Chapter 10

Question 1

What plant did Mendel study?

Answer 1

Pisum sativum, the garden pea plant.

Question 2

List three characteristics of the Garden Pea Plant.

Answer 2

Plant is self-fertilizing, flowers produce both male and female gametes, one lineage of the plant can “bleed true” for certain traits.

Question 3

What are Monohybrid Experiments?

Answer 3

Tests that check for dominant or recessive alleles at one locus. (Aa x AA)

Question 4

What are Punnett Squares?

Answer 4

A grid used to calculate the probability of genes.

Question 5

What is a testcross?

Answer 5

One individual of an unknown genotype is cross with another that is homozygous recessive.

Question 6

What is Mendel’s Theory of Segregation?

Answer 6

Diploid cells have pairs of genes, on pairs of homologous chromosomes. The two genes of each pair are separated from each other during meiosis, so they end up in different gametes.

Question 7

What are Dihybrid Experiments?

Answer 7

They test for dominant or recessive allele at two loci. (AABB x AaBB)

Question 8

What is the Theory of Independent Assortment?

Answer 8

After meiosis ends, the genes on each pair of homologous chromosomes are sorted into gametes independently of how genes on other pairs of homologues are sorted out.

Question 9

What is Codominance?

Answer 9

Nonidentical alleles for a gene are both fully expressed; neither is dominant or recessive in heterozygotes. Codominance may occur in multiple allele systems.

Question 10

What is Incomplete Dominance?

Answer 10

One allele of a pair is not fully dominant over its partner, so the heterozygote’s phenotype is somewhere between the two homozygotes.

Question 11

What is Epistasis?

Answer 11

Interactions among products of two or more gene pairs. Two or more gene products influence a trait.

Question 12

What is Pleiotropy?

Answer 12

When one gene influences two or more traits.

Question 13

What is Marfan Syndrome?

Answer 13

A genetic disorder that arises by mutations in the fibrillin gene. Long, thin fibers of fibrillin protein impart elasticity to many tissues—heart, skin, blood vessels, skeleton, and tendons.

Question 14

What is all the genes on one chromosome called?

Answer 14

One linkage group. Humans have 23 linkage groups.

Question 15

What is the outcome of crossing over between a pair of homologous chromosomes disrupts gene linkages.

Answer 15

The outcome is recombination of alleles between homologous chromosomes.

Question 16

Individuals of populations generally show a range of small differences in most traits. What is this called?

Answer 16

Continuous variation.

Question 17

What is Polygenic Inheritance?

Answer 17

The inheritance of multiple genes that affect a trait.

Question 18

List the seven traits Mendel studied.

Answer 18

1. Seed Shape (round/wrinkled)2. Seed Colour (green/yellow)3. Pod Shape (Inflated/wrinkled)4. Pod Colour (green/yellow)5. Flower Colour (purple/white)6. Flower Position (along stem/at tip)7. Stem Length (tall/dwarf)