Lesson 1: Mendelian Genetics

Question 1

Gene

Answer 1

Segment of DNA

Question 2

Allele

Answer 2

Version of a gene

Question 3

Genotype

Answer 3

The combo of alleles that code for a trait

Question 4

Phenotype

Answer 4

The physical representation of a trait

Question 5

Homozygous

Answer 5

A genotype that contains 2 of the SAME alleles

Question 6

Heterozygous

Answer 6

A genotype that contains 2 different alleles

Question 7

Dominant

Answer 7

The version of a trait (phenotype) that is more commonly seen

Question 8

Recessive

Answer 8

The version of a trait (phenotype) that is less commonly seen

Question 9

The “blending” theory of inheritance

Answer 9

Before Mendel’s work, the most popular theory of inheritance that the qualities of the parents blended to form the qualities of the child (offspring)

Question 10

The “blending” theory of inheritance example

Answer 10

A tall parent and a short parent would produce a child of medium height

Question 11

Gregor Mendel

Answer 11

Was an Austrian monk who worked with pea plants, he was the first to identify units of heredity (genes)
—discredited the blending theory

Question 12

What did Gregor Mendel predict/conclude

Answer 12

—He was the first person to predict how traits were transferred from one generation to the next
—Concluded that inherited characteristics were carried in discrete, independent units (later called genes)

Question 13

Why did Mendel use peas: Reason 1

Answer 13

The common pea plant was available throughout Europe

Question 14

Why did Mendel use peas: Reason 2

Answer 14

It’s easy to grow and matures quickly

Question 15

Why did Mendel use peas: Reason 3

Answer 15

Pea plants self- pollinate, allowing Mendel to control which plants reproduced

Question 16

Why did Mendel use peas: Reason 4

Answer 16

Different varieties of pea plants have different traits that can be easily observed from one generation to the next

Question 17

Mendel’s Experiment p1

Answer 17

-Mendel selectively fertilized pea plants with the pollen from other plants and analyzed the hereditary patterns of certain traits via:
-obtaining purebred plants for the traits he wanted to study.
–A purebred organism results from many generations of
selective breeding.

Question 18

Mendel’s Experiment p2

Answer 18

-Plant height was one of the traits Mendel used in his studies of the pea plant.
-Once he had a purebred short and a purebred tall plant he would cross-pollinate them and observe the results
-Mendel called this purebred cross the P/Parent Generation

Question 19

Mendel’s Experiment p3– the results

Answer 19

-The offspring of the P generation is were called the F1 generation. These peas were all tall
-Mendel then cross-pollinated these plants with e/o and created the F2 generation. These plants were 75% tall and 25% short

Question 20

Mendel’s Conclusion— The principle of Dominance

Answer 20

These results led Mendel to conclude that the tall trait was dominant and the short trait was recessive

Question 21

Mendel’s Conclusion— The principle of segregation

Answer 21

Genes are normally paired but are separated during gamete formation

Question 22

Mendel’s Conclusion— The principle of of independent assortment

Answer 22

Each factor’s distribution in the gametes is not related to the distribution of any other factor