Answer:
2.6 billion years
Explanation:
There are essentially two ways of solving nuclear half-life problems. One way is by applying the half-life formula, which is
A
(
t
)
=
A
0
(
t
)
⋅
(
1
2
)
t
t
1
2
, where
A
(
t
)
- the quantity that remains and has not yet decayed after a time t;
A
0
(
t
)
- the initial quantity of the substance that will decay;
t
1
2
- the half-life of the decaying quantity;
In this case, the rock contains
1/4th
of the orignal amount of potassium-40, which means
A
(
t
)
will be equal to
A
0
(
t
)
4
. Plug this into the equation above and you'll get
A
0
(
t
)
4
=
A
0
(
t
)
⋅
(
1
2
)
t
t
1
2
, or
1
4
=
(
1
2
)
t
t
1
2
This means that
t
t
1
2
=
2
, since
1
4
=
(
1
2
)
2
.
Therefore,
t
=
2
⋅
t
1
2
=
2
⋅
1.3 = 2.6 billion years
A quicker way to solve this problem is by recognizing that the initial amount of the substance you have is halved with the passing of each half-life, or
t
1
2
.
This means that you'll get
A
=
A
0
2
after the first 1.3 billion years
A
=
A
0
4
after another 1.3 billion years, or
2
⋅
1.3 billion
A
=
A
0
8
after another 1.3 billion years, or
2
⋅
(
2
⋅
1.3 billion
)
Which action involves mixing soil with organic materials to improve soil quality?
A.
crop rotation
B.
conservation
C.
composting
D.
terracing
C. composting
it is the process of mixing of biodegradable organic material to the soil to inc the soil fertility
What is the most interesting
Or surprising thing you learned about the universe and galaxies?
Which one is warmer a normal year or El nino year?
2. Why is this change in global temperature a concern
Which statement describes the energy involved in diffusion?
Diffusion requires energy in all cases.
Diffusion requires energy only to move material in through the cell membrane.
Diffusion does not require energy in any situation.
Diffusion requires energy only to move material out through the cell membrane.
Answer:
Diffusion does not require energy in any situation.
Explanation:
Diffusion does not require energy because it is a form of passive transport.
which of the statements accurately describes how water moves through earth and its atmosphere
Answer:
A. Liquid water falls from outer space and is absorbed or d*unk by living things. It then evaporates into the atmosphere and forms clouds, which float into space.
Going long does carbon dioxide last
Answer:
carbondioxide last in about 300 to a 1000 years in the atmosphere
HELP, define genetic engineering and Describe how DNA is modified for use in genetic engineering.
Answer:
Genetic engineering is deliberate modification of genome to gain desired traits.
The main steps of genetic engineering:
Restriction enzymes are used to isolate the required gene leaving it with sticky ends. Sticky ends are a short section of unpaired bases A vector, which is usually a bacterial plasmid or a virus, is cut by the same restriction enzyme leaving it with corresponding sticky ends. The vector and the isolated gene are joined together by ligase enzyme. The vector inserts the gene into required cells. The genes are transferred to animal, plant or microorganism cells, during early development, which allows them to develop with the desired characteristics.
Punnett square for rr and rr parents
form and function are related. describe how the form of the tracheal wall is related to its four functions
Given what we know we can confirm that the tracheal wall is related to its function in that it allows it to conduct air in a sealed manner and protect the individual.
What is the function of the trachea?The primary function of the trachea is to conduct air into the lungs. For this, the trachea is long and narrow, to allow air to flow in a directed manner towards the lungs. The trachea is also "armored" to protect this air flow and is lined with mucus to sweep away any unwanted particles from the air.
Therefore, we can confirm that the trachea is armored and lined with mucus along its long, tube-like shape, which allows this structure to conduct air in a safe, clean, and direct manner directly towards the lungs.
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Sperm and eggs are found in different parts of plants. Explain why it is important for these
cells to unite, and describe some factors in an environment that help unite them.
Explanation:
When sperm and eggs in plants are united they fertilize the egg creating a plant able ready seed. Some factors in an environment that help them unite are; (animals) bees, butterflies, and other insects. wind bringing pollen around
When sperm and egg (found in different parts of plant) unite fertilization takes place which results in the formation of a zygote and later it forms an embryo.
Some factors in an environment that help unite them are air, water, insects, birds, bats etc.
What is sperm?"Sperm is defined as male reproductive cell. In case of plants, it is known as male gametophyte (pollen)."
What is egg?"Egg is defined as female reproductive cell. In case of plants, it is known as female gametophyte (ovum)."
What is fertilization?"Fertilization can be defined as the fusion of the male gametes (pollen) with the female gametes (ovum) to form a diploid zygote."
What is a zygote?"A zygote is a cell formed by the union of two gametes."
What is embryo?"A plant embryo is an undeveloped plant inside a seed."
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#SPJ2
High-efficiency particulate air (HEPA) filters are designed to remove which sized particles from the environment? 0.1 microns or smaller a) b) 0.3 microns or larger O c) 0.1 microns or larger d) 0.3 microns or smaller
Answer:
d) 0.3 microns or smaller
Brown hair is dominant and blonde hair is recessive.
What percent of the offspring will have blonde hair if the parents have the following alleles?
BB
Bb
A. 75
B. 25
C. 50
D. 0
E. 100
Answer:
If we assume B = Brown and b= blonde, Phenotypically the percent of offspring having blonde hair is D. 0
Explanation:
(i need some help here pls)
Before uniformitarianism, what theory was widely accepted?
1.) Uniformitarianism is the only theory
2.) The law of superposition
3.) Catastrophism
Answer:
3.)CATASTROPHISM
Explanation:
catastrophism suggested the features seen on the surface of earth such as mountains,were formed by large abrupt changes or catastrophes
HELP PLEASE!
In pea plants, petal coloration of has a complete dominance relationship where purplepetals are dominant over white petals. There are 276 plants, 273 have purple petals.Find: the frequency of the dominant and recessive alleles and the frequency ofindividuals with the dominant, heterozygous, and recessive genotype.
Answer: See below
Explanation:
In the selected pea plant population, there are total 276 plants out of them 273 have purple petals.
Remaining 276 - 273 = 3
q²= 3/276
q²= 0.010
q = 0.1
p + q = 1
p = 1 - 0.1
p = 0.9
Therefore:
Homo-zygous dominant = p² = 0.9×0.9 = 0.81
Hetero-zygous dominant = 2pq = 2×0.9×0.1 = 0.18
Homo-zygous recessive = q² = 0.1×0.1 = 0.010
horse is called a vertebrate reason scienc subjects
Answer:
Explanation:All animals with a backbone and skeleton are vertebrates. Horses have backbones and skeletons, therefore they are vertebrates. Animals without a backbone are called invertebrates. Hope this helps
Need Help Asap please. Question 1) Describe how the nervous system helps different parts of your body communicate with one another the moment you begin to pet a dog. ( Please make sure you answer this question completely and right). Will Mark Brainliest if answered correctly. Write a much as you can.
Answer:
When you pet a dog, your nerves send a signal to your brain of the soft, silky, warm fur of the dog. Your brain sends a signal back telling your arm to move up and down the dog. Your nerves feel the warmness and softness of his fur and send it to the brain. The brain relates this to other things and secretes hormones through glands which shows the pleasure.
Explanation:
Have a great day!
Pls mark me brainliest!
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_______ tells your cells what to do.
A. Genes
B. parent cells
C. white blood cells
D. Mitochondria
Genes :- they contain stored information which then orders cells through the process of translation
Homologous chromosomes may exchange segments; this is called crossing over. Crossing over increases genetic variability. When does crossing over occur?
Question 2 options:
Meiosis II
Mitosis
Both mitosis and meiosis--crossing over may occur at any time during the cell cycle.
Meiosis I
Question 3
In order for meiosis to create four, genetically different gametes, DNA replication must occur. Which of these best describes when DNA replication would occur?
Question 3 options:
prior to meiosis II
prior to meiosis I and meiosis II
prophase I in meiosis I
prior to meiosis I
Question 4 (1 point)
The embryo's development as seen here represents which processes in the development of any multicellular organism?
Question 4 options:
meiosis followed by mitosis.
mitosis and cell differentiation.
protein synthesis followed by meiosis.
meiosis and cell differentiation.
Question 5
Why do some organisms reproduce aseggsually?
Question 5 options:
To rapidly produce like offspring
To increase genetic diversity
To have a variety of offspring at the same time
To get rid of genetic problems while reproducing
A) Crossing over occurs in : Meiosis I ( D )
B) DNA replication would occur : Prior to meiosis I and meiosis II ( B )
C) The embryo's development represents ; meiosis and cell differentiation ( D )
D) Some organisms reproduce aseggsually ; To rapidly produce like offspring
What is Crossing over and DNA replication
Crossing over involves the swapping of genetic materials, and it occurs in prophase I of meiosis before meiosis II the crossing over of genetic materials are over. while DNA replication is the process whereby DNA make an exact copy of itself during the process of cell division and this process occurs prior to meiosis I and meiosis II
The development of an embryo in the missing diagram represents meiosis and cell differentiation.
Hence we can conclude that the answers to your questions are as listed above.
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what is cell and what are cell organalles
Answer:
a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body
so it is like a cell that works in the body but its a (organelles) in side the cell working in it like it is the cell in side the body
Which of the following illustrates the principle of induction in invertebrates?
A. In an embryo, the presence of a notochord beneath the ectoderm results in the formation of a neural tube.
B. A neuron synapses with another neuron via a neurotransmitter.
C. Eye muscles constrict in response to light.
D. Secretion of TSH stimulates the secretion of thyroxine.
E. The maternal parent induces spontaneous expression of recessive genes.
Answer:
A
Explanation:
A
How does the ectoderm that will make up the future eye know to develop into an eye? The cells are "told" to develop into an eye because the nearby retina releases chemical signals that direct the development of the cells. This process is called induction. Choice A depicts a similar situation. The notocord releases chemical signals that tell the overlying ectoderm that it is time for it to become the neural tube. None of the other choices depict the process of induction.
please help me what organism is the secondary consumer ?
Answer:
I believe it is the fox
Answer:
It would be most likey the worm dood.. most likely because he is a consumer that would gain his resources from the tree.
Explanation:
Find a picture or video regarding optical illusions and post a link. Describe what is happening in the eye or brain that creates that illusion!
Optical illusion occurs when our brain and eyes miscommunication with each other.
Why Optical illusions occur?Optical illusions happen when our brain and eyes speak to each other in simple language but the interpretation gets mixed-up. For example, our eyes told the brain that something is moving but that's not what the eyes meant to say to the brain which leads to the creation of illusion.
So we can conclude that Optical illusion occurs when our brain and eyes miscommunication with each other.
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How do creosote plants defend against predators?
by growing in hard-to-reach places
by growing sharp, stinging hairs over their bodies
by producing bad-tasting oil in their leaves
by producing deadly toxins in stems and leaves
Answer:
The answer should be By growing sharp, stinging hairs over their bodies.
Explanation:
Which one of the following is NOT a
characteristic of livings things?
A. must grow and develop
B. must be made of more than one cell
C. must be able to reproduce
D. must have a universal genetic code
Describe the nutrient cycle. How does soil contribute to this cycle?
Answer:
The nutrient cycle is a system where matter and energy are transferred between living organisms and non-living parts of the environment. This occurs as animals and plants consume nutrients found in the soil, and these nutrients are then released back into the environment via decease and spoilage
Some types of muscular dystrophy are X-linked recessive disorders. A mother who is a carrier for muscular dystrophy has children with a father who doesn’t have muscular dystrophy.
a. What percentage of their sons will have the disease, and what percentage of their sons will be carriers?
b. What percentage of their daughters will have the disease, and what percentage of their daughters will be carriers?
Show your work with a Punnett Square, using XD to represent the allele not associated with muscular dystrophy and Xd to represent the allele associated with muscular dystrophy. You can copy/paste the blank table below or create a table in the submission box to complete the Punnett square.
D gene is an X-chromosome-linked gene. a) 100% will have the disease, XdY // 0% will be carriers. b) 0% will have the disease // 100% will be carriers, XDXd.
What are the séx-linked genes?These are genes that can be found only in the X-chromosome. The inheritance pattern expressed by these genes varies from the one expressed by genes located in autosomal chromosomes.
In the exposed exampe,
- muscular dystrophy are X-linked recessive disorders
- woman ⇒ carrier for muscular dystrophy ⇒ heter0zyg0us ⇒ XDXd
- man ⇒ doesn’t have muscular dystrophy ⇒ X-chromosome with the dominant allele ⇒ XDY
- XD ⇒ chromosome rarrying the dominant allele
- Xd ⇒ chromosomes carrying the recessive allele
Cross: Man x Woman
Parentals) XDY x XDXd
Gametes) XD Y XD Xd
Punnett square) XD Xd
XD XDXd XDXd
Y XdY XdY
F1) 1/2 = 50% of the progeny will express the normal phenotype, XD-
1/2 = 50% of the progeny will have muscular dystrophy, Xd-
100% of the girls will be normal and carriers, XDXd
100% of the boys have muscular dystrophy, XdY
a. What percentage of their sons will have the disease, and what percentage of their sons will be carriers?
Considering only boys,
100% of them will have the disease, XdY0% will be carriers.b. What percentage of their daughters will have the disease, and what percentage of their daughters will be carriers?
Considering only girls,
0% of them will have the disease, 100% will be carriers, XDXdYou will elarn more about séx-linked genes at
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what is is the attraction of water molecule to each other
Which of the following best describes the relationship between the level of genetic
variation and adaptability?
Answer:
All adaptations are variations and all variations help organisms survive
Explanation:
hope this helps
Explain why the pattern of differences
that exists from earlier to later fossils in the
fossil record supports the idea that evolution
has taken place on Earth.
Answer:
Different layers of fossils found in sedimentary layers of the earth show that past species have died off and adapted in order to survive.
Explanation: