1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Artemon [7]
3 years ago
7

You have conducted an Ames test on a given compound. Which of the following would be classified as a positive result on the Ames

test?
(A) His+ strain grows on an his- plate.
(B) His- strain grows on an his+ plate.
(C) His+ strain grows on either an his- or an his+ plate.
(D) His- strain grows on an his- plate.
(E) His+ strain grows on an his+ plate
Biology
2 answers:
Step2247 [10]3 years ago
8 0

Answer:

The correct answer is option (D) "His- strain grows on an his- plate".

Explanation:

The Ames test is a procedure that allows to detect if a given compound can cause mutations on a tested organism by growing strains of bacteria that require histidine (His-) to growth, since they are not able to produce its own histidine. In the Ames test, the bacteria is exposed to a given compound and is grown in a medium with small amount of histidine (his- plate). If the His- strain grows on a his- plate, it means that the bacteria has mutated to synthesize its own histidine and it is considered as a positive result on a the Ames test.

g100num [7]3 years ago
8 0

Answer:

(D) His- strain grows on an his- plate.

You might be interested in
Compare temperature and pressure conditions on the Earth's surface to those below the Earth's surface, and relate these conditio
Ivahew [28]

Answer:

Explanation:

The temperature and pressure on the earth's surface is lower than that below the earth's surface. Generally, temperature and pressure increases as you move/dig down the earth's surface. This increase in temperature and pressure causes the earth's sediment (below the earth surface) to form a compact solid rock - this process is known as lithification.

3 0
3 years ago
Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing sel
aliina [53]

Answer:

Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing selection

The Answer is option A (Disruptive selection)

Explanation:

Selection can either shift the mean value of a trait, reduce the trait's variation, or increase its variation.

Genetic variation which allows natural selection to increase or decrease frequency of alleles already in the population is a source of phenotypic variation as it refers to differences in all the hereditary information of members of the same species.

Disruptive Selection is important in maintaining variation and initiating speciation as it Increases Variation by favoring alleles corresponding to more extreme phenotypes. But for it to occur, the mean phenotype has to experience the lowest fitness. Disruptive selection affects the frequency distributions of alleles and genotypes within a population.

Disruptive selection is based on the variance of a trait in a population as it increases genetic variance by equalizing the frequencies of existing alleles at polymorphic loci (a genetic loci with two or more alleles). Disruptive selection maintains and may even increase variation in natural populations by favoring extreme phenotypes, individuals with extreme values for a trait have greater reproductive success than individuals with intermediate values.

7 0
4 years ago
Who studied mitosing cells
Aleks [24]

Answer:Margulis

She is the one who discovered it

3 0
4 years ago
Read 2 more answers
20<br> Compared with mitosis, the process of meiosis results in daughter cells<br> that are-*
USPshnik [31]

Answer:

D haploid (n) with a smaller number of chromosomes than the parent cells

Explanation:

meiosis results in gametes which have half the number of chromosomes and are therefore diploid because they have one set only. that is because later, the two cells with half the chromosomes (egg and sperm) join together to make a diploid cell

8 0
3 years ago
How does water clarity indirect effects on other species in food chain?
Vladimir [108]

Answer: The effects of which are devastating to human life, flora and fauna, which depend on these resources for their survival. Contamination of water causes disruptions of food chains and destruction of ecosystems. A deadly by-product of this water pollution is the spread of water-borne diseases such as cholera, typhoid etc.

Explanation:

3 0
2 years ago
Read 2 more answers
Other questions:
  • Humans must depend on the environment for their survival
    15·1 answer
  • Are fermentation reactions intracellular or extracellular? Explain.
    11·1 answer
  • What is the hardest tree in the world today? Enter your answer in the box below.
    5·2 answers
  • What term is defined as the basic unit of structure and function found in all living things?
    7·2 answers
  • Fertilization is a process that occurs during sexual reproduction.
    9·2 answers
  • 4. In snapdragons, a gone that affects flower color has two alleles: red (R) and white
    14·1 answer
  • The granite was helpful in helping the team find the lowest gravity spot because of its low
    12·2 answers
  • 11. Directions, identify the correct rock type in the diagram below.
    10·1 answer
  • 30 POINTS PLEASE HELP
    6·1 answer
  • Which of these statements best describes how scientific ideas change (multiple choice)
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!