The first organisms to appear on Earth did not need?
a. oxygen.
cells.
b. nitrogen
d chemicals
C
Please select the best answer from the choices provided
Ο Α
B
C

Answers

Answer 1
answer:
D

explanation:
Answer 2

Answer:

ANS IS DDDDDDDDDDDDDDDDDDDDDDDDDDDDDdd

Explanation:


Related Questions

Porcupines have long sharp hairs called quills. What is the main function of the quills on the porcupine?

Answers

Answer:protection from other predators.

Explanation: the quills will stick into a predator that attack the porcupine Note: it does NOT shoot its quills

Answer: protection from other predators.

What’s da answer yalll I need help ...

Answers

Answer:

I believe the answer is a missense mutation.

Explanation:

As it is a point mutation, a single nucleotide will provide a codon for a different chain of amino acids from that point on. This is a type of non-synonymous substitution.

Sasha is studying a rock formation for her science class. Every few days she goes outside to study the formation. The questions she is
investigating are shown.
• Did the rock freeze and
unfreeze?
• Are there any plants growing on
the rock?
• Did the rock change color?
What question is Sasha most likely trying to answer?
O A. What is the age of the rocks in the rock formation?
B. What type of rocks are found in the rock formation?
C What processes are weathering the rock formation?
D. What minerals are the hardest in the rock formation?

Answers

Answer:

ill say c

Explanation:

Histones are small proteins with a strong positive charge at physiological pH. They are found in the nuclei of eukaryotic cells and package DNA into nucleosomes, the fundamental structural units of chromatin. Based only on this description, what two forms of chromatography could you use, one after the other, to separate histones from other cellular proteins? Explain your reasoning.

Answers

Answer:

Two modes of chromatography that could be used over and over, based on characteristics of histones throughout the issue, are:

Size-exclusion Chromatography Ion exchange chromatography

Explanation:

Using size exclusion chromatography:

A stationary step, consisting of such a polymeric material with numerous pores of various sizes. The larger proteins would travel further as the solvent system comprising the analytes flows through the paper chromatography and therefore will be separated first. That was because their greater size does not in itself allow the pores found in the polymer to get trapped. Tiny proteins such as histones, and on the other hand, can pass slowly across the process to have been eluted later.

Using Ion exchange chromatography:

As even the histone properties at biological pH are strongly positively charged, through the use of highly reactive particles as when the stationary step will allow histones to connect to themselves and now all the proteins, as well as favorable proteins that are poorly absorbed, would be eluted. Many positively charged molecules, that aren't as highly charged at around the same pH as histones, will stay throughout the stationary step, however, based on whose net charge, should flow independently of histones.

The two classes of chromatography techniques include size-exclusion and ion exchange chromatography.

What are size-exclusion and ion-exchange chromatography?

Chromatography is a technique used in molecular biology laboratories to separate biomolecules.

Size exclusion chromatography is a technique capable of separating biomolecules according to size by using filtration in a gel.

Size exclusion chromatography is a technique capable of separating biomolecules and ions according to their affinity to a given ion exchanger.

In conclusion, the two classes of chromatography techniques include size-exclusion and ion exchange chromatography.

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Melanin is a that is produced in organelles called in specialized cells called ________.

Answers

Answer:

Melanocytes

Explanation:

Melanocytes produce the protective skin-darkening pigment melanin. Melanocyte, specialized skin cell that produces the protective skin-darkening pigment melanin. Birds and mammals possess these pigment cells, which are found mainly in the epidermis, though they occur elsewhere like in the matrix of the hair.

Melanin is a that is produced in organelles called in specialized cells called

Melanosomes

Melanin is a dark pigment that is found in the skin of a human. This factor affects the color of the eyes, hair, etc in people as the more melanin available in the body, the darker these parts of the body are.

A specialized cell is responsible for the production of melanin called melanosomes and this is in varying quantities in different people.

Melanosomes are those cell nucleus that are responsible for the production, storage and transfer of melanin to the parts of the body.

Therefore, the correct answer is melanosomes

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Which process do seeds undergo under favorable conditions?
elogation
fertilization
pollination
germination

Answers

Answer is Pollination

Answer:The answer is Germination

Explanation: I took the test

octopus and squid have chemoreceptors on their​

Answers

Answer:

tentacles

Explanation:

hope this helps :]

Answer:

octopus have chemoreceptors in the epidermis  

Explanation:

hope this helps a little

Which of the following mRNA codons will bind to the tRNA anticodon 5' GCU 3', considering wobble–base pairing rules. Select one:

a. 5' CGA 3'
b. 5' AGU 3' and 5' AGC 3'
c. 5' AGC 3'
d. 5' UGA 3' and 5' CGA 3'

Answers

Answer:

a. 5' CGA 3

Explanation:

The wobble type of base pairing also comprises the base pairs formed by inosine (I) also called hypoxanthine with Cytosine(C), Thyamine(T), or Adenine (A),

Where purine base pairs A to G(or I), A to A, and G to C.

Where

5' GCU 3' pairs with

5' CGA 3

Therefore G pairs to C, C pairs to G, U pairs with A.

Which statement describes competition in an environment? Organisms share a place to sleep. A living thing consumes berries on a tree. Sunlight shines only three months out of the year. A stream supplies an abundance of water in a forest.

Answers

Answer:

Sunlight shines only three months out of the year.

Explanation:

I think this is right

Because abundance means a large amount so there would be no competition there.

If organisms share a place to sleep then that means no competition

If a living thing is consuming berries on a tree then the living thing is just eating

But if the sunlight only shines three months out of the year then that can cause a shortage of food in the environment causing for the living creatures in the environment to compete for the food that is left since there won't be enough to supply for and abundance of living things.

The statement that describes competition in an environment is option B a living thing consumes berries on a tree. Thus, consuming berries on a tree is reducing the availability of the food for other livings depends on the berries.

What is survival of living things?

In the nature, the concept that survival of the fittest domintates. The organisms which are fit physically and are smart to gather food will survive in the nature otherwise they will extincts.

An ecological community is a collection of populations of at least two distinct species that interact both directly and indirectly in a specific geographic area. Within this community, diffrent organisms can be found .

Numerous ecological characteristics and functions, including nutrient cycling and food webs, are based on interactions between species. Depending on the evolutionary context and environmental factors that they take place in, these interactions can have a variety of different natures.

Because of this, ecological interactions between particular individuals and entire species are frequently difficult to identify and quantify and depend on their scale and context they face extinction. Hence, option B is correct.

To find more on environmental competition, refer here:

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What is the natural tendency of molecules to spread from an area of high concentration to an area of low concentration?

A.
Active transport

B.
Vesicle

C.
Passive transport

D.
Diffusion

Answers

Answer:

This concept is known as diffusion.  Diffusion is a passive process, as it requires no energy for it to occur.  In a cell, it is used as a method of passive transport since it requires no energy.

Explanation:

A P E X

Which codon is the code for the amino acid serine (Ser)?
Messenger
Second base in codon
RNA Codons
U
С
A
G
UUU
Phe
UCU
UAU
UGU U
UUC UCC UAC
Tyr
UGC
Cys
U
Ser
UUA 1
Leu
UCA UAA Stop UGA Stop A
UUG UCG UAG Stop UGG Trp G
CUU CCU CAUT CGU U
His
CUC ССС САС! CGC
Leu
Pro
CUA CCA CAA CGA
Gin
CUG CCG CAG CGG
AUU ACU AAU
As
AGU
Ser
AUC lle ACC
ААС! AGC
A
Thr
AUA ACA
AAA
Arg
AUG startet ACG AAG AGG
GUU
GCU
GAU
Asp
GGU
U
GUC GCC
GAC
GGC
G
Val
Ala
GUA
Gly
GCA
GAA
Glu
GGA
A
GUG GCG GAG
GGG
Arg
First base in codon
이이이이이드
Third base in codon
OPOCO POCO Blocos
Lys AGA
A. AGU
B. UGA
C. AGG
D. AGA
No

Answers

Answer:

four codon in mRNA sequence code for serine aminoacid.

Explanation:

UCA

UCG

UCC

UCU

these four codons code for aminoacid serine.

Predict what would happen if chemical energy is burned?
Energy is converted to mechanical energy.
The amount of chemical energy starts to decrease.
Energy is destroyed.
Sound energy can be created through an explosion.

Answers

Answer:

The amount of chemical energy starts to decrease.

Explanation:

Hope this helped

How does the phrase
division of labor relate to differentiation?

Answers

It relates because whither separate a long fast into more manageable steps.

ALOT OF POINTS MARKING POEPLE AS BRAINLIST

Look at the graph. Explain how the two population are related to each other

Answers

both species had growth in number within the same time period

both of the species population increased and decreased around the same times

Which list of countries arranged least to most in terms of how much of their income they spent on food
1China Canada Poland Kenya
2Poland China Kenya Canada
3 Canada Kenya Poland China
4 Canada Poland China Kenya

Answers

Answer:

is number three

Explanation:

Calculate the force needed to cause a 6 kg bowling ball to accelerate 20 m/s2.

Answers

Answer:

120N

Explanation:

F=ma

120N=6kg(20m/s^2)

Explain one way the water cyce affects weather.

Answers

Answer:Consequently, the temperature will fall. Rainfall and snow are results of water cycle and can lead to severe weather conditions. Excessive rainfall due to water cycle can cause floods. Extremely low rainfall, lack of adequate water sources can lead to draught in a given region.

Explanation:

How do healthy cell decide when to divide?​

Answers

Answer:

Cells regulate their division by communicating with each other using chemical signals from special proteins called cyclins. These signals act like switches to tell cells when to start dividing and later when to stop dividing.

A healthy cell decides when to divide by sensing and receiving signals from its surrounding environment.

The cell cycle can be divided into interphase and a mitotic (M) phase.

During the interphase, the cell synthesizes all materials required (i.e., proteins, DNA, etc) to divide during the M phase.

During the cell cycle, a cell modulates its division by communicating with other cells via specific chemical messenger molecules known as cyclins.

Cyclins are proteins that interact with Cyclin-dependent kinases (CDKs)  and thus function as molecular switches that regulate the progression through the cell cycle.

In conclusion, a healthy cell decides when to divide by sensing and receiving signals from its surrounding environment.

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Write a paragraph 4-5 sentences as to which one you think is better sexual or asexual reproduction

Answers

Answer:

Asexual

Explanation:

I think Asexual reproduction is better because you only need one reproduction Creature. For example plants, they are asexual so they do not need to worry about mating. Instead they can just create more plants by doing nothing. This helps us because we get more plants in a shorter amount of time. another example of Asexual reproduction is cross-pollination which is also an amazing way of creating more plants in a shorter time.

SOMEONE PLZ HELP ME!!!!!!!

Answers

Answer:

nucleus  mitochondria ,

, lysosome i think

Explanation:

Answer:

A) nucleus

B) mitochondria

D) lysosomes

Explanation:

you can look at a diagram and find the differences

Compare the exoskeletons of two invertebrates: a grasshopper (Arthropod) and a clam (Mollusca). How do they differ in relation to support and movement?

Answers

Answer:

Mollusca: Unsegmented exoskeleton, with no appendixes articulated to them. This skeleton has a calcareous origin. Arthropoda: Segmented exoskeleton, with different appendixes articulated to them, which develop different functions. This skeleton has a chitinous origin.

Explanation:

Clams are bivalves. Their calcareous exoskeleton has two valves dorsally articulated to each other. They do not articulate with any appendix, although. These animals also have a foot, a small head, and a developed mantle cavity. The valves are convex, oval, and unsegmented. They are composed of three layers: periostracum, prismatic, and pearly. En the dorsal portion of each valve, there is a bulge called the umbo, which is the oldest part of the valve. The articulation has some teeth-shaped structures that are intercalated, maintaining the valves together and fixed. Grasshoppers have a chitinous exoskeleton divided into three principal segments or regions that allow their movement: head, thorax, and abdomen. The head is orientated in such a manner that their feeding apparatus is heading down. Also, the head segment has composed eyes and antennae. The thorax is the medial region of the body. It has three segments: the prothorax, mesothorax, and metathorax. Each of these segments articulates with a pair of legs. Finally, the abdomen is composed of many segments that might reach up to 7 or 11.

What key adaptation allowed the ferns to be successful and populate more areas than the bryophytes?

Answers

Answer:

Possession of root, leaves and vascular/conducting tissues

Explanation:

Ferns and bryophytes are regarded as lower plants in botanical studies. Bryophytes have been in existence prior to the appearance of ferns. BRYOPHYTES are a group of non-vascular plants i.e. lack conducting tissues such as xylem, phloem etc. They include misses, liverworts and hornworts. Ferns, on the other hand, belong to a group of vascular plant species called PTERIDOPHYTES.

However, in terms of population and domination of the Earth, ferns are believed to be more successful than their counterparts (bryophytes). This is primarily because of the possession of true roots and vascular tissues like xylem (for conducting water), phloem (for conducting sugars) by FERNS making it easily adapted to life on land.

What should scientist do after completing a scientific investigation

Answers

Answer:

confirm the results if you're using edge

Explanation:

Answer:

B. confirm the results

Explanation:

i just took it

a flea and dog are a. example of

Answers

Answer:

Parasitism

Explanation:

A flea and a dog go with this example because a flea irritates the dogs skin and feeds on its blood. (Just like how some sea animals carry bacterial diseases. Like Shrimp or something)

Hope this helped xoxo! :)

Atoms of A decay to atoms of B with a half-life of 200,000 years. If there are 20,000 atoms of A to begin with, how long will it take for there to be 2,500 atoms of A?

Answers

Answer:

The correct answer is: 600,000 years

Explanation:

Half-life is the time which is essential or required to decrease a specific substance to half of its initial amount of the substance. So, if a substance has a half-life of 200,000 years then it means it takes 200,000 years to decrease or change into a new substance and remain half of its initial quantity.

half-life              amount

     0                  20000

     1                    10000          

     2                    5000

     3                     2500

total half-life = 3 to 2500 atoms of A

so, the time will be = 3 * 200,000 years

 = 6000000

If you multiply six positive numbers, the product sign will be

Answers

Answer:

Positive

Explanation:

Because there is no negative numbers in your equation and a positive times a positive equals a positive.

10.
_________produces pollens and______
develops into the fruit.

Answers

Answer:

stamen produces pollen ovules develops into fruit

Explanation:

In which of the following relationships do both species benefit?
A. Competition
B.Commensalism
C. Parasitism
D. Mutualism

Answers

D. mutualism is when both benefit
I’m pretty sure it’s D :)

ALOT OF POINTS MARKING POEPLE AS BRAINLIST

Look at the graph. Explain how the two population are related to each other

Answers

Look at the picture carefully so that means it’s the tallest ones

Which of the following is not a viral disease : (needed ASAP)

1. AIDS
2. Typhoid
3. Mumps
4. Polio ​

Answers

Answer:

It is typhoid. typhoid is not a viral disease

Answer:

Typhoid is not a viral disease.

Explanation:

Viral diseases are spread through virus particles, while typhoid is spread from typhi bacteria.

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