FR Chap 10 Mendel and Patterns of inheritance

Question 1

Heredity

Answer 1

Inheritance

Question 2

Genetics

Answer 2

The study of heredity

Question 3

Allele

Answer 3

Alternative form of a gene

Question 4

Gamete

Answer 4

Egg or sperm sex cell that contains a single set of chromosomes, one from each homologous pair.

Question 5

Homozygous (example as well)

Answer 5

having identical alleles for a gene.

Question 6

Heterozygous (example as well)

Answer 6

having different alleles for a gene.

Question 7

Diploid (human Chromosome Number)

Answer 7

Contain two homologous sets of chromosomes. The total number of chromosomes, 46 in humans, is referred to as the diploid number (abbreviated 2n, as in 2n=46).

Question 8

Haploid (Human chromosome number)

Answer 8

A cell with a single set of chromosomes is called a haploid. For humans, the haploid number (abbreviated n) is 23.

Question 9

Phenotype

Answer 9

observed traits of an organism.

Question 10

Genotype

Answer 10

genetic makeup of an organism; an organism’s combination of alleles.

Question 11

Homologous Chromosome

Answer 11

one of a matching pair of chromosomes, one inherited from each parent.

Question 12

Who was he father of genetics?

Answer 12

Gregor Mendel

Question 13

What was the organism of choice for first studying genetics? A reason why?

Answer 13

Pea plants. Mendel wanted to apply an experimental approach to the question of inheritance.

Question 14

In a monohybrid true-breeding cross, what ratio of the F1 is always expected?

Answer 14

3:1

Question 15

In a dihybrid heterozygous cross, what ratio is always expected?

Answer 15

9:3:3:1

Question 16

Sex-linked trait

Answer 16

Any gene that is located on a sex chromosome.

Question 17

Carrier

Answer 17

Individual who has one copy of the allele for a recessive disorder and does not exhibit symptoms.

Question 18

Pedigree

Answer 18

family tree that records and traces the occurrence of a trait in a family.

Question 19

What is the difference b/w incomplete and codominance? (Examples?)

Answer 19

The alleles Ia & Ib exhibit codominance, meaning that a heterozygote expresses both traits. Note that this is different from intermediate inheritance. The individual’s phenotype is not intermediate, but rather shows the separate traits of both alleles.

Question 20

Provide an example for Multiple Alleles and Polygenic Inheritance.

Answer 20

Suppose there are three “tall” alleles for each gene (A, B, & C), each of which contributes one “unit” of tallness to the phenotype. These tall alleles exhibit intermediate inheritance with three “short” alleles (X, Y, & Z). A person with genotype AABBCC would be very tall, a person eith genotype AXBBCC would be slighty less tall, & so on.