17.1 - Laying Foundations: Peas, Patterns, and Probabilities.

Question 1

Selective breeding

Answer 1

choosing stock because of its physical, behavioral, or functional characteristics.

Question 2

Inheritable trait

Answer 2

a characteristic that is determined by genes, not the environment; a trait that is capable of being passed from parent to offspring.

Question 3

Pangenesis

Answer 3

Aristotle proposed a theory of inheritance called pangenesis.

• theory: egg and sperm consist of particles, called pangenes, from all parts of the body. When the egg is fertilized, the pangenes develop into the parts of the body from which they were made.

Question 4

True breeding

Answer 4

organisms that produce offspring that express the same trait generation after generation; organisms are homozygous for a trait.

Question 5

P generation

Answer 5

The true breeding plant. The first set of parents; parents of the F1 generation.

Question 6

F1 generation

Answer 6

Offspring of the P1 generation: F stands for filial meaning brothers and sisters.

Question 7

F2 generation

Answer 7

Offspring produced as a result of individuals of the F1 generation mating with other individuals of the F1 generation.

Question 8

Monohybrid cross

Answer 8

a cross of two individuals, each of which is heterozygous for one trait.

Question 9

Genotype

Answer 9

What the genes say; two symbols that indicate which alleles the individuals has for a particular trait (e.g., Tt)

Question 10

Phenotype

Answer 10

the observable characteristic of the organism. ex.) height

Question 11

Dominant

Answer 11

if two alleles are present, the allele that is expressed is the dominant one (e.g., if an individual has both tall and short alleles, but is tall, then tall is dominant over short)

Question 12

Recessive

Answer 12

if two alleles are present, the allele that is hidden is recessive

Question 13

Homozygous

Answer 13

a genotype where both alleles are the same (e.g. ,TT is homozygous dominant, tt is homozygous recessive)

Question 14

Heterozygous

Answer 14

a genotype where the alleles are different (e.g.,Tt)

Question 15

The law of segregation

Answer 15

the two genes that an organism has for each trait are separated during meiosis so that only one gene can enter a gamete; explains why body cells are diploid, but gametes are haploid.

• a parent gives ONE allele for a gene to each gamete.

Question 16

Sickle cell anemia

Answer 16

an autosomal recessive disease that causes sickle-shaped red blood cells to form, which get caught in blood vessels, stopping blood flow to tissues

Question 17

What did Gregor Mendel discover?

Question 18

Why did Mendel choose the garden pea?

Question 19

Allele

Answer 19

The different forms of each gene.

Question 20

Incomplete dominance

Answer 20

some genes have two alleles - neither of which are dominant; mixture of both alleles.

• like mixing paint.

black x white = grey

• in between trait
• no lowercase letters.
• uppercase letter with a subscript.

Question 21

Co-dominance

Answer 21

a situation in which BOTH alleles are fully expressed.

• observable phenotype
• no dominant/recessive

Question 22

Dihybrid

Question 23

Law of independent assortment

Question 24

Genotypes for blood type A

Answer 24

I^A I^A or I^A I^i

Question 25

Genotypes for blood type O

Answer 25

ii

Question 26

Genotype for blood type B

Answer 26

I^B I^B, I^B I^i

Question 27

Genotype for blood type AB

Answer 27

I^A I^B