Answer 25

the physical trait that depends on the genotype.

Question 26

a homozygous genotype is...

Answer 26

a genotype composed by both dominant or both recessive alleles.

Question 27

a heterozygous genotype is...

Answer 27

a genotype composed by one dominant and one recessive allele. Also called hybrid.

Question 28

the test cross is...

Answer 28

the crossing of a pure (can be dominant or recessive) and a hybrid. it results in a 1:1 phenotypic ratio.

Question 29

What are is the phenotype based on?

Answer 29

The Genotype.

Question 30

each trait is based on...

Answer 30

two genes, one from the mother and one from the father.

Question 31

Law of Independent Assortment

Answer 31

Alleles for different traits are distributed to sex cells independently of one another.

Question 32

dihybrid cross

Answer 32

the tracking of the inheritance of two traits.

Question 33

formula for the dihybrid cross

Answer 33

2^n where n is the # of heterozygotes.

Question 34

what would be the offspring of this cross? TT x tt Tall x Short

Answer 34

All of them would be hybrid

Question 35

what would be the offspring of the following cross? Tt x Tt Tall x Tall

Answer 35

75% tall (TT and Tt) and 25% short (tt).

Question 36

what is incomplete dominance?

Answer 36

There is no dominant allele, so they both combine and exhibit a mixed trait. (Red + White = Pink).

Question 37

what is codominance?

Answer 37

Both traits are exhibited at the same time. (Example: blood type. there is 4 types (A, B, AB and O) and there are 3 alleles (IA, IB and i). IA and IB are both dominant at the same time).