15 questions
The four butterflies in the illustration represent the offspring in the F1 generation. Which statement is best supported by the phenotypes of these offspring?
The F1 generation is composed only of males.
Two of the offspring in the F1 generation will not be able to reproduce.
The F1 generation is the result of a dihybrid cross.
Two of the offspring in the F1 generation will experience a spontaneous mutation
The initial steps in gene expression are modeled. Double-stranded DNA first unwinds into two strands. Which process and product are represented in the diagrams?
Process: transcription; product: mRNA
Process: translation; product: protein
Process: replication; product: tRNA
Process: recombination; product: polymerase
The diagram represents one way an enzyme can be inhibited. Which statement explains the effect of an inhibitor on an enzyme?
A substrate will be able to bond with the enzyme.
The enzyme will likely be attacked by immune cells
The enzyme will be unable to produce more enzymes.
A substrate will be unable to attach to the enzyme.
Food webs such as the one shown were first used in 1927 by the animal ecologist Charles Elton. The food web below represents the feeding relationships among organisms in an Alaskan ecosystem. An environmental change that removed which of these organisms from the ecosystem would cause the most instability in the ecosystem?
Auklets
Foxes
Salmon
Zooplankton
An analysis of DNA and RNA sequences can be used to classify organisms. A dendrogram, such as the one shown, is based on molecular data. It can be used to represent evolutionary relationships within a group of organisms that are hypothesized to have descended from a common ancestor. Which statement is best supported by the information in this dendrogram?
Lesser pandas are more genetically similar to giant pandas than they are to raccoons.
Brown bears are more genetically similar to giant pandas than they are to sun bears.
Lesser pandas are more genetically similar to raccoons than they are to giant pandas.
The bear species are all more genetically similar to dogs than they are to giant pandas.
Some students used vinegar to dissolve a way the shells of three eggs and used these eggs as models of human red blood cells. The students observed the changes in the eggs when they were placed in different solutions. Which statement best describes the role of the cell membrane in this model?
The cell membrane is an impermeable barrier that prevents water from entering the cell.
The cell membrane allows solutions to enter the cell, which causes the cell to shrink.
The cell membrane allows water to enter and leave the cell.
The cell membrane removes solutes from the environment.
the section of dna has these bases:
TAG CAG TAC
which mRNA sequence is produced from this DNA section
ATC GTC ATG
AUC GUC AUG
AUG CUG AUC
UTC GTC UTG
Viruses are considered nonliving because they need a host to reproduce.
True
False
A cell _______ in a hypertonic solution because water moves _______ the cell.
shrinks; out
shrinks; in
swells; out
swells; in
Passive transport requires ATP while active does not.
True
False
Which of the following follows the concentration gradient (high to low) but requires a transport protein?
diffusion
osmosis
facilitated diffusion
active transport