GENETICS

Question 1

study of heredity

Answer 1

Genetics

Question 2

set the framework for genetics long before chromosomes or genes had been identified, at a time when meiosis was not well understood. He
selected a simple biological system and conducted methodical, quantitative analyses using large sample
sizes.

Answer 2

Johann Gregor Mendel

Question 3

Mendel‘s seminal work was accomplished using the garden pea, _________ , to study inheritance. This species naturally selffertilizes, meaning that pollen encounters ova within the same flower.

Answer 3

Pisumsativum

Question 4

mating two true-breeding individuals
that have different traits. (Pea can self fertilized)

Answer 4

Hybridizations

Question 5

• P - Parental generation - are all parents are color white?
• F1 Generations - Filial 1 - produce 705 white pea plants
• F2 Generations - Filial 2 - 224 are violet peas
• etc.

Question 6

• reduction division; reduce parents by dividing haploid

Answer 6

Meiosis

Question 7

• defined as a variation in the physical appearance of a heritable characteristic.

Answer 7

Trait

Question 9

• a paired cross in which the respective
  traits of the male and female in one cross become the respective traits of the female and male in the other
  cross.

Answer 9

Reciprocal cross

Question 10

• those that are inherited unchanged in
  a hybridization.

Answer 10

Dominant traits

Question 11

• becomes latent, or disappear in the
  offspring of a hybridization.

Answer 11

Recessive traits

Question 12

• the observable traits expressed by an
  organism. (Examples: skin color, curly/wavy hair, etc.)

Answer 12

Phenotype

Question 13

• an organism‘s underlying genetic makeup, consisting of both the physically visible and the non-
  expressed alleles. (Example: behavior, ability, and other characteristics.)

Answer 13

Genotype

Question 14

are physical expressions of traits that are transmitted by alleles. Capital letters represent dominant alleles and lowercase letters represent recessive alleles. The phenotypic ratios are the ratios of visible characteristics.

Answer 14

Phenotypes

Question 16

The genotypic ratios are the ratios of gene combinations in the offspring, and these are not always distinguishable
in the phenotypes.

Question 17

• expressed unit factor

Answer 17

Dominant Allele

Question 18

• latent unit factor

Answer 18

Recessive Allele

Question 19

Mendel‘s _______ states that in a heterozygote, one trait will conceal the presence of another trait for the same characteristic. For example,
when crossing true- breeding violet-flowered plants with true-breeding white- flowered plants, all of the offspring were violet flowered, even though they all had one allele for violet and one allele for white.

Rather than both alleles contributing to a phenotype, the dominant allele will be expressed exclusively. The recessive allele will remain latent, but will be transmitted to offspring in the same manner as that by which the dominant allele is transmitted. The recessive trait will only be expressed by offspring that have two copies of this allele and these offspring will breed true when self-
crossed.

The allele for albinism, expressed here in humans, is recessive. Both of this child‘s parents carried the recessive allele.

Answer 19

law of dominance

Question 21

is a chart that allows you to easily
determine the expected percentage of different genotypes in the offspring of two parents.

Answer 21

Punnett square

Question 22

states that paired unit factors (genes) must segregate equally into gametes such that offspring have an equal likelihood of inheriting either factor.

Answer 22

Law of Segregation

Question 23

The dominant-expressing organism is crossed with an organism that is homozygous recessive for the same
characteristic.

Answer 23

Test Cross

Question 24

One of the alleles appears in the phenotype in the heterozygote, but not to the exclusion of the other, which can also be seen.

Answer 24

Incomplete Dominance

Question 25

Both alleles for the same characteristic are simultaneously expressed in the heterozygote.

Answer 25

Codominance

Question 26

Exist at the population level, such that many combinations of two alleles are observed.

Answer 26

Multiple Alleles

Question 27

Blood types: • A - negative 6% • O - negative 7% • B - positive 11% • A - positive 32 % • O - positive 40%

Question 28

Rarest blood types: • AB - negative 1% • B - negative 2 % • AB - positive 4 %

Question 29

A - Can receive only from A,O Can give to AB, A AB - Universal recipient. Can only give to AB. B - Can receive only from B, O Can only give to AB, B Blood type O - universal donor. Can receive only from blood type O

Question 30

also referred to as Hardy-Weinberg Principle, is used to compare allele frequencies in a given population over a period of time.

Answer 30

Hardy-Weinberg Equilibrium

Question 31

A population of alleles must meet five rules in order to be considered “in equilibrium”. 5 rules: 1. No gene mutations may occur and therefore allele changes do not occur. 2. There must be no migration of individuals either into or out of the population. 3. Random mating must occur, meaning individuals mate by chance. 4. No genetic drift, a chance change in allele frequency, may occur. 5. No natural selection, a change in allele frequency due to environment, may occur. Handy-Weinberg Equilibrium never occurs in nature because there is always at least one rule being violated. Handy-Weinberg Equilibrium is an ideal state that provides a baseline against which scientist measure gene evolution in a given population. The Handy-Weinberg Equilibrium can be used for any population; the population does not need to be in equilibrium.