Question 1

What is an allele?

Accepted Answer

A variant of a gene for a particular trait

Question 2

What are F₁ and F₂?

Accepted Answer

The first and second filial generations

The initial cross between two distinct plants, and the cross of sister seedlings from the first cross

Question 3

What is a genotype?

Accepted Answer

All the genes that make up an individual

(genotype = genes)

Question 4

What does it mean to be heterozygous for a gene?

Accepted Answer

The two alleles that make up that gene are different

(having one allele for red hair and one allele for brown hair)

Question 5

What does it mean to be homozygous for a gene?

Accepted Answer

The two alleles that make up that gene are the same

(having two alleles for red hair, or having two alleles for brown hair)

Question 6

What is a karyotype?

Accepted Answer

A technique for producing a chart of an individual's chromosomes

Question 7

What is nondisjunction?

Accepted Answer

Improper separation of chromosomes during meiosis, causing an abnormal number of chromosomes in offspring

(causes variety of disorders, such as Down, Turner, and Klinefelter syndromes)

Question 8

What is P₁?

Accepted Answer

The parent generation in a cross

Question 9

What is a phenotype?

Accepted Answer

Physical characteristics on an individual, resulting from how its genotype interacts with the environment

(physical characteristics = phenotype)

Question 10

What is a character in genetics?

Accepted Answer

A genetically inherited characteristic

Question 11

What was the blending hypothesis?

Accepted Answer

An incorrect hypothesis that stated offspring are a blend of their parents' genes

A blue flower and a yellow flower would make a green flower

(popular before Mendel's work in the 1850s; proven false)

Question 12

What is a monohybrid cross?

Accepted Answer

A cross between two organisms on a single trait

Question 13

What is a dihybrid cross?

Accepted Answer

A cross between two organisms on two different traits at once

Question 14

What is the law of segregation (Mendel's First Law)?

Accepted Answer

Every organism has a pair of alleles for each trait

These alleles segregate/separate when gametes for formed

Question 15

What is the law of independent assortment (Mendel's Second Law)?

Accepted Answer

The inheritance of one trait does not affect the inheritance of another

(technically: pairs of alleles are distributed independently when gametes are formed)

Question 16

What is the law of dominance?

Accepted Answer

When an organism is heterozygous for a trait, only the dominant allele will produce a phenotype

Question 17

What is a test cross?

Accepted Answer

A test created by Mendel to determine an organism's genotype

Geneticists breed an organism with an unknown genotype, with an organism that is homozygous recessive for a given trait, and analyze the offspring

Mendel, AP Biology Flashcards