Answer:
400x
Explanation:
During the relative refractory period, _______. During the relative refractory period, _______. another action potential can be generated provided the stimulus is relatively smaller than the original stimulus. another action potential can be generated provided the stimulus is large enough. the flow of potassium is also depolarizing the neuron. a second action potential cannot be generated, no matter how strong the stimulus.
Answer:
During the relative refractory period, another action potential can be generated provided the stimulus is large enough.
Explanation:
The relative refractory period is the time after an action potential where the sodium channels are transitioning from inactivated channels to closed ones. In other words, voltage-gated Na+ channels have two gates, an external one and an internal one. During repolarization, the outer gate is blocking the entrance, and the internal one is open. So the channel is inactivated. When the inner gate is closed, the Na+ channel is closed.
During the relative refractory period, a second action potential can happen, but the stimulus has to be large enough to do it since the membrane is hyperpolarized, that is to say, the membrane potential is more negative than the resting action potential. The cell needs more Na+ ions to produce the second action potential.
Amino acids build
A. proteins
B. monomers
C. nucleic acids
Answer:
A. proteins
Explanation:
Amino acids builds up the proteins.
Which of the following is NOT a social science?
politics
geography
physics
economics
Answer:physics
Explanation:
Three potted plants were kept in a dark cupboard for two days before being used for an experiment. Each plant was then put under a bell jar under different conditions for six hours . Bell jar D contains a potted plant with a small cup of sodium hydroxide solution with light pointed towards it Bell jar E contains a potted plant with light pointed towards it Bell jar F contains a potted plant with aluminium foil on top of the bell jar with light pointed towards it a)explain why their was no starch in the leaves at the end of the two days in the cupboard b)what is the purpose of sodium hydroxide put under bell jar in D?
Answer:
a. There were starch in the leaves at the end of two days in the cupboard because there was no sunlight to provide the energy for photosynthesis in the dark cupboard. Also, any previously synthesized starch in the plant leaves were used by the plant for its own metabolic requirements during the period the plant was in the cupboard. Therefore, staying in the cupboard for two days destarched the leaves.
b. The purpose of sodium hydroxide put under bell jar in D is to remove any carbon dioxide that may be present under the bell jar. This is to demonstrate that even in the presence of sunlight, carbon dioxide is required for photosynthesis to occur in plants.
Explanation:
Photosythesis is the process by which green plants manufacture their food (carbohydrates which are stored as starch) in the presence of sunlight. The site of photosynthesis in plants is the leaves.
The experimental design is to study the conditions necessary for photosynthesis to occur. For photosynthesis to occur, there must be presence of sunlight, carbon dioxide and water. Carbon dioxide and water serve as the raw materials for photosynthesis while the energy required is provided by sunlight.
The answers to the observations from the experiment are given below :
a. There were starch in the leaves at the end of two days in the cupboard because there was no sunlight to provide the energy for photosynthesis in the dark cupboard. Also, any previously synthesized starch in the plant leaves were used by the plant for its own metabolic requirements during the period the plant was in the cupboard. Therefore, staying in the cupboard for two days destarched the leaves.
b. The purpose of sodium hydroxide put under bell jar in D is to remove any carbon dioxide that may be present under the bell jar. This is to demonstrate that even in the presence of sunlight, carbon dioxide is required for photosynthesis to occur in plants.
Can someone help me out these are my finals and i dont know
Meiosis in males produces four identical sperm cells.
A. True
B. False
Answer:
B. False
Explanation:
Meiosis in males, not produces four identical sperm cells.
Meiosis is a type of cell division which involves the reduction in chromosomal content to half. The four daughter cells formed in meiosis are not identical. Thus, the given statement is false.
What is Meiosis?Meiosis is a type of cell division in which the number of chromosomes reduces by half than that present in the parent cell and produces four haploid gamete cells. This process is required to produce both male and female gametes- egg and sperm cells for sexual reproduction.
During the telophase II- last phase of meiosis, cell division is incomplete without another round of cytokinesis. Once the cytokinesis is complete there are four daughter cells, each with half a set of chromosomes (haploid) which are different due to the crossing over between chromatids.
Learn more about Meiosis here:
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write any three write any three basis of evolution of living beings on the earth
Answer:
Hadean, archean, proterozoic
Seed tray can be used for sowing of cucumber seeds ______
True or false
Answer:
true
Explanation:
You can germinate cucumber seeds by direct seeding into a garden bed or in the soil in a seed tray.
Reproduction for dolphins and badgers and people is more complicated because
A. we have to apply for a license before we can reproduce
B. have to find a partner
C. go through the cellular process of MITOSIS to produce sex cells.
Answer:
B. have to find a partner
Explanation:
When two badgers get together and fall in love, a sperm cell from the father which contains a copy of half of his DNA, only half, combines with the egg cell of the mother, which contains half a copy of her DNA. The result is a brand new cell with all the information to divide and grow up into a brand new badger. The new child matures to be similar to our parents, but also unique, because she developed some traits from her mother’s DNA, and some from her father. Her new combination of traits can be passed on to her children, and again.
En este dominio existen gran variedad de procariotas, con diversidad morfológica y fisiológicas, en este están todas
las procariotas patógenas, su tamaño oscila entre 1 y 40 milimicras, es
a) Protista
b) Eubacteria
c) Archaea
d) Eukaria
Answer:
c) Archaea
Explanation:
Los dominios biológicos son los taxones de más alto nivel, por encima de los reinos y abarcando todos los taxones, caracterizándolos de la manera más generalizada posible, dentro de la clasificación científica. Hay tres tipos de dominios llamados Archaea, Bacteria y Eukarya. Entre ellos, el dominio conocido como Archaea es el que engloba a los organismos procarióticos, unicelulares y patógenos, es decir, capaces de provocar enfermedades en el ser humano.
the water in ponds and lakes is...
Answer:
freshwater
Explanation:
Answer:
Lakes and ponds are inland bodies of standing or slowly moving water.
hope it helps
It's 58 degrees outside and a meteorologist says a cold front is headed to you area. What should you wear to prepare? *
sandals
rain jacket
snow jacket
hat and gloves
Which of the following statements is MOST accurate: Group of answer choices Animals evolved during the Cambrian Explosion because the Earth was organized into a supercontinent called Pangea Animals evolved during the Cambrian Explosion because oxygen on Earth had become abundant Animals evolved during the Cambrian Explosion because the Earth had just recovered from an asteroid impact Animals evolved during the Cambrian Explosion because carbon dioxide on Earth had become abundant
Answer:
Animals evolved during the Cambrian Explosion because oxygen on Earth had become abundant.
Explanation:
Photosynthesis could be responsible for the rise in the amount of oxygen in the seas and atmosphere near the beginning of the Cambrian. This rise of oxygen concentration allowing the evolution of larger animals having complex respiratory and circulatory systems. So we can conclude that evolution in the physical and genetical characteristics of animals occur during the Cambrian Explosion.
Look at the karyotype. Which chromosome has an extra copy?
A. 2
B. 20
C. 18
Answer:
[tex]c.18[/tex]
hope it is helpful to you
Answer:
C 18
it is clear on rhe worksheet
but i hope it helps
Small changes can add up over MULTIPLE GENERATIONS to make
A. the same species
B. new species
Answer:
B: new species
Explanation:
These are mutations to the genetic code and over time they can create a new species.
Answer:
B. new species
Explanation:
Small changes can add up over multiple generations to make new species.
which landform can be created by wind
Answer:
Aeolian landforms
Explanation:
It is the landform created by wind and named for the Greek God of wind 'Aeolus'.
What's true about all three of the first babies?
A. They all have hair, but they have different genotypes
B. They all have the same genes but some have hair and some don't
Answer:
A. They all have hair, but they have different genotypes
Explanation:
A phenotype is your version of a trait. Blue eyes vs brown eyes and curly hair vs straight hair are examples of phenotypes. A genotype is your combination of genes that produce your phenotype.
Which of the following best describes the genetic material a person receives from his or her father?
Answer:
Paternal
Explanation:
Genetic material from the mother is maternal and genetic material from the father is paternal.
Which of the following can cause evolution to occur? (Select all that apply)
Mutation
If organisms choose a mate for a specific reason
People moving into or out of an area
If the population shrinks
Answer:
MutationIf organisms choose a mate for a specific reasonPeople moving into or out of an areaIf the population shrinksExplanation:
These factors are the "forces of evolution." There are four such forces: mutation, gene flow, genetic drift, and natural selection.
These are the factors that can cause evolution to occur:
MutationIf organisms choose a mate for a specific reasonPeople moving into or out of an areaIf the population shrinksWhich of the following is a FALSE statement about fungi?
A. Fungi may be multicellular or unicellular
B. Fungi are heterotrophs
C. Fungi have a cell wall made of chitin
D. Fungi are autotrophs
Answer:
D. Fungi are autotrophs
Explanation:
Fungi are autotrophs is a FALSE statement about fungi. Fungi are heterotrophs.
Explain the presence of starch in the parts of a plant that do NOT contain chlorophyll.
Answer:
In the leaf, excess glucose is rapidly converted to starch, so we test leaves for starch to show that photosynthesis has happened, rather than testing for glucose. We often indicate that light and chlorophyll are required for the process by adding them to the equation near the arrow.
On a cold day, the temperature of the air reaching alveoli is raised in the nasal passages because the
Which of these organs are parts of the brain?
а) cerebrum
b) cerebellum
c) brainstem
d) all of above
Answer:
all of above
Explanation:
What is the difference between gene mutations and chromosome mutations?
A. Gene mutations are preventable and chromosome mutations are not
B. Gene mutations can happen easily and chromosome mutations are more difficult
C. Gene mutations only affect one gene while chromosome mutations affect many genes
Answer:
C. Gene mutations only affect one gene while chromosome mutations affect many genes.
Explanation:
The difference is that the gene mutations only affect one gene while chromosome mutations affect many genes.
What does DNA prove about organism ancestry?
A. Plants and animals are not related to one another
B. That all organisms are related to one another
C. DNA and RNA are completely different forms of genetic coding
D. Extraterrestrial life will have DNA as well
Answer:
B. That all organisms are related to one another
Answer:
B. That all organisms are related to one another
Explanation:
Fossils, anatomy, embryos, and DNA sequences provide corroborative lines of evidence about common ancestry, with more closely related organisms having more characteristics in common. DNA underlies the similarities and differences in fossils, anatomy, and embryos.
Adrenergic receptors Select one: a. can be activated by the release of epinephrine. b. have two structural forms - muscarinic and nicotinic. c. when activated stimulate skeletal muscles to contract. d. can be found in both the sympathetic and parasympathetic divisions. e. are activated by the release of acetylcholine.
Answer:
The correct answer is a. can be activated by the release of epinephrine.
Explanation:
Epinephrine is a hormone and neurotransmitter naturally secreted by the body through the adrenal glands, synthesized and stored in the adrenal medulla and released into the systemic circulation. Epinephrine is a non-selective adrenergic agonist, stimulating alpha1-, alpha2, beta1, and beta2-adrenergic receptors. The systemic actions of catecholamines are mediated by the binding of these compounds to plasma membrane receptors, of the GPCR type widely distributed throughout the body and known as adrenergic receptors, which are activated by the catecholamines adrenaline (epinephrine) and noradrenaline . These receptors cause different effects depending on the G protein subtypes to which they are associated and the signal transduction mechanism linked to the specific G protein.
Why do identical twins separated at birth show DIFFERENCES as seen in the pictures?
A. Their DNA changed because of the different environments they lived in.
B. Different genes were turned on or off because of he different environments they lived in.
Answer:
B. Different genes were turned on or off because of the different environments they lived in.
Explanation:
Your DNA does not change but it can turn on some parts and off others depending on your enviroment.
Answer:
B. Different genes were turned on or off because of he different environments they lived in.
Explanation:
The identical twins separated at birth show different genes were turned on or off because of he different environments they lived in.
A scientist studied a population of birds for 10 years. During that time, the population was never fewer than 30 birds and never more than 50. Her data showed that over half of the birds born did not survive to reproduce, because of competition for food and predation. She noticed that In a single generation, about 90% of the birds that were born lived to reproduce, and the population increased to 90. Which inference(s) about this population might be true
Answer:
A particular population limiting factor or factors must have been removed
Explanation:
The population of the birds must have been kept between 30 and 50 individuals by population limiting factors such as the presence of predators within the community or competition for resources such as food or spaces.
For the population to shoot up to 90 all of a sudden, it may be that one or more of the population limiting factors has been removed from the population. It could be that a major predator has been removed from the community or the competition for food/space is now significantly reduced due to more food/space in the community.
Which is the site of the most ATP production during cellular respiration?
nucleus
mitochondrion
cytoplasm
chloroplast
Answer:
mitochondrion
Explanation:
the mitochondrion
State two similarities and two differences between an
amoeba and a plant cell:
Answer:
S: Both are eukaryotic (1) and contain a cytoplasm + vacuole (2).
D: Amoebas lack a cell wall (1) and are not photosynthetic organisms (2).
Explanation:
