This controls the movement of substances into and out of the cell
The plasma membrane or cell membrane
True or False: Mutations can be a source of new alleles
True
Cyanobacteria are thought to be the first photosynthetic life-forms on Earth. They released this crucial element, forever changing the planet's atmosphere.
oxygen
This forms new allele combinations through independent assortment and crossing over.
Meiosis
When a small group of individuals colonize a new area, this population may be effected by this effect
The founder effect
This is the term for a fertilized egg after the joining of gametes
A zygote
True or False: In natural selection, selection that favors the intermediate phenotype is called stabilizing selection.
True
Mammals first appeared on the planet _____________ years ago.
200 million years ago
This type of selection is occurring in the following scenario: the existence of two distinct colors in a butterfly species
Disruptive selection
Changes in allele frequencies that are due to chance alone are called
Genetic drift
This is the portion of the cell cycle in which cells grow, carry out their normal functions, and prepare for cell division.
Interphase
True or False: An organism's genotype can always be clear from observing its phenotype.
False
Much is known about the planet's timeline due to the decay of some unstable elements and isotopes. This decay is measured in units specific to these elements and isotopes called their ________.
half-lives
This type of selection is occurring in the following scenario: a population of bacteria becoming increasingly resistant to antibiotics.
Directional selection
When a species nearly goes extinct but then rebounds, this effect occurs
The bottleneck effect
This is the name given to a group of related cells organized together to perform a specific function
Tissue
True or False: All human beings on Earth have exactly two sets of chromosomes.
False; some have one, some have two, some have three, some have four, though it is most common for a human to have two.
Early humans first appeared ____________ years ago.
200,000
Disruptive selection might eventually result in this type of evolution
Divergent evolution
Transcription converts a gene into a single-stranded _________ molecule.
RNA
This is an aqueous solution with a pH below 7
An acid
True or False: If a mutation occurs in an autosomal cell only, it can be inherited by offspring.
False
Of the following two groups, which contains more life-forms: hominoids or hominids
hominoids
The combined alleles in an entire population is known as this
The gene pool
Of the following: mRNA, rRNA, or tRNA, which brings amino acids from the cytoplasm to ribosomes to help make a growing protein
tRNA