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Question 1

Gene/genome/genotype

Answer 1

A gene is a short stretch of DNA that codes for a characteristic. A genome is all the genetic information an individual possesses within their DNA. A genotype is the alleles an individual carries within their genes.

Question 2

X-linked versus Y-linked genes

Answer 2

X-linked genes determine sex, while Y-linked genes control characteristics unrelated to sex. Sons and daughters have an equal probability of inheriting a recessive allele of an X-linked genetic disorder from their mother, but only the sons can inherit Y-linked genetic disorders from their father.

Question 3

Sickle cell anemia

Answer 3

Sickle cell anemia is caused by one single-base substitution mutation (GLU to VAL). The new shape of the sickled red blood cells causes them to clump together easier and clog blood vessels.

Question 4

Haploid versus diploid cells

Answer 4

Haploid cells have one copy of each chromosome (non-homologous, I I I), whereas diploid cells have two copies of each chromosome (homologous, II II II).

Question 5

Amniocentesis

Answer 5

Amniocentesis is a prenatal test that takes amniotic fluid from the uterus, around an individual’s baby to test if the baby has certain health conditions.

Question 6

Chorionic villus sampling

Answer 6

Chorionic villus sampling is a prenatal test that takes a sample of tissue from the placenta to test if the individual’s baby has any genetic or chromosomal conditions.

Question 7

What happens during MITOSIS (prophase, metaphase, anaphase, telophase)?

Answer 7

Mitosis produces two genetically identical daughter cells from a single parent cell. PROPHASE: Chromosomes condense forming two chromatids. Nuclear membrane disintegrates causing the spindle to form. METAPHASE: Spindle organizes condensed chromosomes on the equator of the cell. Some spindle fibers attach to the centromeres and some span the cell. M-checkpoint occurs. ANAPHASE: Some spindle fibers shorten which pull the chromatids apart. Some spindle fibers lengthen which cause cell to elongate. TELOPHASE: Two new nuclei form

Question 8

Miller-Urey experiment

Answer 8

The Miller-Urey experiment simulated the conditions of early-Earth. The experiment showed that biological molecules that are essential for life can be synthesized abiotically from simpler substances.

Question 9

Binary fission

Answer 9

Binary fission is a type of asexual reproduction that involves a parent cell dividing, resulting in 2 identical cells. The process starts with the parent cell preparing for reproduction by replicating the DNA. Then, the 2 DNA molecules each attach to a different part of the cell membrane and build more membrane to elongate the cell. Then, the cells successfully divide.

Question 10

Outline MEIOSIS I (prophase I, metaphase I, anaphase I, and telophase I)

Answer 10

Meiosis produces 4 cells containing half of the original amount of DNA from the parent cell, which divides twice. PROPHASE I: Nuclear membrane dissolves, spindle fibers start to undergo crossing over. METAPHASE I: Paired chromosomes line up at the equator of the cell, a spindle fiber attaches to each pair. ANAPHASE I: Spindle fibers pull the paired chromosomes apart. TELOPHASE I: Paired chromosomes arrive at opposite poles of the cell and nuclear membrane may reform.

Question 11

Outline MEIOSIS II (prophase II, metaphase II, anaphase II, telophase II)

Answer 11

Meiosis produces 4 cells containing half of the original amount of DNA from the parent cell which divides twice. PROPHASE II: Nuclear envelope breaks, spindle fibers form between centrosomes. METAPHASE II: Unpaired chromosomes line up at the equator of the cell. ANAPHASE II: Unpaired chromosomes separate and are pulled to opposite poles of the cell. TELOPHASE II: Nuclear membranes begin to reform around new chromosomes, chromosomes decondense.

Question 12

Crossing over

Answer 12

Crossing over is the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.

Question 13

Nondisjunction

Answer 13

Nondisjunction is the failure of the non-sister chromatids to separate, which produces daughter cells with abnormal numbers of chromosomes. Nondisjunction can happen during mitosis, meiosis I, or meiosis II.

Question 14

Process of transpiration

Answer 14

Transpiration is a passive process involving water adhering to the cell wall and creating a film of water on the surface of cells, which allows water to evaporate from the cell wall into the air.

Question 15

Micropropagation

Answer 15

Micropropagation is a technology that produces large numbers of clones from an original parent plant.

Question 16

Divergent evolution versus convergent evolution

Answer 16

Divergent evolution is when two species have similar structures, but they function differently. Convergent evolution is when organisms aren’t closely related, but evolve similar structures that are used for similar purposes.

Question 17

Homologous structure versus analogous structure

Answer 17

Homologous structure refers to 2 things being similar in structure and evolutionary origin, but not function (ex: human arm & dolphin flipper). Analogous structure refers to 2 things being similar in function, but not structure or origin (orca fin & shark fin).

Question 18

Speciation, allopatric speciation, and sympatric speciation

Answer 18

Speciation occurs when 2 species become genetically different enough they can no longer interbreed. Allopatric speciation is when populations become geographically separated and establish reproductive isolation. Sympatric speciation is when a population forms a new species within the same area as the parent species.

Question 19

Detritivores versus saprotrophs

Answer 19

Detritivores versus saprotrophs

Question 20

Cane toads

Answer 20

Cane toads are an example of an alien/invansive species. They mass populated Australia due to the absence of natural predators, its rapid rate of reproduction, and the lethal toxin it produces.

Question 21

Peat

Answer 21

Peat is partially digested organic matter that forms in acidic, water-saturated soil. Peat contains large amounts of carbon that can be compressed into coal after a long period of time.

Question 22

Greenhouse gases, the greenhouse effect, and the enhanced greenhouse effect

Answer 22

Greenhouse gases are gases found in the atmosphere that contribute to the greenhouse effect. The greenhouse effect refers to the process by which heat is trapped near the Earth’s surface by greenhouse gases; this can cause the global temperature to rise and contribute to issues such as a decrease in biodiversity and an increase in storms and droughts. The enhanced greenhouse effect is the burning of fossil fuels that contribute to release of the greenhouse gas of carbon dioxide into the atmosphere. Additionally, the most common greenhouse gas is water vapor, along with carbon dioxide, methane, and nitrous oxide.

Question 23

Shortwave versus longwave radiation

Answer 23

Shortwave radiation is the only radiation from the sun that reaches the Earth’s surface. Longwave radiation are absorbed by greenhouse gasses and re-emmitted as heat.

Question 24

How does atmospheric carbon dioxide concentration affect marine organisms?

Answer 24

As the atmospheric carbon dioxide concentration increases, more carbon dioxide dissolves in the ocean which raises the ocean’s acidity to a degree that dissolves calcium carbonate resulting in marine organisms being unable to form or obtain their exoskeletons.