Heredity

Question 1

What are the two things that Gregor Mendel is credited with the discovery of?

Answer 1

Segregation and independent assortment

Question 2

Segregation

Answer 2

Refers to the segregation of alleles in gametes

Question 3

Independent Assortment

Answer 3

Alleles assort independently; the migration of one allele does not affect the migration of another

Question 4

What are different generations called?

Answer 4

P (paternal), F1(filial), F2 (in order)

Question 5

Monohybrid cross

Answer 5

A genetic cross investigating only one trait

Question 6

Dihybrid cross

Answer 6

A genetic cross investigating two traits

Question 7

Complete dominance

Answer 7

When a dominant allele causes a trait to be expressed completely over a recessive one: they don’t share

Question 8

Test cross

Answer 8

When one mates an unknown-genotype plant with another known-genotype plant in order to determine its genotype

Question 9

Incomplete dominance

Answer 9

Instead of complete dominance, the traits kind of mix (example: snapdragons with one pink and one white allele are pink)

Question 10

Codominance

Answer 10

Both alleles are expressed, but they don’t mix. Think a piebald horse.

Question 11

Explain why blood transfusions aren’t universal

Answer 11

There are six different alleles mixes for the different blood types (i, IA, IB), which indicate which (if any) sugars they have attached to the person’s cells. If the person gets a kind of blood with sugars that don’t match, their immune system will attack it, leading to agglutination and possible death.

Question 12

Polygenic Inheritance

Answer 12

The interaction of many genes to create one phenotype. . This is often expressed a a continuous variation.

Question 13

Linked genes

Answer 13

Genes that are physically located close to each other and therefore do not segregate separately, and are usually inherited together. A linkage map is one made by evaluating the recombination frequencies to theorize about which genes are close.

Question 14

Autosome

Answer 14

chromosomes that aren’t sex chromosomes

Question 15

Sex limited traits

Answer 15

Traits that are limited by one sex chromosome (it has sections that code for how active regions on autosomes will be), such as male baldness

Question 16

Sex linked traits

Answer 16

Traits that reside on a sex chromosome. Usually X chromosome, since Y chromosome is small.

Question 17

X-inactivation

Answer 17

When, in females, one X chromosomes remains coiled in a Barr body as opposed to unfurling into chromatin. This happens independently in each cell, so not all cells in a female body are functionally the same.

Question 18

Nondisjunction

Answer 18

The failure of one or more chromosome pairs/ chromatids of a single chromosome to properly move to opposite poles during meiosis or mitosis.

Question 19

Give examples of nondisjunction

Answer 19

1. During meiosis, the failure of two homologous chromosomes to separate (trisomy 21)
2. During meiosis, one cell getting confused and its decedents being confused too
3. Too many gametes, causing polyploidy in a zygote

Question 20

Point mutation

Answer 20

When a different nucleotide takes the place of the intended one (substitution), one is deleted (deletion), or one is inserted (insertion)

Question 21

Aneuploidy

Answer 21

A genome with extra or missing chromosomes (trisomy 21(down syndrome) Turner syndrome)

Question 22

Chromosomal aberrations

Answer 22

When chromosome segments are changed (duplicated or squashed onto another chromosome).

Question 23

Non-Nuclear Inheritence

Answer 23

Mitochondria and chloroplasts carry their own DNA and reproduce by themselves (this is endosymbiotic theory that mitochondria and chloroplasts used to be other organisms that lived with us)