Review 4 Genetics, Meiosis, and Biotechnology

Question 1

Prophase I: Synapsis

Answer 1

homologous chromosomes line up

Question 2

Prophase I: Crossing Over

Answer 2

non-identical sister chromatids exchange DNA, occurs at chiasmata, recombination

Question 3

Metaphase I

Answer 3

Random orientation: homologous chromosomes line up randomly in the middle of the cell

Question 4

Anaphase I

Answer 4

spindle fibers pull homologous chromosomes to opposite ends of the cell, independent assortment

Question 5

Telophase I

Answer 5

Reduction division: cytoplasm divides each new cell is now haploid

Question 6

Prophase II

Answer 6

New meiotic spindle forms

Question 7

Metaphase II

Answer 7

chromosomes (made of sister chromatids) line up along the middle of the cell

Question 8

Anaphase II

Answer 8

centromeres break, sister chromatids separate, one copy of each is pulled to opposite poles of the cell

Question 9

Telophase II

Answer 9

cytoplasm divides: 4 haploid cells that are genetically unique

Question 10

Non-disjunction

Answer 10

failure of sister chromatids to separate (anaphase II) or cells produced are missing a chromosome or have an extra

Question 11

How is non-disjunction diagnosed?

Answer 11

Karyograms

Question 12

Genetics

Answer 12

science of heredity

Question 13

Genes

Answer 13

heritable factors (DNA) that determine specific traits (code for proteins)

Question 14

Genome

Answer 14

The complete set of all DNA base sequences of an organism

Question 15

Alleles

Answer 15

different forms of genes

Question 16

Sex-linked traits are more commonly seen in

Answer 16

Males (xy)

Question 17

Polygenic

Answer 17

genes with multiple alleles, show continuous (bell-shaped) variation

Question 18

Mutation: Base Substitution

Answer 18

one base in DNA changed; causes wrong codon in mRNA; causes wrong amino acid in translation

Question 19

Heterozygous dihybrid crosses

Answer 19

shows phenotypic ratio of 9:3:3:1