Scientists use historical major geological and biological events to characterise the geological time scale.
Paleontologists, archaeologists, and geologists use the fossil record to put significant occurrences and species in the right geological epoch. The geologic time scale is fundamentally based on fossils. Because these time periods are frequently identified based on the presence of animal life, the names of the majority of the aeons and eras end in zoic. Fossil remains of relatively simple organisms, like bacteria, algae, and worm-like animals, have been found in rocks formed during the Proterozoic Eon.
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What is the common function of leaves?
store water
transport energy
transport water
make energy
The common function of leaves are: water storage, energy transportation water transportation and energy synthesis.
Describe the function of leaves.The main function of leaves is to produce food for plants through photosynthesis. Chlorophyll, the substance that gives plants their unique green color, absorbs light energy. The internal structure of the leaf is protected by the stem epidermis and the continuous leaf epidermis. The central sheet or mesophyll is composed of soft-walled, unspecialized cells of a type known as the parenchyma. Up to one-fifth of the mesophyll consists of chlorophyll-containing chloroplasts that absorb sunlight and, in combination with specific enzymes, use radiant energy to break down water into its elements hydrogen and oxygen. . Oxygen released by green leaves replaces oxygen removed from the atmosphere by respiration and combustion of plants and animals. Hydrogen obtained from water combines with carbon dioxide in the enzymatic process of photosynthesis to form sugars that form the basis of plant and animal life. Oxygen is released into the atmosphere through stomata (stomata on the leaf surface).
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Which efferent pathway has a single nerve fiber extending from the cns to effector?.
Somatic is a efferent pathway has a single nerve fiber extending from the CNS to effector.
The nerves that travel to and from the spinal cord and transmit signals to and from the muscles and senses are collectively referred to as the somatic nervous system (SNS). Efferent routes, which control motor functions involved in movement of the body and limbs, typically transmit information from the spinal cord to the muscles.
Axonal projections that leave a region are referred to as efferent nerve fibers, as opposed to axonal projections that enter the region. In the context of the central nervous system (CNS) and peripheral nervous system (PNS), these terms have a slightly different meaning.
Hence, somatic is a efferent pathway of a single nerve fiber.
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Somatic is an efferent pathway with a single nerve fiber extending from the CNS to the effector.
The nerves that enter and leave the spinal cord and carry signals to and from muscles and sensations are collectively called the somatic nervous system (SNS). Efferent pathways, which control the motor functions involved in body and limb movements, normally transmit information from the spinal cord to the muscles. Axonal projections exiting a region are called efferent nerve fibers, as opposed to axonal projections entering a region. It is associated with the central nervous system (CNS). and peripheral nervous system “PNS.” These terms have slightly different meanings.
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A helper T-lymphocyte becomes activated by a(n):
Plasma cell
Antigen presenting cell
B-lymphocyte
Memory cell
A helper T-lymphocyte becomes activated by Antigen presenting cell.
What is Antigen presenting cell?Pay attention to how it sounds. Zen-ting sel (AN-tih-jen-preh) a particular class of immune cell that stimulates immunological responses by exposing immune system cells to antigens on its surface. A particular class of phagocyte is an antigen-presenting cell.The three main antigen-presenting cells are B lymphocytes, macrophages, and dendritic cells. T lymphocytes are given extracellular antigen to be cleared by these cells.Dendritic cells (DCs) and B cells are examples of traditional antigen-presenting cells (APCs) (10). APCs must first recognize and bind their target in order to launch an immune response. APCs express antigen-specific surface receptors, such as pattern recognition receptors, to do this (PRRs).To learn more about Antigen presenting cell refer to:
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what is the relationship between chromosomal instability and cell proliferation characteristic of tumorigenesis?
The likelihood of obtaining cells with a higher rate of proliferation increases with increasing chromosomal instability.
What traits do cancers possess?Cancerous and postoperative pain, the inhibition of antitumor immunity, tumor angiogenesis, tumor proliferation, development, and metastasis, as well as mental depression, are all clinical biological symptoms of malignancies.
What features distinguish an tumorous cell growth?Uncontrolled cell division as well as the inability of their wear are features of tumor cell proliferation.Additionally, tumor cells are more likely to survive.Resistance to apoptosis (the body's natural death process) is acquired by tumor cells.
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you find an animal with a bilateral larval form but what appears to be a radial adult form. which taxa would you presume it to belong to?
The animal would be presumed to belong to Cnidaria if they have a bilateral larval form and radial adult form.
In the Cnidaria larvae, bilateral symmetry is a characteristic feature. In the field of biology, bilateral symmetry can be described as a type of symmetry in which when an organism is cut into half, both the right and the left side appear to be exactly similar.
However, after growth from the larval stage, the Cnidaria adults develop to have radial symmetry. In the field of biology, radial symmetry can be described as a type of symmetry in which the body has a central axis where all the lines or planes of the body of the organism can unite. A radial symmetry has a central axis.
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only the fibrous layer can be observed in its entirety from the superficial surface of the cow eye.
The only part of the cow eye's surface that can be seen in its entirety is the fibrous layer.
What role does the fibrous layer play in the body?Fibroblasts, which form the collagenous fibers that give the skin structure and fortify bones, are present in the outer fibrous layer. Blood arteries in this layer also provide the cartilage its nutrients and oxygen.
What do you call the fibrous layer?The periosteum is made up of an inner and an exterior "cambium layer." Fibroblasts are found in the fibrous layer, whereas progenitor cells found in the cambium layer give rise to osteoblasts, which widen the bone.
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The offspring of two true-breeding parents that differ in a single character are called single-character hybrids, or.
The offspring of two true breeding parents that vary in only one character are known as single character hybrids or monohybrids.
A monohybrid cross occurs when two true-breeding parents, that are distinct exclusively in the trait under investigation, mate and the resulting offspring are referred to as monohybrids or single character hybrids.
Mendel hypothesized after conducting seven distinct monohybrid crosses that each parent in such a cross passed on one of two paired unit factors to each offspring. Additionally, each and every feasible combination of these unit factors was equally possible. Mendel found that in the offspring in the F₂ generation exhibited a phenotypic ratio of 3:1.
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a population is . question 38 options: a group of individuals of several interacting species that live in one area a group of individuals of a single species that live and interact in one area the sum of all individuals of a species in all locations a group of individuals of several interacting species that interact in multiple ecosystems a group of cells that have similar function
A population is a group of individuals from the same species who live and interact in the same area.
A population's health and behaviour are determined by how individuals interact with one another and with their surroundings. The community is made up of many such populations that interact with one another.
The ecosystem is made up of the biotic community and the abiotic environment. And a biome develops as a result of similar climatic conditions in a region; these regions are typically large, encompassing many continents. It can be thought of as a collection of various ecosystems. An ecosystem is a geographical area in which plants, animals, and other organisms, as well as weather and landscapes, coexist to form a life bubble.
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what triggers a b-cell to proliferate and differentiate, and what cell types/functions this creates
Creation of fully developed immune-competent B cells maturation. Maturity-dependent B-cell activation and differentiation into plasma cells and memory B cells.
B-cell production starts in the embryo and continues throughout life.Major locations of B cell maturation before birth include the yolk sac, foetal liver, and foetal bone marrow.Following birth, hematopoietic stem cells in the bone marrow produce mature B-cells (HSC).The HSC first divide to create lymphoid progenitor cells, and these cells subsequently differentiate and maturation into progenitor B-cells (pro B), which express a transmembrane tyrosine phosphatase known as CD45R and a signalling molecule known as Ig/Ig that is later identified linked with the membrane-bound antibody.Pro-B cells furthermore exhibit CD19 (part of co-receptor),CD43 (leukosialin), CD24 (heat stable), and C-kit are present on the surface of Pro-B-cell.To know more about b-cells check the below link:
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What is/are the function(s) of centrioles in the cell?
Choose all that apply:
Aid in anchoring organelles to their spots
Help cells maintain their shape
Creation of microtubules that aid in cell division
Aid in the mechanical movement of basal bodies
Assist in the movement of motor proteins
The main function of the centrioles in the cell is the creation of microtubules that aid in cell division (Option 3).
What is the role of the centrioles in animal cells?The centrioles are exclusive organelles observed in animal cells whose main role is to migrate to opposite ends in a cell by organizing microtubule filaments of the cytoskeleton.
Therefore, with this data, we can see that the main role of centrioles in animal cells is to organize the formation and movement of the microtubule filaments of the cytoskeleton during the process of cell division.
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NEED HELP ASAP!!!!!!!
Cacti can survive with very little water.
Which statement describes why cacti have this ability?
(choose only one answer)
A. Cacti have a homeostatic system to control water loss.
B. Cacti do not have pores through which they can release excess water.
C. Cacti require a large amount of water.
D. Water is poisonous to cacti.
Statement cacti have a homeostatic system to control water loss describes why cacti have this ability.
What are the features of homeostatic system?Homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables.
Moreover, body temperature control in humans is one of the most familiar examples of homeostasis. Normal body temperature hovers around 37 °C (98.6 °F), but a number of factors can affect this value.
The homeostatic pathway controls energy balance by increasing the motivation to eat following depletion of energy stores.
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passive transport is the movement of molecules across the cell membrane without requiring an input of cellular energy. identify which of these options are examples of passive transport.
A. True
B. False
what is the primary difference between the innate and adaptive immune responses?
The body's initial line of defence against infections is innate immunity. It is broad and non-specific, which means it does not distinguish between pathogen kinds. Adaptive immunity is a form of immunity that develops as a result of disease exposure or vaccination.
What cells participate in innate and adaptive immunity?There are several cell types that each play a unique function in immunity. These comprise macrophages, neutrophils, eosinophils, basophils, mast cells, and dendritic cells generated from myeloid progenitors in the innate immune response. Natural killer cells are also part of the innate immune system, but unlike the other cells, they are produced from lymphoid stem cells.
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If a scientist wanted to determine if a forest environment had been polluted, which group of organisms typically would be the best indicator for the presence of pollutants?.
Amphibians would have been the best indicator of pollutants if a scientists wanted to determine if a forest environment had been polluted.
Amphibians are the vertebrates animals belonging to the phylum Chordata. These are ectothermic and four-limbed animals. These organisms need water or moist environment to complete their life cycle. They are good indicators of pollutants because they are highly sensitive to chemical changes in the environment.
Pollutants are the agents that cause disturbing effects in the environment called pollution. The pollution causes harmful effects upon the living organisms. The examples of pollutants are: Ozone, particulate matter, sulfur dioxide, etc.
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prophase i accounts for over 80% of the time that the primary spermatocyte spends in meiosis i. why do you think so much time is needed in just this one stage
The reason why prophase 1 takes so long is because the cell must go through homologous recombination and cell checks to ensure that crossovers are finished before entering metaphase 1.
How many spermatozoa can be produced from a single primary spermatocyte?Each primary spermatocyte that goes through meiosis develops into four sperm. During pregnancy, stem cells are implanted, and they are still there at delivery and the start of adolescence, but they remain dormant.
What do people refer to when they produce male sperm cells?Male germ cells are created in the seminiferous tubules of the testes from a self-renewing stem cell pool throughout life, from adolescence to old age. Spermatogenesis refers to the entire process of developing germ cells.
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How are the male and female reproductive systems similar in function, organs and organ structure, and
hormones?
Reproduction is the process through which creatures produce offspring, to put it simply. All living things share this miraculous quality, which distinguishes them from inanimate objects. However, even while a species' reproductive system.
Two different types of gametes, or sex cells, are used in human reproduction. The female reproductive system must bring together sperm, the male gamete, a secondary oocyte, the female gamete, together with the first polar body and corona radiata, in order to produce a new individual.
Similarities:
Male and female reproductive systems have some fundamental similarities and some specialized distinctions. They are similar because they are homologous, which means that the majority of the reproductive organs in both sexes grow from the same embryonic tissue. Gonads, which generate sperm, eggs, or ovums, and sex organs, are present in both systems. Additionally, the reproductive organs in both systems mature and develop sexual function during puberty as a result of gonads secreting sex hormones.
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what is the difference between the closed conformation and open conformation of chromatin packing? biology
The shape of chromatin, which can be either open (euchromatin) or compact (heterochromatin), is dynamically regulated during the phases of the cell cycle is the two types of conformations.
The main distinction between conformation and configuration is that whereas the configurations of the same molecule do not easily interconvert, their conformations do.With a predefined location in the nucleus and a certain form, such as metacentric, submetacentric, acrocentric, or telocentric, chromosomes are primarily heterochromatic in this stage.All DNA-mediated processes, including gene regulation, can be significantly impacted by the degree of nucleosomal packaging. While heterochromatin (tight or closed chromatin) is more compact and resistant to factors that need to access the DNA template, euchromatin (loose or open chromatin) structure is permissible for transcription.
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as indicated in the kegg pathways for fatty acid degradation and biosynthesis, which pathway does not use acetly-coa as a substrate
As indicated in the kegg pathways for fatty acid degradation and biosynthesis, D. glycolysis pathway does not use acetly-coa as a substrate.
Glycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy launched in this manner is used to form the high-energy molecules adenosine triphosphate and decreased nicotinamide adenine dinucleotide. Glycolysis is a series of ten reactions catalyzed by enzymes.
Glycolysis is a series of reactions that extract power from glucose by means of splitting it into 3-carbon molecules referred to as pyruvates.
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Disclaimer:- your question is incomplete, please see below for the comlete question.
as indicated in the kegg pathways for fatty acid degradation and biosynthesis, which pathway does not use acetly-coa as a substrate
A. citric acid cycle
B. butanoate metabolism
C. fatty acid biosynthesis
D. glycolysis
A student builds a model of the heart and brain, shown in the diagram. Two trucks, 1 and 2, travel between the organs. The student will label the trucks with what they are carrying. Which set of labels BEST completes the model? Responses A Truck 1 carries red blood cells and Truck 2 carries white blood cells.Truck 1 carries red blood cells and Truck 2 carries white blood cells. B Truck 1 carries carbon dioxide and Truck 2 carries oxygen.Truck 1 carries carbon dioxide and Truck 2 carries oxygen. C Truck 1 carries white blood cells and Truck 2 carries red blood cells.Truck 1 carries white blood cells and Truck 2 carries red blood cells. D Truck 1 carries oxygen and Truck 2 carries carbon dioxide.
According to statement, Truck 2 transports oxygen, while Truck 1 transports carbon dioxide.
What are the uses of oxygen?Respiration, the energy-generating process that fuels all metabolic rates in the majority of living things, is significantly oxygen dependent. All living creatures, including people, are reliant on air to survive.
What are 5 common uses of oxygen?Throughout order of importance, the following are the main uses of oxygen: 1) the melting, refining, and production of steel; 2) the production of chemicals through governed combustion; 3) booster propulsion; 4) the provision of medical as well as biological life support; and 5) the extraction, production, and manufacturing of stone as well as glass products.
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Why don't cells use endocytosis to transport all substances across the cell membrane.
In 100 to 150 words, compare and contrast the U.S Revolution and the South American Revolution.
Answer:
a
Explanation:
what blood disorder is characterized by a lack of oxygen reaching the body's cells? a.) anemia b.) septicemia c.) toxemia d.) leukemia
The correct option is a.) anemia i.e. blood disorder is characterized by a lack of oxygen reaching the body's cells.
Anemia: Your body feels chilly, exhausted, and weak because your blood does not carry enough oxygen. Your body loses more blood cells than it can make, leading to blood loss. Damage to your bone marrow, which is where red blood cells are made, results from a bone marrow condition (leukemia, lymphoma).Blood is a bodily fluid found in the circulatory systems of humans and other animals that carries metabolic waste products away from the cells as well as vital nutrients and oxygen to the cells. Peripheral blood and the blood cells it contains, peripheral blood cells, are terms used to describe the blood in the circulatory system.To know more about anemia
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The synthesis of cholesterol is a process that involves over 30 different steps. Which step is the rate-determining step of cholesterol synthesis?.
The rate-determining step of cholesterol synthesis is the conversion of HMG-CoA to mevalonate by HMG-CoA reductase.
Cholesterol is the wax-like substance which is produced by the liver in animal body. It is essential for plasma membrane fluidity. Blood cholesterol is also good for health at certain levels. However, excess of blood cholesterol can cause serious diseases as well.
Mevalonate is a key compound for the synthesis of cholesterol and also other sterols. The pathway for this synthesis is called the mevalonate pathway. It occurs in the cytosol of the animals cells. HMG-CoA reductase is a key enzyme for the synthesis of mevalonate.
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the binding and release of sodium or potassium ions are due to conformational changes in the protein.
After releasing ions into the extracellular fluid, the binding and release of sodium or potassium ions is caused by conformational changes in the protein.
Which type is in charge of the conformational modification that takes place in the sodium-potassium exchange pump?The pump adapts to phosphorylation by changing its shape and turning around to open toward the extracellular area. The three sodium ions are released outside the cell because the pump in this conformation no longer prefers to bind to sodium ions (has low affinity for them).
What are the two causes of the motion of the sodium and potassium ions?The differential in ion concentrations between the intracellular and extracellular regions, as well as the membrane potential, dictate the net flow of ions across an open ionic channel.
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Based on the karyotype below, what disorder does this individual have?
A. Turner’s syndrome; 45 chromosomes; X0
B. Kleinfelter syndrome; 47 chromosomes; XXY
C. Down syndrome; 47 chromosomes; trisomy 21
D. Patau syndrome; 47 chromosomes; trisomy 13
The type of disorder illustrated in the karyotype above is Klinefelter syndrome; 47 chromosomes, XXY (option B).
What is Klinefelter syndrome?Klinefelter syndrome is a genetic condition in which a person (male) is born with two X chromosomes and one Y chromosome i.e. the male has an extra X chromosome.
The chromosomal disorder observed in individuals with Klinefelter syndrome is known as aneuploidy, which is the state of possessing a chromosome number that is not an exact multiple of the haploid number of the organism in question.
According to the karyotype shown in the above image, there is an extra chromosome added to the normal chromosome pair of 23, making the total number of chromosomes add up to 47 instead of 46.
Therefore, option B is the correct representation of the karyotype.
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I need help pls high point. Really need help
Processes:
The Hawaiian Islands were formed by volcanic activity.
Each island or submerged seamount in the chain is successively older toward the northwest. Near Hawaii, the age progression from island to island can be used to calculate the motion of the Pacific Oceanic plate toward the northwest
How they are formed:
As a crustal tectonic plates move over hot spots mantle material up wells and erupts on the surface of the plate to form a volcano, seamount or volcanic island.
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Pls help me with this question asap !!!
Give an example of a disease caused by cells that have “gone wrong” or become dysfunctional. Explain how this disease is caused.
Answer:
Disturbances in cell death pathways at the molecular level can be linked to the pathogenesis not only of cancer, but also other diseases of enormous social importance, such as HIV, atherosclerosis, ischemia, reperfusion injury, infection, inflammation, autoimmune, and neurological disorders
Explanation:
you can just say the answer
Photosynthetic rate incrases steadiky as light level increse
What is photosynthesis?Photosynthesis is defined as a process in which solar energy is captured and organic molecules are produced. This process is fundamental for the survival of life on the planet and is the main way in which energy enters the biosphere.
Where does photosynthesis take place?Photosynthesis takes place in chloroplasts. Chlorophyll and carotenoids are arranged in the thylakoids of chloroplasts in units called photosystems. Two steps can be observed in photosynthesis: light reactions and carbon fixation reactions. At the end of photosynthesis, carbohydrates are produced.
How is ATP produced in the cell?The breakdown of glucose occurs to generate ATP. In organisms without mitochondria, such as bacteria, respiration takes place in a structure called a mesosome. This process uses glucose and oxygen and produces ATP, carbon dioxide and water.
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Name 2 tructure ,viible with a light microcope, which ditinguih plant cell from animal cell
The cell wall and the vacuoles are the two features that can be seen under a "light microscope."
The cell membrane is present underneath the cellulose-based cell wall in plant cells, but only the cell membrane is present in animal cells. The plant cell is larger than the animal cell because it has more vacuoles than the animal cell does, which makes them different in size. Additionally, the vacuoles occupy a "large volume" of the cell.
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You decide you don’t like worm o you go into your backyard and dig up all of the earthworm. Explain how removing the earthworm could affect the ecoytem in your yard
Worms are helpful when they die the techniccally turn into fertiliser in a way