*Unit 5 Part 2: Mendel & Basics of Genetics

Question 1

Genetics

Answer 1

The study of genes and heredity

Question 2

Heredity

Answer 2

Passing traits from parents to offspring

Question 3

Who was the father of genetics?

Answer 3

Gregor Mendel

Question 4

Gregor Mendel

Answer 4

~Father of Genetics
~1822-1884
~Austrian monk
~Performed crosses (experimental breeding) with the garden peas at his monastery
~Made laws of heredity based on analysis of how traits are inherited

Question 5

Trait

Answer 5

Any observable characteristic

Question 6

Genes

Answer 6

DNA that holds information for a trait

Question 7

Allele

Answer 7

One version of a trait

Question 8

Diploid organisms (such as humans) have _____ of each gene.

Answer 8

2 copies

Question 9

When one allele masks the effect of another, that allele is called _____ and the other _____.

Answer 9

dominant; recessive

Question 10

Diploid

Answer 10

Containing 2 copies of each chromosome, making genes occur in pairs

Question 11

Genotype

Answer 11

Gene combinations for a trait
Ex. RR, Rr, rr

Question 12

Homozygous

Answer 12

Two of the same alleles
Ex. RR rr

Question 13

Heterozygous

Answer 13

Two different alleles
Ex. Rr

Question 14

Phenotype

Answer 14

The physical feature resulting from the genotype

Question 15

Each alleles is written as a letter that usually comes from the _____ allele.

Answer 15

dominant

Question 16

_____ is uppercase.

Answer 16

Dominant

Question 17

_____ is lowercase.

Answer 17

Recessive

Question 18

Write the genotype in words.
RR

Answer 18

Homozygous Dominant (Purebred)

Question 19

Write the genotype in words.
Rr

Answer 19

Heterozygous (Hybrid)

Question 20

Write the genotype in words.
rr

Answer 20

Homozygous Recessive (Purebred)

Question 21

Parental P1 Generation

Answer 21

The original parental generation

Question 22

F1 Generation

Answer 22

The first generation offspring

Question 23

F2 Generation

Answer 23

The second generation offspring comes from breeding individuals from the F1 generation

Question 24

What did Mendel observe?

Answer 24

1. Crossed parental generation
   ~Purebred white (pp) x purebred purple (PP) flower
2. Crossed F1 Generation
   ~All had purple petals (Pp) x (Pp)
3. Crossed F2 Generation
   ~Whites reappeared
   ~25% PP
   ~25% pp
   ~50% Pp

Question 25

Law of Segregation

Answer 25

~You can only pass one copy of your genes to your offspring
~Child gets second copy from other parent

Question 26

Law of Independent Assortment

Answer 26

~The allele you pass on of one trait does not affect what allele get passes on for a different trait in a gamete
~Ex. eye color does not affect height

Question 27

Law of Dominance

Answer 27

~Alleles that are recessive are masked by dominant alleles when both are present

Question 28

Polygenic

Answer 28

~”many genes”
~Several genes influence a trait
~Show a range of traits
~Are harder to study than single-gene traits

Question 29

List examples of polygenic traits in humans.

Answer 29

~Eye color
~Weight
~Height
~Hair
~Skin color

Question 30

What are the exceptions to the law of Dominance?

Answer 30

~Incomplete dominance
~Codominance

Question 31

Incomplete Dominance

Answer 31

Alleles blend

Question 32

Codominance

Answer 32

Alleles show up together