The mass extinctions that occurred 250 million years ago and 65 million years ago may have been due to gradual processes or _____.
A.)a large comet or asteroid striking Earth

B.)widespread reproductive isolation

C.)lightning strikes

D.)rapid continental drift

Answers

Answer 1
A:a large comet or asteroid striking earth

Related Questions

What are the raw materials needed for cellular respiration?

A. carbon dioxide and glucose

B. water and carbon dioxide

C. sugar (glucose) and oxygen

Answers

Answer:

C. sugar (glucose) and oxygen

Explanation:

The sugar (glucose) and oxygen are the main raw materials involved in the cellular respiration process.

1.DNA is a molecule composed of two chains in form a ____________ compose by______________, ____________ and pentose. And the structure and function of genes.

Answers

Answer:

DNA is a molecule composed of two chains in form of a DOUBLE HELIX compose by ORGANIC NITROGEN CONTAINING BASE, PHOSPHATE GROUPS and PENTOSE.

Explanation:

Nucleic acids are found in all living cells. They are composed of strands made up of repeating units called nucleotides. Each nucleotide consists of

--> a five carbon sugar( PENTOSE)

--> a phosphate group

--> an organic nitrogen containing base: adenine, guanine, cytosine or thymine.

The two types of nucleic acids include:

--> Deoxyribonucleic acid ( DNA) and

--> Ribonucleic acid ( RNA)

Deoxyribonucleic acid ( DNA) is found in chromosomes located in the nucleus of cells.

STRUCTURE OF DNA

The DNA molecule consists of two strands that curve spirally to form a double helix structure. The strands are held together by hydrogen bonds between the base side arms. Each base on one strand will only pair with a specific base on the other strand: hence guanine will only pair with cytosine and adenine with thymine.

FUNCTIONS OF DNA

It stores the organism's hereditary traits and directs the day to day metabolic activities of each cell in the organism.

A mutation that can be inherited by offspring would result from A) random breakage of chromosomes in the nucleus of liver cells B) a DNA base substitution in gametes during meiosis C) abnormal lung cells produced by toxins in smoke D) sun exposure of skin cells

Answers

Answer:

B) a DNA base substitution in gametes during meiosis

Explanation:

Tobacco smoke contains carbon monoxide. What problem does this cause?
1 point
A)The carbon monoxide irritates the airways, causing bronchitis
B) The carbon monoxide combines with haemoglobin in the red cells, reducing the ability of the blood to carry oxygen
C) The carbon monoxide causes lung cancer
D) The carbon monoxide causes the blockage to the bronchi​

Answers

Answer:

B

Explanation:

It directly enters the bloodstream and displaces oxygen in red blood cells.

Biodiversity is important to human society because it *

Answers

Answer:

Biodiveristy is important to humans because it provides a good functioning ecosystem that supply oxygen, clean air and water, pollination of plants, pest control, wastewater treatment and many ecosystem services.

Explanation:

Question 7 (1 point)
In which organelle does DNA replication take place?
a
lysosome
mitochondria
nucleus
ribosome

Answers

The answer should be nucleus

1 point
Vhich of the following is an example of cohesion?
hydrogen bonding

water attracted to the side of a glass tube

water droplets attached to a spider web

water forming raindrops

Answers

Answer:

water forming raindrops

The respiratory system involves the intake of carbon dioxide into the body and the release of oxygen from the body.

A. True

B. False

Answers

Answer:

The answer is false, we intake oxygen and exhale carbon dioxide

Explanation:

Answer:

Hi, there the answer false

Explanation:

which examples represent abiotic factors affecting biotic factors? Check all that apply

Answers

Answer:

ash from a volcanic eruption kills new plant growth.

warm water from a nuclear power plant causes overgrowth of algae.

a river floods and deposits tree pollen along its banks.​

Explanation:

Ecosystem consist of biotic and abiotic elements. Biotic refers to all living organisms while abiotic refers to all non-living elements of the environment. Living organisms depends on abiotic factors such as light, temperature, water and soil etc for their growth and survival. In the above answer, Ash of volcano, warm water and rivers are abiotic elements while plant, algae and pollen are biotic elements.

Which is an example of a vestigial structure?

A) The flipper of a whale
B) The wings of a bird
C) The tailbone of a human
D) The eyes of a bat

Answers

Answer:

C) the tailbone of a human

Humans no longer have tails due to evolution because we don't need them. The other answers are body parts that are useful to those animals.

Hope this helps!

Which is not true of selective breeding?
Selective breeding always produces unhealthy
offspring
Selective breeding can be used to weed out weak
genes.
Selective breeding can be used to pass on
desirable genes.
Selective breeding has been used by humans for
thousands of years.

Answers

Answer:

selective breeding always produces unhealthy offspring

Explanation:

false becasue its mostly healthy and dominant genes

Drag each tile to the correct location.
Identify which questions can be answered through science and which cannot.

Is it right or wrong to use genetic
engineering to produce new food
products?

What are the most common social
settings that tend to produce
accomplished artists?

Do the types of organisms found in
the fossil record appear in consistent
sequences in different parts of
the world?

If a new gene is added to the genome
of a tomato species, will that species
be more resistant to insects?

Are Michelangelo's paintings more
impressive than Rembrandt's?

Should humans use biotechnology
to bring extinct organisms from the

Answers

Answer:

What can be awnsered by science are question 1,3, and 4 (Going top from bottom). The rest cannot be answered by science. ((I'm not 100% but I'm pretty confident)))

The hard outer covering of a snail's ventral foot is called the

Answers

Answer:

the operculum.

hope this helps :-)

What does the theory of evolution tell us about living things?

A) The environment can make them change rapidly over a short period of time. B)They create fossils when they die
C)Their environment makes them change slowly over time.
D)They can give us clues about extinct species. (science 7th grade) (100 POINTS)

Answers

Answer:

Their environment makes them change slowly over time

Explanation: I took the test and got it correct.

The agents of wethering erosion deposition and the rock cycle will slowly change the fossils over time. They may damage them or burry them deep into the layers of earth. Over time, as they age, new landforms will me made ontop of them. This is why they use the fossils to determine the age of the land. I hope this helps :)

Wasp stings are alkaline. Which substance would help relieve this injury?
A) Vinegar
B) Toothpaste
C) Tap water
D) Ammonia based window cleaner

Answers

Answer:

A

Explanation:

because is a good solution for injuries

i would say to relieve the pain you would want to neutralize it. so since its alkaline the answer should be an acid. c is neutral so mo. d is very alkaline so no. b i have no idea but a is very acidic. so i would go with a because it is the most acidic

What phase of mitosis is shown in the diagram below?

Answers

Answer: Its A. Prohase

Explanation:

Answer:

A . it's the prophase

Explanation:

prophase is the phase of mitosis in the diagram

1. What is facial reconstruction? Why is it used?

Answers

Answer:

Facial reconstruction is when you examine the bones of your face to figure out changes to make.

What is the complementary mRNA sequence of this DNA sequence?
DNA sequence: TAC

Answers

AUG

The opposite of T is A
The opposite of A is T but T is not in mRNA and is instead replaced with U
The opposite of C is G
I hope this helped :)

What is passive smoker ?​

Answers

Answer:

hope it helps you

Explanation:

efarBfshdynsbzbts6y ucCuffuyndUmYN5cxhmyfz7g8U

Second hand smoker hope this helped

Identify the gases obtained at cathode and anode during this process

Answers

The gas which is released at cathode is hydrogen, H2 and the gas released at anode is oxygen, O2. ... Therefore after electrolysis the water volume of one gas collected at one electrode is double (hydrogen gas) of anode (oxygen gas).

How do you calculate the number of neutrons?
A. The same as the atomic number

B. Equal to the number of protons

C. Equal to the number of elections

D. Take the mass number and subtract out the atomic number

Answers

Answer:

D

Explanation:

D is correct take the mass number and subtract it

Answer:

D. Take the mass number and subtract out the atomic number

Explanation:

We should take the mass number and subtract out the atomic number to calculate the number of neutrons.

Why is phosphorus a limiting growth factor in terrestrial ecosystems?

Answers

Answer:

Because the quantities of phosphorus in soil are generally small, it is often the limiting factor for plant growth. ... Phosphates are also limiting factors for plant-growth in marine ecosystems, because they are not very water-soluble. Animals absorb phosphates by eating plants or plant-eating animals.

have a good day

#BRAINLEST

Phosphorus is a limiting growth factor in terrestrial ecosystems because the quantity of phosphorus in soil are generally small it is often the limiting factor for plant growth.

What is the use of phosphorus in ecosystem?

Phosphorus-based fertilizers boost the growth of plants on land, phosphorus in the ocean increase the production of microbes and small marine plants called phytoplankton, which compose the base of the marine food chain.

Phosphorus, like nitrogen, is a critical nutrient required for all life. The most common form of phosphorus used by biological organisms is phosphate (PO4), which plays major roles in the formation of DNA, cellular energy, and cell membranes (and plant cell walls). Phosphorus is a common component in commercial fertilizers.

We can say that phosphorus are very important factor for plant-growth in marine ecosystems because they are not soluble in water.

Therefore, Phosphorus is a limiting growth factor in terrestrial ecosystems because the quantity of phosphorus in soil are generally small it is often the limiting factor for plant growth.

Learn more about phosphorous here:

https://brainly.com/question/16044323

#SPJ2

Help meeeeee plsssss! :)

Answers

D.
We have established an independent variable and a control group.

In a population:
A. Are organisms that live all over the world

B. Are autotrophs

C. All organisms are of different species

D. All organisms are the same species

Answers

Answer:

D. All organisms are the same species

Explanation:

The organisms of the same species in a particular area is called population.

which of the following is an abiotic factor?
A. Predation
B. Rainfall
C. Cropping
D. Grazing
E. Migration​

Answers

Answer: The answer is B. Rainfall

Explanation:

Good luck and hope this helps :)

B. Rainfall is an abiotic factor

The bacteria moves to areas of high oxygen concentration. Which process in the cell causes the bacteria to form these groups.

Answers

Answer: photosynthesis

Explanation: This is because it is a plant cell due to it having chloroplast

What is the function of the stigma?
A. To catch pollen grains

B. To produce eggs

C. To attract insects

Answers

Explanation:

A. to catch pollen grains

is yr correct ans.

hope it helps

stay safe healthy and happy..

Answer:

A. To catch pollen grains

Explanation:

The function of the stigma is to catch the pollen grains.

What is ecological succession?
A. Change that happens over time in an ecological community

B. A way a life

C. One person giving another person power

Answers

Answer:

A. Change that happens over time in an ecological community

Explanation:

Ecological succession is the change that happens over time in an ecological community. So, option (A) is the answer.

Answer:

A. Change that happens over time in an ecological community

Explanation:

Ecological succession is the gradual process by which ecosystems change and develop over time. Nothing remains the same and habitats are constantly changing.

There are two main types of succession, primary and secondary.

Primary succession is the series of community changes which occur on an entirely new habitat which has never been colonized before. For example, a newly quarried rock face or sand dunes.

Secondary succession is the series of community changes which take place on a previously colonized, but disturbed or damaged habitat. For example, after felling trees in a woodland, land clearance or a fire.

Loni makes a diagram to help organize what she has learned about the gas laws.


Which label belongs in the region marked X?

involves changes in temperature
has a constant volume
shows an inversely proportional relationship
does not describe pressure changes

Answers

Answer:

Shows an inversely proportional relationship.

Explanation:

The Boyle's law belongs in the region marked X whereas the other circle belongs to Charles law. There is inverse relationship between the two circles or these two laws because in Boyle's law, temperature is constant while on the other hand, in Charles law pressure is constant instead of temperature. In Boyle's law, pressure of a gas is inversely with its volume whereas in Charles law, the volume of a gas is directly proportional to its absolute (Kelvin) temperature.

chlorophll absorbs what colors

Answers

Answer: Violet and orange

Explanation:

They absorb light of other wavelengths with less intensity.

Other Questions
Suppose that 3 balls will be randomly put into 3 buckets, with each ball being equally likely to be put into each of the buckets, independently of which buckets are chosen for any of the other balls. (E.g., the first ball is equally likely to be put into any of the 3 buckets, and then regardless of which bucket the first ball is placed in, the second ball is equally likely to be put into any of the 3 buckets.) What is the probability that all of the balls will be put into the same bucket Why was Fern upset now that there was so many people in the barn? you attended an interview for a bursary to study towards your dream careerwrite out a two diary entries expressing your feelings before and after the interview What are the messing forces that would make the object be in equilibrium? which increases the rate of speciation?A. Gene flow increases B. Geographic isolation occurs C. Offspring disperse efficiently D. Organisms reproduce asexually find the number whose product with 2/211 gives 8/11 The arrest of Elizabeth Proctor for witchcraft at the end of Act II is an example of which element? A. Climax B. Motif C. Exposition D. Cliffhanger Find the equation of the least squares regression line. Show all calculations, and be sure to define any variables used. What is 30 rounded to the nearest whole number percent? can someone please help me!!!! Witch two chemists organized the elements based on properties suck as how the elements reacts or whether they are solid or liquid Alex is planning to surround his pool ABCD with a single line of tiles. How many units of tile will he need to surround his pool? Round your answer to the nearest hundredth.Answers: 8.9610.4813.4220.42 Select all the correct imagesSelect the atoms that belong to the same element With regards to the three levels of prevention/ intervention: _____________________ prevention minimizes the severity of the disease or injury once it has occurred. This can include health screenings such as mammograms, and colonoscopies for those in the appropriate age/risk category. Which of these events were effects of the Homestead Act? Check all of the boxes that apply. Example 3:In how many ways can a supermarket manager display 5 brands of cerealsin 3 spaces on a shelf?Solution: BEING TIMED! 10 pointsIn what ways can Washington voters participate in direct democracy? Check all that apply. MULTI CHOICEby being public servantsby creating initiativesby participating in protestsby running for public officeby voting in recall electionsby voting in referendums Which of these building materials is a renewable resource?A. Stainless steelB. BambooC. GraniteD. Limestone A colony contains 1500 bacteria. The population increases at a rate of 115% each hour. If x represents the number of hours elapsed, which function represents the scenario?f(x) = 1500(1.15)x f(x) = 1500(115)xf(x) = 1500(2.15)xf(x) = 1500(215)x Jalen says that the height, radius, and diameter of a cone lie entirely on the base of the cone. What is Jalens error?The height does not lie on the base because it is perpendicular to the base.The radius does not lie on the base because it contains the center of the base.The diameter does not lie on the base because it contains a radius of the circle.The base does not contain the height, the radius, or the diameter because it is a circle.