Chapter 10

Question 0

Gene locus

Answer 0

Location of an allele on the chromosomes in a homologous pair

Question 1

Allele

Answer 1

Each letter in a gene

Question 2

Genetic linkage

Answer 2

Tendency of genes closer together on same chromosome to be inherited together

Question 3

Sex linked

Answer 3

Often cause a recessive trait, passed on by carriers (females, do not express trait but may pass it on to offspring), usually on X chromosome, more common in males than females.

Question 4

True/ Pure breeding

Answer 4

A plant that produces identical, heterozygous offspring when it self,-fertilizes

Question 5

Monohybrid crosses

Answer 5

Breed 2 plants that only differ in 1 trait. If cross 2 heterozygous individuals. Genotype ratio 1:2:1 phenotype ratio 3:1

Question 6

Dihybrid cross

Answer 6

The crossing of plants that differed in 2 characteristics. If crossing 2 heterozygous individuals, genotype ratio differs, phenotype ratio is always 9:3:3:1

Question 7

When are test crosses used? What do they tell you?

Answer 7

To determine the genotype of the dominant trait, and they tell you the odds that the offspring has a certain genotype

Question 8

Independent assortment

Answer 8

During gamete formation in F2 cross, a particular allele for one character can be paired with either allele of another character, usually happens in dihybrid crosses

Question 9

Principal of segregation of alleles

Answer 9

2 alleles of a trait separate when a parent forms gametes, each gamete only gets 1 allele (one version of the gene)

Question 10

Chromosome theory of inheritance

Answer 10

Genes are located on chromosomes (chromosomes got into gametes > offspring inherits these genes), behavior of chromosomes in meiosis and fertilization explains inheritance patterns.
•Independent assortment: alleles of a gene sort into gametes independently of allele pair
•segregation of alleles: each gamete gets 1 allele from each allele pair)

Question 11

Complete dominance (simple dominant/recessive)

Answer 11

F1 and F2 offspring resemble one parent or the other, dominant trait overshadows recessive trait (normal pattern)

Question 12

Incomplete dominance

Answer 12

F1 offspring has Phenotype different from either parent, parental traits re-emerge in F2. Ex: red flower RR and white flower WW = RW pink flower (in the middle)

Question 13

Co dominance

Answer 13

F1 offspring fully expresses both alleles (both parents phenotypes) Ex: AB bloodtype

Question 14

Multiple alleles

Answer 14

Gene has 3 or more alleles (not just 2) ex. Bloodtype (A, B, AB, O)

Question 15

Polygenic inheritance

Answer 15

Single trait based on several genes, ex. Height, skin color, more genes > more. Allele combos > bigger range of phenotypes

Question 16

How do environmental effects interact with genes to influence traits?

Answer 16

Nature vs. nurture, traits depend on genes and environment