Bio Midterm 3

Translate the following: DNA template: C G G T G A T C G mRNA: G C C A C U A G C

Ala-Thr-Ser

A disease-causing bacterium may be protected from the immune system by a slippery

Capsule

A population of rodents displays a variety of body sizes. The smallest individuals can easily hide from predators. The larger individuals sometimes do not find enough food to support their larger body size and have fewer hiding spots. What kind of natural selection do you think will result?

Directional Selection

In a shallow bay, a population of oysters is the food source for the local crabs. The lightest colored oysters blend with the color of the rocks, and the darkest colored oysters are concealed in the shadows cast by the rocks. Oysters with an intermediate coloring are easily detected by the crabs and become a tasty meal for them. Over time, fewer and fewer oysters display the intermediate coloring, while more oysters are either the lightest coloring or the darkest coloring. This is an example of

Disruptive Selection

Which of the following is NOT a feature of the genetic code?

Every individual has a different genetic code.

Many bacteria have a shorter generation time at warmer temperatures. Why do food safety guidelines recommend rapidly cooling leftover foods and maintaining them at refrigerator temperatures?

Many bacteria reach disease-causing levels rapidly when food is warm.

Natural selection acts directly on __________ that increase survival and reproductive success.

Phenotypes

When robins lay a clutch of more than four eggs, their chicks are often malnourished because they have so many to feed. If the robins lay fewer than four eggs, they may not have any viable offspring. As a result, robins typically lay a clutch of four eggs. This is an example of

Stabilizing selection

choose the correct complementary strand for ACG CAT GTG

TGC GTA CAC

Evolution can be described as

a change in the genetic characteristics of a population of organisms over time.

During transcription,

a template strand of DNA directs the production of an mRNA molecule.

The function of genes is to control the production of

all proteins.

The order of the bases in DNA determines the order of the

amino acids in mRNA.

Each set of three bases in an mRNA molecule codes for one of 20 specific

amino acids.

Convergent evolution produces

analogous traits

Which of the following are most well known for their ability to thrive in extreme environments that feature extremely high temperatures, high salt concentrations, or very acidic conditions?

archaeans

Disruptive selection operates whenever

both extremes of the phenotype are more successful.

Prokaryotes can be found in most habitats because they

can survive in both oxygen-rich and oxygen-free environments.

The importance of tRNA is that it

carries a specific amino acid to the mRNA.

Convergent evolution occurs when natural selection causes distantly related organisms to

evolve similar structures in response to similar environmental challenges.

Which of the following is the best description of polymerase chain reaction (PCR)?

fast, artificial DNA replication

The illustration shows an example of

gene transfer

Gene regulation is the ability to

increase or decrease protein synthesis from a given gene.

The following figure illustrates DNA undergoing replication. The region indicated by the red rectangular box represents a

mismatch error.

Which of the following is the only one that can generate new alleles?

mutation

The central driver of evolution is

natural selection

A smartphone app converts spoken English into Spanish. This is similar to the process by which __________ are converted into __________.

nitrogenous bases in mRNA; a sequence of amino acids

Heterotrophic bacteria and archaeans that are decomposers are important in

nutrient Cycling

One of the earliest prokaryotes on Earth, the cyanobacteria, played an important role in the evolution of multicellular eukaryotes. These early prokaryotes changed Earth's chemistry when they began

producing oxygen as a by-product of photosynthesis.

Damaged DNA may be repaired by a special class of

proteins.

Disease-causing bacteria in a human begin to multiply rapidly when they sense that their numbers are high enough to overpower an immune response. This is possible because of

quorum sensing.

DNA technology can be used with all organisms because they all

share the same chemical DNA structure.

Structures produced by bacteria, but not archaeans, that are extremely resistant to boiling and freezing temperatures are

spores

Consider a build-at-home bookshelf that comes with instructions and various pieces of wood as an analogy for translation. In this analogy, what would best match the job of the ribosome?

the person building the bookshelf

In the genetic code, a codon is __________ bases long for __________.

three; all cell types

Which of the following does NOT take place in the nucleus?

translation

The CRISPR method for genome editing uses a system made up of what molecules?

two RNA molecules plus Cas9 proteins

Which of the following is NOT a base found in DNA?

uracil

The sequence of DNA differs among individuals within a species. This is the reason for

variations in phenotypes.