Inheritance and Mendelian Genetics

Question 1

MENDEL’S LAWS

Answer 1

1. Law of Segregation
2. Law of Independent Assortment

Question 2

LAW OF SEGREGATION

Answer 2

• Alternate versions of genes (alleles) account for variations in inherited characteristics
• An organism inherits two genes, one from each parent (diploid), and only passes one on

Question 3

LAW OF INDEPENDENT ASSORTMENT

Answer 3

• Each gene equally likely to be transmitted when gametes (eggs and sperm) are formed
• Traits are independent of each other, the presence of one trait does not affect the likelihood of another trait.

Question 4

CROSSING-OVER

Answer 4

During meiosis, chromosomes can break and recombine forming new combinations of alleles that did not exist in the parents

Question 5

LOCI

Answer 5

The specific locations of genes on chromosomes

Question 6

LINKAGE

Answer 6

Genes carried on the same chromosome (tend to be inherited together)

Question 7

UNLINKED

Answer 7

When genes are found on different chromosomes or far apart on the same chromosome (feeble chance to be inherited together

Question 8

LINKAGE REDUCES THE RATE OF RECOMBINATION, BUT…

Answer 8

Does not eliminate it completely; depends in part on the distance between the two loci

Question 9

GENOTYPES AND PHENOTYPES

Answer 9

• Same phenotypes can arise from different genotypes
  E.g. BB = yellow peas, Bb = yellow peas
• Same genotype can yield different phenotypes depending on development and environment

Question 10

PUNNET SQUARES

Answer 10

A square diagram that is used to predict the genotypes of a particular cross or breeding experiment

Question 11

DOMINANT AND RECESSIVE: PEAS

Answer 11

Dominant: round, smooth, yellow seed, green pod, purple flower, along stem, tall stem

Recessive: wrinkled, green seed, yellow pod, white flower, flower at tip, short stem

Question 12

DOMINANT AND RECESSIVE: BLOOD

Answer 12

Dominant: A and B type

Recessive: O type

AA or AO = A blood type

BB or BO = B blood type

OO = O blood type