Chapter 3: Basic Principles of Heredity

Question 1

Why did Gregor Mendel choose to study pea plants?

Answer 1

1. Other research showed that pea hybrids could be produced
2. Many pea varieties were available
3. Peas are small plants and easy to grow
4. Peas can self-fertilize or be cross-fertilized

Question 2

What is a Gene

Answer 2

An inherited factor (region of DNA) that helps determine a characteristic

Question 3

What is an allele

Answer 3

One of two or more alternative forms of a gene

Question 4

What is a locus

Answer 4

a specific place on a chromosome occupied by an allele

Question 5

What is a genotype

Answer 5

Set of alleles possessed by an individual organism

Question 6

What is heterozygote

Answer 6

An individual organism possessing two different alleles at a locus

Question 7

What is homozygote

Answer 7

An individual organism possessing two of the same alleles at a locus

Question 8

What is a phenotype or trait

Answer 8

The appearance or manifestation of a characteristic

Question 9

What is true breeding?

Answer 9

homozygous for a trait

Question 10

What are true breeding parents called?

Answer 10

P generation

Question 11

What is the progeny of a P generation called?

Answer 11

Their progeny are called F₁ generation

Question 12

What is a monohybrid cross?

Answer 12

Cross between two parents that differ in a single characteristic

Question 13

What is the F2 progeny

Answer 13

Inter-breeding (self pollinating) F1 generation

Question 14

What is Mendel’s Law of Segregation?

Answer 14

Each individual diploid organisms possesses two alleles for any particular characteristic, one inherited from the maternal parents and one from the paternal parent. These two alleles segregate when gametes are formed and one allele goes into each gamete.

Question 15

What is the Principle of Independent Assortment

Answer 15

Each pair of alleles segregates independently of each other pair of alleles during gamete formation.

Genes close together on the same chromosomes will tend to be inherited together

Question 16

When do you use the multiplication rule

Answer 16

The probability that two or more independent events will occur together is the product of their individual probabilities

Look for AND

Question 17

When do you use the addition rule?

Answer 17

The probability that any one of two or more exclusive events will occur is calculated by adding together their individual probabilities.

Look for OR

Question 18

What is conditional probability?

Answer 18

Only possible genotypes should be considered as possibilities.

Example: Two parents are known to be heterozygous carriers for a disorder. What is the probability that the child is also a carrier? (⅔)

Question 19

What is the equation for binomial expansion?

Answer 19