All Chapters
Ch. 1 - Introduction to Biology
Ch. 2 - Chemistry
Ch. 3 - Water
Ch. 4 - Biomolecules
Ch. 5 - Cell Components
Ch. 6 - The Membrane
Ch. 7 - Energy and Metabolism
Ch. 8 - Respiration
Ch. 9 - Photosynthesis
Ch. 10 - Cell Signaling
Ch. 11 - Cell Division
Ch. 12 - Meiosis
Ch. 13 - Mendelian Genetics
Ch. 14 - Chromosomal Theory of Inheritance
Ch. 15 - DNA Synthesis
Ch. 16 - Gene Expression
Ch. 17 - Regulation of Expression
Ch. 18 - Viruses
Ch. 19 - Biotechnology
Ch. 20 - Genomics
Ch. 21 - Development
Ch. 22 - Evolution by Natural Selection
Ch. 23 - Evolution of Populations
Ch. 24 - Speciation
Ch. 25 - History of Life on Earth
Ch. 26 - Phylogeny
Ch. 27 - Prokaryotes
Ch. 28 - Protists
Ch. 29 - Plants
Ch. 30 - Fungi
Ch. 31 - Overview of Animals
Ch. 32 - Invertebrates
Ch. 33 - Vertebrates
Ch. 34 - Plant Anatomy
Ch. 35 - Vascular Plant Transport
Ch. 36 - Soil
Ch. 37 - Plant Reproduction
Ch. 38 - Plant Sensation and Response
Ch. 39 - Animal Form and Function
Ch. 40 - Digestive System
Ch. 41 - Circulatory System
Ch. 42 - Immune System
Ch. 43 - Osmoregulation and Excretion
Ch. 44 - Endocrine System
Ch. 45 - Animal Reproduction
Ch. 46 - Nervous System
Ch. 47 - Sensory Systems
Ch. 48 - Muscle Systems
Ch. 49 - Ecology
Ch. 50 - Animal Behavior
Ch. 51 - Population Ecology
Ch. 52 - Community Ecology
Ch. 53 - Ecosystems
Ch. 54 - Conservation Biology
Sections
Genes & Alleles
Homologous Chromosomes
Life Cycle of Sexual Reproducers
Introduction to Meiosis
Meiosis I
Meiosis II
Genetic Variation During Meiosis
Mitosis & Meiosis Review

Concept #1: Genetic Variation During Meiosis

Practice: Which of the following processes occurs when homologous chromosomes cross over in meiosis I?

a) Two sister chromatids get tangled, resulting in one re-sequencing its DNA.

b) Two sister chromatids exchange identical pieces of DNA.

c) Maternal alleles are "corrected" to be like paternal alleles and vice versa.

d) Corresponding segments of non-sister chromatids from homologous chromosomes are exchanged.

Practice: Crossing over involves each of the following EXCEPT:

a) The transfer of DNA between two non-sister chromatids.

b) The transfer of DNA between two sister chromatids.

c) The formation of a synaptonemal complex.

d) The alignment of homologous chromosomes.

e) All of the above are involved in crossing over.

Concept #2: Independent Assortment

Example #1: For a species with a haploid number of 23 chromosomes, how many combinations of maternal and paternal chromosomes are possible for the gametes based on the independent assortment of chromosomes during meiosis?

Practice: How many genetically unique gametes can be created in an organism with 4 chromosomes?

a) 256.

b) 23.

c) 16.

d) 1 million.

e) 4.

Practice: During which of the following processes does independent assortment of chromosomes occur?

a) In meiosis I only.

b) In meiosis II only.

c) In mitosis and meiosis I.

d) In mitosis and meiosis II.

e) In meiosis I and meiosis II.

Practice: Independent assortment of chromosomes is a result of which of the following processes?

a) The random way each pair of homologous chromosomes lines up at the metaphase plate.

b) The random combinations of eggs and sperm during fertilization.

c) The random distribution of the sister chromatids into the two daughter cells.

d) The diverse combination of alleles that may be found within any given chromosome.

Concept #3: Nondisjunction

Practice: Non-disjunction means that chromosomes:

a) Do not cross over during synapsis.

b) Do not replicate during interphase.

c) Have serious mutations.

d) Do not separate correctly from one another during anaphase.

Practice: During meiosis, if nondisjunction occurs during anaphase II (shown below in cell #3) what are the possible gametes that can be produced from cell #3?

a) A only.

b) B only.

c) C only.

d) A & C.

e) B & C.

f) A & B.

g) All three.

Practice: ________ cells have an extra or missing chromosomes after meiosis due to nondisjunction during Meiosis I.

a) Somatic cells.

b) Gametes.

c) Diploid Cells.

d) Aneuploid Cells.

e) Haploid Cells.

f) Sperm Cells.