Mendel Law Of Inheritance Continued

Question 1

What traits did Mendel follow with his pea plants

Answer 1

Dominant and recessive

Question 2

Law of Independent assortment

Answer 2

the alleles of two (or more) different genes get sorted into gametes independently of one another.

Question 3

Rules learned from monohybrid crosses

Answer 3

Alternative versions of genes (alleles) account for variation in traits.

For each trait, an organism inherits two copies of the gene (alleles) that governs that trait, one from each parent.

If alleles are different from each other, one allele dominates the phenotype (not always true).

The two alleles for a trait segregate equally in gametes. This is the law of independent segregation.

Question 4

Rules learned from dihybrid crosses

Answer 4

Alleles for different traits assort independently. This is the law of independent assortment. This law is not always correct!

Question 5

What do nost traits in plants and animals do not follow simple Mendelian inheritance patterns?

Answer 5

Most traits are governed by multiple alleles of multiple genes. Mendel’s laws still apply to each individual gene (allele pair).

Question 6

recessive alleles

Answer 6

In many (not all) cases, recessive alleles are non-functioning alleles.

Question 7

Polygenic

Answer 7

A trait controlled by many genes

Question 8

How many alleles can an individual have for each gene?

Answer 8

1 or 2 alleles

Question 9

Give 1 example of an inherited disorder carried by a single recessive allele.

Answer 9

Sickle cell anemia, albinism, tay-sachs, and/or cystic fibrosis

Question 10

What can continuous/quantitative traits result from?

Answer 10

Incomplete dominance or Co-dominance of alleles

More than two alleles are present in a population

Multiple genes (with multiple alleles) contribute to the trait

Genes can interact with the environment

Question 11

Incomplete dominance/Co-dominant alleles

Answer 11

Alleles that effect both the phenotype, and may appear to blend in heterozygotes.

Question 12

Mechanism 1

Answer 12

“Blending” can occur when alleles are Co-dominant or Incompletely dominant

Question 13

Mechanism 2

Answer 13

If there are more than 2 alleles for a given gene, there can be more variations on a trait

Question 14

What is Blood Type an example of?

Answer 14

A trait coded for by a single gene with 3 alleles, resulting in 4 different phenotypes.

Question 15

Mechanism 3

Answer 15

Polygenic traits are influenced by multiple genes

Question 16

Give an example of a quantitative trait

Answer 16

Skin color, height

Question 17

What does it mean when gene activity is “additive”?

Answer 17

Each gene independently adds to the expression of the trait.

Question 18

Mechanism 4

Answer 18

The environment may influence

Question 19

Multifactorial traits

Answer 19

Traits that have a genetic basis, but also respond to the environment

Question 20

Phenotypic plasticity

Answer 20

the ability to express a different phenotype based on environment.

Question 21

Cyclopia

Answer 21

The fusion of 2 eyes into one. Individuals with cyclopia also have a “proboscis” above the eyes and no nose, and their brains have fused right and left hemispheres. Most humans and animals are still born or die within 24 hours.

Question 22

Disprosopia

Answer 22

Separation of 1 face into 2

Question 23

SHH gene

Answer 23

Gene that dvivides the hemispheres of the brain. Too little or too much SHH expression in the midline of the brain can lead to conditions like cyclopia and disprosopia

Question 24

Cyclopamine

Answer 24

Chemical released by the corn lily in defense. Induces cylcopia in livestock when exposure occurs in the womb

Question 25

Morphological patterning

Answer 25

Patterning that occurs through interactions of specific genes (proteins) expressed by specific tissues with specific physical arrangements.

Question 26

What did Walter Sutton’s “Chromosomes in Heredity” argue?

Answer 26

Chromosomes are inherited, and can carry information about traits.

Question 27

Whst fid Thomas Morgan and his students use to test the hypothesis that genes reside on chromosomes?

Answer 27

Fruit flies