Unit 5

Question 1

Meiosis Purpose

Answer 1

Make gametes (egg & sperm) with half the DNA (haploid), used in sexual reproduction to create genetic diversity

Question 2

Haploid

Answer 2

(n), 1 set of chromosomes

Question 3

Diploid

Answer 3

(2n), 2 sets of chromosomes: one from mom and one from dad

Question 4

Crossing Over & Recombination

Answer 4

Happens in Prophase 1, homologous chromosomes swap DNA which mixes genes and increases genetic diversity

Question 5

Homologous Chromosomes

Answer 5

Chromosomes pairs (one from mom, one from dad) with the same genes in the same order, but maybe different alleles

Question 6

Fertilization

Answer 6

When egg (n) and sperm (n) combine to form zygote (2n)

Question 7

Law of Segregation

Answer 7

Each parent gives only one allele for a gene to their offspring (alleles separate during meiosis)

Question 8

Law of Independent Assortment

Answer 8

Genes for different traits are inherited separately from each other if they are on different chromosomes

Question 9

Monohybrid Cross

Answer 9

Focuses on one trait (ie. Aa x Aa has genotype 1:2:1 and phenotype 3:1)

Question 10

Dihybrid Cross

Answer 10

Looks at 2 traits at once (ie. AaBb x AaBb has phenotype of 9:3:3:1)

Question 11

Magic Ratio

Answer 11

9:3:3:1, the dihybrid cross of two heterozygous parents

Question 12

Sex Linked Traits

Answer 12

Genes on the X chromosome (mom gives to sons, like colorblindness, dad gives to daughters)

Question 13

Linked Genes

Answer 13

Genes on the same chromosome that are inherited together unless crossed over

Question 14

Heterozygous

Answer 14

Two different alleles for a gene (Aa)

Question 15

Homozygous

Answer 15

Two same alleles for a gene (AA or aa)

Question 16

Dominant

Answer 16

One copy needed to show the trait

Question 17

Recessive

Answer 17

Two copies needed to show the trait

Question 18

Mitochondrial Inheritance

Answer 18

DNA outside of the nucleus of the egg, mother passes to all children

Question 19

Recombination Frequency (for Linked Genes)

Answer 19

Children with new allele combinations that are different than the parents which is caused by crossing over (number of recombinant, or unlike parents, divided by total children, times 100 equals the frequency %), if the answer is less than 50%, genes are linked

Question 20

Phenotypic Plasticity

Answer 20

One genotype can show different phenotypes depending on the environment (plant grows taller in sunlight than in shade)

Question 21

Nondisjunction

Answer 21

Chromosomes don’t separate correctly in meiosis, which leads to an extra or missing chromosome (ie. Down Syndrome)