BIOLOGY HIGH SCHOOL

Body defenses that respond to generalized tissue damage and many common pathogens are referred to as

Answers

Answer 1
Answer: Body defenses that respond to generalized tissue damage and many common pathogens are referred to as nonspecific mechanisms. It refers to the innate immune system. It is an essential system of the overall immune system of the body as it consists of cells and mechanisms that would defend the body from infection. Example would be the skin. It is the very first line of defense of the body against any foreign materials. It  acts an almost impenetrable barrier to pathogens keeping them outside. The skin has oils and sweat making it acidic so it inhibits the growth of a number of microorganisms.

Related Questions

HIGH SCHOOL

1. Evidence of a chemical change include a. Change in size
b. Change in color
c. Change in shape
d. Change in weight/mass

2. Which of these would indicate a chemical change has occurred? a. Salt dissolves in water
b. A child colors a picture with a crayon
c. Solid iron is heated until it turns into a liquid
d. A metal is added to an acid and hydrogen gas is formed

Answers

Explanation:

1).  A change that does not bring any difference in chemical composition of a substance are known as a physical change.

For example, shape, size, mass, volume, density, etc of a substance are all physical changes.

And, a change that brings difference in chemical composition of a substance is known as chemical change.

For example, precipitation, reactivity, toxicity etc are chemical changes.

Change in color also depicts a chemical change but not always.

Hence, we can conclude that evidence of a chemical change include change in color.

2).    When salt dissolves in water then it is a physical change. This is because salt dissociates into ions and does not chemically combine with water.

A child colors a picture with a crayon is also a physical change since no change in chemical composition is taking place.

Solid iron is heated until it turns into a liquid depicts change in state of substance. Hence, it is a physical change.

A metal is added to an acid and hydrogen gas is formed  shows a chemical change as formation of gas only occurs due to change in chemical composition of a substance.

Thus, we can conclude that a metal is added to an acid and hydrogen gas is formed would indicate a chemical change has occurred.

1.- b. Change in color.

It's change in color because the other can happen by via a physical change.

2.- d. A metal is added to an acid and hydrogen gas is formed.

A chemical change results in change of an object chemical structure being disrupted or altered.

HIGH SCHOOL

The R and Y genes are 15 maps unit from each other on chromosome 2. A botanist sets up a parental cross between a true breeding yellow flowered plant with red tomatoes and a plant that is true breeding, double-recessive for the Y and R genes. What are the expected frequencies of the recombinant and parental gamete genotypes produced by the F1 plants? Choose all correct answers. The total percentage of gametes with recombinant genotypes will be 15%. Each recombinant gamete genotype will be produced 7.5% of the time. The total percentage of gametes with parental genotypes will be 100%. Each recombinant gamete genotype will be produced 25% of the time. Each parental gamete genotype will be produced 50% of the time. The total percentage of gametes with recombinant genotypes will be 50%. The total percentage of gametes with parental genotypes will be 85%. Each parental gamete genotype will be produced 42.5% of the time.

Answers

Answer options:

  • The total percentage of gametes with recombinant genotypes will be 15%.
  • Each recombinant gamete genotype will be produced 7.5% of the time.
  • The total percentage of gametes with parental genotypes will be 100%.
  • Each recombinant gamete genotype will be produced 25% of the time.
  • Each parental gamete genotype will be produced 50% of the time.
  • The total percentage of gametes with recombinant genotypes will be 50%.
  • The total percentage of gametes with parental genotypes will be 85%.
  • Each parental gamete genotype will be produced 42.5% of the time.

Answer

Explanation:

Map units are an arbitrary measurement based on the number of recombinants in a cross. Alleles on the same chromosome can only be inherited separately if crossing over occurs between them (i.e. genetic material is exchanged between different chromosomes).

The closer genes are together on a chromosome the less likely this is to occur and therefore the fewer number of recombinant phenotypes will be present.

Recombinant phenotypes are those that do not match the parents, i.e. a plant with non-yellow flowers and red tomatoes or yellow flowers and non-red tomatoes. If they are 15 map units apart, that means recombinant phenotypes when crossing 2 heterozygous individuals (F2 generation) only occur 15% of the time.

This cross is between  2 true breeding plants: YYRR x yyrr

The first parent can only produce YR gametes, and the second parent can only produce yr gametes.

Therefore, all the F1 offspring will be YyRr

The potential gametes for the F2 generation are YR, yr, Yr, yR. However, we know that Y and R are fairly close on the same chromosome. 15 map units apart means they only recombine to give yR or Yr phenotypes 15% of the time.

  • The total percentage of gametes with recombinant genotypes will be 15%.  - true
  • Each recombinant gamete genotype will be produced 7.5% of the time. - true - the combination is 15% made up of approximately 7.5% each
  • The total percentage of gametes with parental genotypes will be 100%. false it will be 100%-15% = 85%
  • Each recombinant gamete genotype will be produced 25% of the time. false
  • Each parental gamete genotype will be produced 50% of the time.
  • The total percentage of gametes with recombinant genotypes will be 50%. false
  • The total percentage of gametes with parental genotypes will be 85%.  true
  • Each parental gamete genotype will be produced 42.5% of the time. true, the combination is 42.5+42.5 = 85%
HIGH SCHOOL

Among humans, you can observe that there is variability in shape (size), skin color, and other traits. The variety in a small population results from ___ in either sexual reproduction or meiosis.

Answers

Answer:

Crossing over, independent assortment and random fusion of gametes

Explanation:

Sexual reproduction creates variations by any of the three processes:  

A) Exchange of genetic material between the non-sister chromatids of homologous chromosomes during prophase I of meiosis produce new gene combinations.

B) Independent assortment of homologous chromosomes towards opposite poles during anaphase I of meiosis I produce genetic variations among the daughter cells.

C) The random fusion of the gametes formed by meiosis further add genetic variations.  

MIDDLE SCHOOL

which statement is a hypothesis? A)If the temperature increases, then crickets will chirp more. B)crickets are cooler than grasshoppers. C)Does temperature affect how much crickets chirp? D)I hear crickets in the summer, so crickets chirp more when it's warm outside.

Answers

A hypothesis usually starts with the word “if” so the answer is A

Answer:

C) Does the temperature affect how much crickets chirp

Explanation:

A hypothesis is a question that you test through study and experimentation. Basically a hypothesis is an educated guess that you attempt to prove write(it could be wrong) through an experiment

HIGH SCHOOL

What hypothesis did Darwin investigate by studying the breeding of pigeons with distinctive traits? New species can appear gradually through small changes in an ancestral species.
The amount of variation in a population is related to the type of environment it lives in.
Organisms have only the number of offspring that are supported by the environment.
Some traits appear in each generation, while others seem to disappear in some generations.



Update: The correct answer is A

Answers

Answer:

New species can appear gradually through small changes in an ancestral species.

Explanation:

The new species that appear are due to hereditary variations that occur in a population. The adaptive variations are said to confer a selective advantage to organisms possessing them. The result of variations is that well adapted individuals are able to survive and reach the reproductive age and pass over their favourable characteristics to their offspring.

Answer: A

Explanation:

MIDDLE SCHOOL

Explain two ways in which xylem is modified to carry out its function

Answers

The most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called vessels. Xylem also contains two other cell types: parenchyma and fibers.
HIGH SCHOOL

Retroviruses become proviruses integrated into the host chromosome soon after infecting the host cell, and can remain there indefinitely. The provirus DNA can then be transcribed and translated by the host cell, making new retroviral RNA genomes, enzymes, and structural proteins. New retroviral virions can then assemble and bud through the host cell membrane continuously over long periods of time. What is one implication of this retroviral life cycle?

Answers

Retroviruses become proviruses integrated into the host chromosome soon after infecting the host cell, and can remain there indefinitely. The provirus DNA can then be transcribed and translated by the host cell, making new retroviral RNA genomes, enzymes, and structural proteins. New retroviral virions can then assemble and bud through the host cell membrane continuously over long periods of time. What is one implication of this retroviral life cycle?

a) Because retroviruses have multiple enzymes (reverse transcriptase, protease, and integrase), they can rapidly kill the host cell once enough of these enzymes are synthesized by the host.

b) Once many new virus particles are produced, the host cell will lyse to release them.

c) Retroviruses have a typical one-step viral growth curve, which leads to the host being overwhelmed quickly.

d) It is difficult to completely cure an animal host of the virus, since anti-retroviral drugs will only eliminate circulating virions, not proviruses.

Answer:

d) It is difficult to completely cure an animal host of the virus, since anti-retroviral drugs will only eliminate circulating virions, not proviruses.

Explanation:

When retroviruses integrate their genome into the host chromosome, it becomes difficult to cure them. This is due to the fact that the drugs used to cure the infection would target only virions present in the animal host. However, the presence of retroviral genome as provirus would lead to the formation of new virion progeny continuously. Therefore, killing the circulating virions does not eliminate the virus completely from the host body.

COLLEGE

Why is a genetically diverse population more likely to survive a change to the environment apex?

Answers

A genetically diverse population would more likely survive a change in the environment because they are more likely to have potential to adapt to the change. Since adaptations are a result of favorable mutations in an organism, the more genetically diverse the organism is, the more possibilities there are for different adaptations.

Answer:

The population  will have more possible adaptations. apex.

HIGH SCHOOL

Which characteristic stated below shows how property allows multicellular algae, like red, green and brown algae, to make the maximum use of sunlight? A. The presence of accessory photosynthetic organs other than the chloroplasts helps algae in absorption of the maximum amount of sunlight. B. The presence of Chlorophyll a, b, and c and various accessory pigments help absorb light at various wavelengths. C. The flattened body surface of the algae increases the area of absorption for sunlight, which allows algae to make the maximum use of sunlight.

Answers

I think the correct answer from the choices listed above is option B. Multicellular algae use the presence of Chlorophyll a, b, and c and various accessory pigments help absorb light at various wavelengths to make the maximum use of sunlight. Hope this answers the question.
Random Questions