What must be true for natural selection to happen?
A. There can be no competition for resources
B. There must be genetic variation in the population.
C. All organisms must reproduce the same amount.
O D. The population must be below carrying capacity.
Answer:
B
Explanation:
There must be genetic variation in the population.
ở một loài thực vật, xét 2 cặp gen phân li độc lập A,a và B, b, mỗi gen quy định 1 tính trạng, alen trội là trội hoàn toàn. Tiến hành mmotj phép lai giữa hai cây, thu được F1. Thep lý thuyết, kiểu hình mang hai tính trạng trội ở F1 không thể chiếm tỷ lệ:
A: 12,5% B: 37,5%
Watershed drains waters into a stream and tributaries. Which is its main function?
A. Production of continuous water supply that maintains life forms
B. Prevents growth of new plant species
C. Contributes to soil formation
D. Creates new minerals
Answer:
B. Prevents growth of new plant species.
Answer:
B. Prevents growth of new plant species
4. The inner membrane of the mitochondria is impermeable to ions. How does this fit with what
you've learned about membrane structure? Why is this important to cellular respiration?
Answer:
The inner mitochondrial membrane contains proteins involved in the electron transport chain. This chain releases energy that is then used to generate an electrochemical gradient, which is subsequently used to synthesize ATP
Explanation:
Mitochondria are membrane-bound organelles that have an inner membrane separated from an outer membrane by the intermembrane space. Moreover, the mitochondrial matrix is located within the inner membrane. The inner mitochondrial membrane contains proteins involved in the electron transport chain and ATP synthesis. Oxidative phosphorylation (electron transport chain) is the third stage of cellular respiration in aerobic organisms in which ATP is generated by transferring electrons from NADH or FADH2 to O2 by a series of electron carriers located in the inner mitochondrial membrane. The trans-membrane complexes of electron carriers are multiprotein enzyme complexes (I–V) and electron carriers (i.e., coenzyme Q10 and cytochrome c) required for the communication between complexes. The electron transport chain is coupled to proton transfer from the matrix out to the intermembrane space, thereby generating a proton gradient which is then used by ATP synthases to synthesize ATP.
How do plant cells that do not have chlorophyll get food?
Answer:
All plants cells have chlorophyll so there is no problem
animal modified for climbing are called
Record the disorder revealed in the karyotype below.
I need help
Answer:
i don't have that alien eys
you do have
in one word this photo is not clear for my eyes
[tex]1 \sqrt{ \frac{ \frac{24 \frac{ \frac{21150 \sqrt{ \cot( \alpha ) } }{?} }{?} \times \frac{?}{?} \times \frac{?}{?} }{?} }{?} } [/tex]
Please help!! Im gussing it’s either Y or Z
Answer:
The answer is Y
Explanation:
Trust me I've done this before
số lượng protein thu được là bao nhiêu nếu tổng hợp phân tử protein chứa 100aa, trong mỗi phân tử đều chứa 20aa khác nhau
Explanation:
feg3fegrgt✴☝️☝️☝️☝️⛲
Answer:
protein number of collect is a bao nhiêu nếu protein phân tử tổng hợp chứa 100aa, trong mỗi phân tử đều chứa 20aa khác nhau
Explanation:
->1 phân tử chứa đủ 20 aa vậy ta cần 5 protein để tổng hộp thành 100aa
What are the two layers of the skin and the 1 layer below the skin?
What is the answer for this
Answer:
Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere. Animals and plants need to get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned.
Which factors improve soil fertility? Select the three correct answers.
A. Nitrogen
B. Humus
C. Manure
D. Horizons
E. Bedrock
Which effect would you expect a Species Survival Plan to have on the crested
toad population in Puerto Rico?
A. Scientists reintroducing crested toads into the wild
B. Most of the crested toads dying out
C. Invasive species outcompeting crested toads in the wild
D. Most of the crested toad habitat being destroyed
SUBMIT
The correct answer is A. Scientists reintroducing crested toads into the wild.
Explanation
Species Survival Plan is a conservation program promoted by conservationists and zoologists that specializes in those animals that are near extinct, endangered, or threatened. This program mainly aims to breed these species in captivity to ensure their future preservation and reintroduction to nature. According to the above, the effect that could be expected from the implementation of the Species Survival Plan in Puerto Rico with the crested toads would be the reintroduction of this species into the wild after being bred in captivity.
5. Which function is associated with phagocytes in the blood?
O A) initiating blood clots
B) transporting dissolved nutrients
O C) producing antibodies
D) engulfing bacteria
Answer:
D) Engulfing Bacteria
Explanation:
Which type of RNA functions as the location where proteins are made? mRNA rRNA tRNA siRNA
The type of RNA that functions as the location where proteins are made would be the rRNA.
rRNAs are known as ribosomal RNAs. They are usually found associated with the ribosome - the organelles responsible for synthesizing proteins in eukaryotic cells.
mRNA is the messenger RNA. They are formed directly from the transcription of DNA in the nucleus and then transported to the cytoplasm. They carry genetic information in coded forms and the codes are translated protein synthesis.
tRNA is the transfer RNA. It carries amino acids and anticodons.
siRNA are small interfering RNA.
More on the RNAs can be found here: https://brainly.com/question/19815744
function of semilunar valves in the heart
Answer: They close to prevent blood from flowing back into the ventricles.
Explanation: To find the semilunar valve is the valve between the left ventricle and the aorta is the aortic semilunar valve.
Suc- strains cannot utilize sucrose, trp- strains cannot synthesize tryptophan. In the generalized transduction of a suc-trp- strain of E. coli using bacteriophage derived from a suc+trp+ cell, what medium would select for suc+ and trp+?
A) a minimal medium
B) a minimal medium + sucrose
C) a minimal medium + tryptophan
D) a minimal medium + sucrose + tryptophan
E) none of the above
Answer:
B) a minimal medium + sucrose
Explanation:
Suc+ ⇒ can utilize sucrose, so you have to add sucrose to the medium.
Trp+ ⇒ can synthesize tryptophan, so it is not required to add tryptophan to the medium because the cell can produce it.
According to this, to select for suc+ trp+ you have to only add sucrose to the medium. Thus, it will only grow the cells that can utilize sucrose and can synthesize tryptophan.
Therefore, the correct option is: B) a minimal medium + sucrose
Proteus vulgaris has a doubling time of roughly 28 minutes. If an initial population of 500 cells is allowed to grow for 6 hours in ideal conditions, what will be the final population? Use three significant figures for your final answer.
Answer: The final population of Proteus vulgaris after 6 hours is [tex]3.71\times 10^{6}cells[/tex]
Explanation:
We are given:
Proteus vulgaris divides and doubles every 28 minutes
Total time given = 6 hours = 360 min (Conversion factor: 1 hr = 60 min)
Number of times Proteus vulgaris doubles in 6 hours = [tex]\frac{360min}{28min}=12.857times[/tex]
Calculating the number of bacteria after 6 hours under ideal conditions:
We are given:
Initial population = 500 cells
Number of times it doubles = 12.857 times
Final Proteus vulgaris population = [tex]500\times 2^{12.857}=3709476.8=3.71\times 10^{6}cells[/tex]
Hence, the final population of Proteus vulgaris after 6 hours is [tex]3.71\times 10^{6}cells[/tex]
High blood pressure may lead to strokes and heart attacks and is a risk factor that may be changed by taking medication?
Answer:
Yes
Explanation:
High blood pressure can be redused, but can't stop permanently.
Complete each statement by using the appropriate word or phrase from the list. Then place the statements in the order of an action potential repolarization event.
1. Through the activated channels, _________ now flows outwards causing the membrane to repolarize back towards RMP.
2. As the membrane potential ___________, the voltage-regulated sodium channels begin closing which in turn reduces the sodium movement to the ICF
3. With a larger duration of activation than sodium channels, the potassium channels allow for a greater movement of potassium to the ECF causing a short period of_______.
4. With membrane potentials approaching +35 mV, the _________channels become fully activated.
a. Sodium
b. Voltage regulate sodium
c. Potassium
d. Rises towards zero
e. Hyperpolarization
f. Voltage regulated potassium
Answer:
1. Potassium
2. increasing towards zero
3. hyperpolarization
4. voltage-regulated Potassium
Explanation:
Membrane potential can be defined as the difference in electric charges inside and outside of a cell. The resting membrane potential (RMP) occurs when there is no net current across the membrane and therefore the cell is in a non-excited state. At the RMP, sodium ions (Na+) are more concentrated inside the extracellular fluid (ECF) than inside the intracellular fluid (ICF), while potassium ions (K+) are more concentrated inside the ICF. The diffusion of K+ outside the cell triggers its hyperpolarization, by becoming the membrane potential more negative compared to the resting potential. As the potential nears +35 mV, the voltage-regulated potassium channels are open, thereby K+ ions leave the cell down its concentration gradient, while voltage-gated Na+ channels become saturated and inactivate.
9. What is the relationship between natural selection and evolution?
Answer:
Through this process of natural selection, favorable traits are transmitted through generations. Natural selection can lead to speciation, where one species gives rise to a new and distinctly different species. It is one of the processes that drives evolution and helps to explain the diversity of life on Earth.
Explanation:
Molecules produced in the nucleus are transported to the cytoplasm via?
Answer:
Molecules produced in the nucleus are transported to the cytoplasm via endoplasmic reticulum.
five characteristics of harmattan
The Harmattan is a season in West Africa, which occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara Desert over West Africa into the Gulf of Guinea.[1] The name is related to the word haramata in the Twi language.[2] The temperature is cold in most places, but can also be hot in certain places, depending on local circumstances.[3]
The Harmattan is a season in West Africa, which occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara Desert over West Africa into the Gulf of Guinea.[1] The name is related to the word haramata in the Twi language.[2] The temperature is cold in most places, but can also be hot in certain places, depending on local circumstances.[3]Harmattan haze surrounding Abuja National Mosque in Abuja
The Harmattan is a season in West Africa, which occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara Desert over West Africa into the Gulf of Guinea.[1] The name is related to the word haramata in the Twi language.[2] The temperature is cold in most places, but can also be hot in certain places, depending on local circumstances.[3]Harmattan haze surrounding Abuja National Mosque in AbujaThe Harmattan blows during the dry season, which occurs during the months with the lowest sun. In this season the subtropical ridge of high pressure stays over the central Sahara Desert and the low-pressure Intertropical Convergence Zone (ITCZ) stays over the Gulf of Guinea. On its passage over the Sahara, the harmattan picks up fine dust and sand particles (between 0.5 and 10 microns). It is also known as the "doctor wind", because of its invigorating dryness compared with humid tropical air.
Explanation:
Harmattan is a season in west Africa.
The Earth and the moon are kept in orbit by gravity and mass. Please select the best answer from the choices provided T F
Answer:
True
Explanation:
the Earth and the Moon are kept in orbit by gravity and mass.
Answer:
True (T)
Explanation:
Yeah, the Earth and the moon are kept in orbit by gravity and mass. Hence, this statement is True (correct).
What is the 'processor of thermoregulation that determines if a change in
body temperature is needed?
A. Thyroid
B. Pancreas
C. Kidneys
D. Hypothalamus
Answer:
D) Hypothalamus
Explanation:
Which of the following is true about evaluating an experiment?
A)Evaluating an experiment allows the investigator to find errors and make improvements.
B)Evaluating an experiment is not important or required.
C)Evaluating an experiment can change the prediction.
D)Evaluating an experiment can make it more confusing.
Answer:
The correct answer is - A) Evaluating an experiment allows the investigator to find errors and make improvements.
Explanation:
Evaluation is the process in any experiment that helps in improving the analysis and remove missing components and errors to get better results. It also checks if all the process is included and running properly without error.
One should constantly be evaluating his or her experiment. It includes assessing how the experiment is going as you carry it out, what could have been improved if it was to be carried out again and how can eliminate any erros.
Reactants definition
DNA is transcribed into RNA, then RNA is translated into amino acids we can build into proteins
DNA contains four types of nitrogenous bases .One of these bases is -
Answer:
adenine (A), cytosine (C), guanine (G), and thymine (T)
Question 3 of 10
What is the next step in the scientific method, following stating a question?
A. Analyzing the data
B. Forming a hypothesis
C. Collecting the data
Answer:
B. Forming a hypothesis
Explanation:
Once you have a question in mind, you form a hypothesis (which is sort of an educated guess of what you expect or do not expect to happen) and then finally you can start on scientific investigations of collecting data and end with analyzing data and showing conclusion.
Answer:
the correct answer is B
Explanation:
because you always try to understand your question after you state it