Answer:
chalk powder can be seaprated by dissolving with water
rice grains remain
stones by hand
Answer:
chalk with the machine and rest all with hands
Explanation:
Before a cell can divide it must copy one dna_____at a time in a process called DNA replication.
Answer:
DNA replication is the process by which a molecule of DNA is duplicated. When a cell divides, it must first duplicate its genome so that each daughter cell winds up with a complete set of chromosomes.
Explanation:
1. The histogram below shows the total estimated new breast cancer cases diagnosed in 2003.
Histogram
2. The results in this table below are from a 2007 study investigating BRCA mutations in women diagnosed with breast cancer. All of the women in the study had a family history of breast cancer.
BRCA Mutations in Women Diagnosed with Breast Cancer
BRCA1 mutation
BRCA2 mutation
No BRCA mutation
Total
Number of patients
89
35
318
442
Average age at diagnosis
43.9
46.2
50.4
Preventive mastectomy*
6
3
14
23
Preventive oophorectomy*
38
7
22
67
Number of deaths
16
1
21
38
Percent died
18
2.8
6.9
8.6
*A mastectomy is the surgical removal of one or both breasts, either partially or fully. An oophorectomy is the surgical removal of an ovary or ovaries.
Things to address in your summary essay:
Describe how mutations lead to genetic variations.
Which appears to be more dangerous: the BRC1 or BRC2 mutation?
Analyze a woman’s risk of dying of cancer if she carries a mutated BRC1 gene.
How do heredity and inheritance relate to the data presented in these charts?
What data would you need to see in order to draw conclusions about the effectiveness of preventive surgeries?
What does the age at diagnosis tell you about the mutation?
Explain how breast-cancer genes are still present in the population, despite cancer-related surgeries and deaths.
Answer:
Explanation:
Mutations are effectively errors in the DNA copying or transcription processes. They can occur naturally or be caused by mutagens, either chemical such as benzene or environmental such as ultraviolet light. These mutations concern the basses on DNA and can be as small as one base changing to another or as complex and detrimental as the insertion of a new base along the strand. Such mutations can drastically change the proteins created by an organism and affect entire chromosomes or genes. Some mutations that affect gametes can be passed down from parent to offspring and are called germline mutations. Such mutations can create entirely new alleles and increase a populations genetic variation. One such genetic mutation that occurs in humans in cancer. Cancers are errors in a cells DNA caused by mutations that allow the cell to grow and multiply uncontrollably copying the mutated DNA along the way. One specific type of cancer is breast cancer. Breast cancer has two different types of mutations. There are the BRCA 1 and 2 varieties. According to the charts, the BRCA 1 mutation appears to be more deadly. If a woman carries the BRCA 1 mutation, she has, once again according to the chart, an 18 percent chance of death. All of the women in the table above had a family history of cancer. This would point to the fact that cancer can be passed down as well as contracted from a certain type of mutagen known as a carcinogen. The table also references preventative surgeries in a number of women carrying both the BRCA 1 and 2 mutations as well as some without either. Unfortunately, given the data shown, it is impossible to determine the effectiveness of such procedures. To be able to judge this, data about the survival rates of women who underwent the procedures versus those who did not would be required. The bar graph above the chart also mentions ages. It shows that the numbers of cases of breast cancer increase rather quickly until ages 50-59 and then steadily and slowly decline. Most breast cancer cases occur in women 50-59 years old. This tells us that the mutation takes quite a few years to manifest as it is a genetic mutation and is furthered by the sufferers decreased ability to fight off carcinogens with age. If cancer can be removed by surgeries or by the death of the afflicted, why does it still exist in our population? The answer is simple. Cancer can be passed on hereditarily but that is not the only way for it to be contracted. Carcinogens that exist as chemicals or as environmental factors are present everywhere and can mutate one’s DNA and therefore genes. This can then be passed on to offspring as well.
Genetic variations occur as a result of recombination and mutation. Variations enable organisms to adapt to environmental conditions.
What do you mean by genetic variations?Genetic variations can arise from gene variants (also called mutations) or from a normal process in which genetic material is rearranged as a cell is getting ready to divide (known as genetic recombination).
The genetic diversity has three different sources: mutation, recombination and immigration of genes. Mutation is the driving force of genetic variation and evolution.
Genetic diversity is important because it gives species a better chance of survival. However, genetic diversity can be lost when populations get smaller and isolated, which decreases a species' ability to adapt and survive.
Learn more about genetic variations:
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O Biology is the science of exception, Justify it with
examples
Answer:
Biology deals with living organisms which show enormous variations and, therefore, numerous exceptions are found.
There are two reasons:
Each organism evolved in a different way to adapt to their environments the best way possible.
It is not really so. There are common rules to biology as in physics, but the problem is we study much more complex systems. More complexity results in more emergent properties, thus they appear to be exceptions.
Biology deals with living organisms which show enormous variations and, therefore, numerous exceptions are found.
justifying it with examples:
1. All living cells have a nucleus except mature red blood cells of mammals.
2. Red blood cells of all mammals are without nucleus except those of camel.
3. Stem is the part of plant above the ground but potato, corm and ginger are underground stems.
4. Blood of all vertebrates is red due to the presence of hemoglobin but a shark, Carcharhinus, has colorless blood.
by the above examples you can see that biology the science of exception.
Explanation:
What is the correct order of a food chain containing the following organisms: quail (bird), desert shrub, coyote, snake?
Answer:
desert shrub - quail - snake - coyote
Explanation:
the quail bird eats the desert shrub, the snake eats the quail, the coyote (a-pex predator in this chain) eats the snake.
The ____ likes to play a lot.
a. lion
b. gorilla
c. snake
d. monkey
Answer:
D
Explanation:
Its either a gorilla or monkey,but monkey sounds right.
Happy Thanksgiving ;D
Answer:
monkey
Explanation:
i’m very confused on this question so i rlly need help asap
Answer:
A tall, green plant with dominant alleles for both characteristics have a genotype TTGG and its phenotype is tall and green.
Explanation:
For a given trait, the dominant allele of the allelic pair is represented in capital letters (T and G), while the recessive allele is represented in small letters (t and g).
In the case of this plant, whose phenotype is tall and green —both dominant characteristics— and considered pure because both alleles are dominant, the genotype is TTGG.
In the case of a hybrid, the phenotype would be the same but the genotype would be TtGg. A recessive phenotype would be ttgg.where do the small molecules like water pass through the membrane?
Answer:
Water is transported across the membrane by the aquaporin (AQP) family of passive channels.
Explanation:
ok is that the answer you are looking for?
Why does chewing food speed up digestion? *
Bacteria in the food are killed.
O Foodis mixed with protease.
O The surface area of the food is increased.
O The taste of food is improved.
Students investigate how onion cells react to salt (NaCl) solutions of different concentrations. They observe onion cells in three salt solutions under a microscope.
The image of an onion cell in a 3% salt solution is shown.
Onion Cell in 3% Salt Solution
Answer:
Less than 3%
Explanation:
I'm guessing that since the solution has a concentration of less than 3%, the water would go into the cell to maintain which would make it expand.
Onions cells can react in different ways when place in any solution. The image of an onion cell are said to be:
The first image is greater than 3% The second image is greater than 3%.
When the salt water is added to the onion tissue, cytoplasm pulls away in course of time from the cell wall. So, due to that, water begins to leave the onion cell where it was more highly concentrated to the area where it was less concentrated.
Onion cell does not burst when placed in a hypotonic environment due to the fact that it has strong cell wall, which hinders the burst from taking place.
Onion peel often shrinks in salt solution when water from cells cytoplasm moves out of the cell.
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The respiratory system _____.
does not work with any other systems
removes carbon dioxide from the body
supplies the body with oxygen
includes the lungs
does not need blood to work
Answer:
Reacts to external environmental conditions and protects the body's deeper tissues; Includes skin, hair, nails, and sweat glands.
Explanation:
Answer:
2. Removes Carbon Dioxide from the body
3. Supplies the body with Oxygen
4. Includes the lungs
Explanation:
Hope it helped!
Which organ system is responsible for the movement of water, nutrients, sugar and gases throughout the body?
A. Nervous
B. Circulatory
C. Integumentary
Answer:
B. Circulatory
Explanation:
The nervous system controls and balances the five senses. The integumentary system is your hair, skin, and nails. That helps the body maintain homeostasis. The circulatory system carries nutrients, oxygen, and hormones to cells and gets rid of waste.
Explain two ways materials can enter the cell through passive transport. Include in your answer: the types of substance that is transported, the concentration gradient, and any structures in the cell membrane required to be used.
Explain two ways materials can enter the cell through passive transport. Include in your answer: the types of substance that is transported, the concentration gradient, and any structures in the cell membrane required to be used.
Answer:
Osmosis and facilitated diffusion are two forms of passive transport that are integral to cellular transport mechanisms.
Explanation:
Cells surrounded by a bilipid layer or plasma membrane are amphiphilic, with their polar, hydrophilic lipid heads facing outward, while their hydrophobic non-polar lipid tails facing each other inward.
Although lipid-soluble molecules travel quickly through the bilayer, traveling across its surface into the cell is often difficult for charged and large molecules. Thus, transport proteins, pores and gated channels, transmembrane channels, embedded within the membrane, help to preserve selective permeability.
Across plasma membranes as a form of passive transport in cells, substances move via:
osmosis - water molecules readily pass through the membrane; the molecules move from high concentration regions to low concentration regions at will through the membrane- they move down their concentration gradientfacilitated diffusion - channel proteins allow charged ions to move across the membrane. Sodium ions are able to pass freely through specialized sodium channel pores into some cells. These channels always remain open- the ions move down their concentration gradient.
14. Offspring of prey are more likely to be _because of predation. A. smaller in population size. better adapted to the environment C. eaten and causing the species to be on the verge of extinction. D nonexistent
Answer:
C. eaten and causing the species to be on the verge of extinction.
Explanation:
They are small, and easy to catch. A simple (but sad) meal if you ask me.
~PumpkinSPice1
What element is a component of almost all biological molecules (life)? What is the study of this branch of chemistry called?
Answer:
Caborn is essential to on Earth
Please help me if you help and get it right ill give you a brainy thing
Answer:
Ribosomes
Explanation:
HELP PLEASE ILL GIVE BRAINLIEST
Answer:
external
Explanation:
Through the process of photosynthesis, plants use the sun's energy to make sugars to function. External means from an outside force, while internal means from within. Since the sun isn't inside a plant, they gather it from outside, thus it's external.
A J-shaped curve is called a(n) _______. a. logistic growth curve b. exponential growth curve c. linear growth curve d. population growth curve
Answer:
b exponentail growth curve
Explanation:
just took the test
Answer:
BExplanation:
is the answer.
What is insulin and why do people with Type 1 diabetes need it to survive?
Answer:
Insulin is needed to move blood sugar (glucose) into cells. Inside the cells, glucose is stored and later used for energy. With type 1 diabetes, beta cells produce little or no insulin.
PLEASE HELP! Need this today ASAP!
Seismograms record the forces of earthquakes. How do these seismograms help scientists learn about the composition of the Earth?
(My teacher asks for a minimum of 5 sentences)
Explanation:
Earthquake waves produces two very important waves that useful in studying the composition of the earth.
These waves are P and S-waves.
P-waves are primary longitudinal waves that propagates through any material medium. S-waves are secondary transverse waves that can only pass through solids but not fluids.Using these waves we can know the composition of the earth.
Representative organism Type of symmetry (Radial, Bilateral, or None) Type of skeleton (ENdoskeleton, EXoskeleton, or None) Type of appendages (Jointed, Not Jointed, or Absent) Segmentation (Present or Absent)
Sponges
Cnidarians
Roundworms
Annelids
Mollusks
Arthropods
Echinoderms
Vertebrates
Answer:
Sponge; Radial Symmetry; Endoskeleton; Absent Appendages; Absent Segmentation
Cnidarians; Radial Symmetry; No Skeleton; Non-Jointed Appendages; Absent Segmentation
Roundworms; Radial Symmetry; No skeleton; Absent Appendages; Absent Segmentation
Annelids; Radial Symmetry; No skeleton; Absent Appendages; Present Segmentation
Mollusks; Bilateral Symmetry; Exoskeleton; Non-Jointed Appendages; Absent Segmentation
Arthropods; Bilateral Symmetry; Exoskeleton; Jointed Appendages; Present Segmentation
Echinoderms; Bilateral Symmetry; Endoskeleton; Non-Jointed Appendages; Absent Segmentation
Vertebrates; Bilateral Symmetry; Endoskeleton; Jointed Appendages; Absent Segmentation
which of the following characteristics is true about an organism whose remains formed a good index fossil.
a.) it must be unique orgsnism
b.) it must be an organism that lived all around the world
c.) it must be an organism that lived for a very short time period
d.) all of these characters are important fo an index fossil
Answer:
d.) all of these characters are important fo an index fossil
Explanation:
Organisms have the characteristics to die and their remains form fossils. A fossil is a preserved remain of a previously living organism. Index fossils are fossils used to tell us more about a particular period. However, before the fossil remains of an organism can be used for this purpose, it must have specific characteristics including the following:
- It must be a unique/distinct species
- It must be geographically abundant
- It must live only a short period of time
Based on these above characteristics of a good index fossil, an organism whose remains must form a good index fossil must possess ALL THE MENTIONED CHARACTERISTICS MENTIONED IN THE OPTIONS.
Answer:
d
Explanation:
Index fossils have to be unique and abundant to be easily identified, abundant means it must be around the world. Index fossils usually live for a short period of time. So D is the correct answer.
Scientists are trying to prevent some genetic diseases by studying and learning how to ____________ them
Answer:
treat or control
14. Which of the following correctly lists the levels in an ecosystem from largest to smallest?
a. Ecosystem, community, population, individual
b. Community, ecosystem, population, individual
C. Population, ecosystem, individual, community
d. Ecosystem, population, community, individual
Answer:
(a) Ecosystem, community, population, individual
is right answer I think
Choose from: Art & Music, Making Clothing, Recording Information, Burial, Carrying & Storing, Hearths & Shelters, Stone Tools, Getting Food, Primate Behavior, & Footprints. What are 3 things you learned
Answer:
I learned from recording information
always listen attentively never slack offmake sure to take notes accordinglyWhat is the autotroph and herotroph for photosynthesis
HELP ASAP!!
Which of the two processes, photosynthesis or cellular respiration, is exergonic or endergonic?
Which process involves mitosis and is used to produce new mushrooms or mold.
A. binary fission
B. sporulation
C. vegetative propagation
D. budding
Answer:
B
Explanation:
brain pls
Create an example in which a mutation entered the gene pool and due to predator pressure. Becomes predominate. For example, think about how the color of the Peppered moths during the industrial revolution changed. The moths were light in color, but due to all the pollution from industry the trees they lived on turned dark making the light moths an easy target for birds. The moths with the mutation for dark color were able to blend with the darker bark and survived. These dark colored moths passed their genes on to their offspring and over a relatively short period of time most of the moths became dark. When the pollution decreased, the lighter colored moths predominated once again.
*Write a paragraph or so it can be a little under. Ill give you brainiest.*
Answer:
The population of light colour Peppered moths decreases and dark Peppered moths increases.
Explanation:
During the industrial revolution, the population of light colour Peppered moths decreases and dark Peppered moths increases because due to industrial revolution, air pollution increases which spreads a black dust on the trees and as a result the light colour Peppered moths can easily be seen in the dark by its predator and feed on them while dark colour Peppered moths can't be seen in the dark so the predator is unable to feed and as a result the population of dark colour Peppered moths increases.
Your neighbour wants to get a Christmas tree for decoration but has difficulty distinguishing between a Conifer and Bryophyte. Give THREE characteristics to help your neighbour to choose the right tree for her decoration.
Answer:
Three characteristics of conifer tree
(1) the leaves of conifer trees resemble niddles
(2) the leaves provide the key to identifying conifer trees
(3) conifer trees do not produce flowers
Three characteristics of Bryophyte
(1) Bryophyte is also called Amphibians of plant kingdom
(2) Their sporophytes are unbranched
(3) Dicotomous branching
How are two organisms who descend from the same common ancestor related?
a.)geographically
b) slightly
c) distantly
d) closely
Answer:
d i think, Hope this helped.
Explanation:
Answer:D
Explanation: