Which group evolved first?
rays
skates
sharks
chimaeras

Answer:

1. 1s² Grupo: 18  Periodo: 1

2. 1s²2s²2p⁶3s¹ Grupo: 1 Periodo: 3  

3. 1s²2s²2p⁶3s²3p⁶4s² Grupo: 2 Periodo: 4  

4. 1s²2s²2p⁶3s²3p⁶4s²3d¹ (electrones de valencia) Grupo: 3 Periodo: 4

5. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p³ (electrones de valencia) Grupo: 15 Periodo: 4

Explanation:

La configuración electrónica de los elementos es la disposición de todos los electrones de un elemento en niveles y subniveles de energía (orbitales).

Hay 7 niveles de energía, numerados del 1 al 7, y en los que los electrones se distribuyen, lógicamente, en orden según su nivel de energía. Los electrones con menos energía girarán en el nivel 1. Cada nivel se divide en subniveles. Estos subniveles en los que se divide cada nivel pueden ser hasta 4. Estos 4 subniveles se denominan: s, p, d, f. En el subnivel s solo puede haber un máximo de 2 electrones, en p puede haber un máximo de 6 electrones, en el subnivel d 10 electrones y finalmente en el subnivel f puede haber un máximo de 14 electrones.

Por otro lado, los electrones de valencia son los electrones que se encuentran en la última capa electrónica (denominada orbitales de valencia) y tienen muchas posibilidades de participar en una reacción química.

En la tabla periódica, en cada período aparecen los elementos cuyo último nivel de su configuración electrónica coincide con el número del período, mientras que en cada grupo aparecen los elementos que presentan el mismo número de electrones en el último nivel ocupado o capa de valencia. Entonces:

1. 1s² Grupo: 18  Periodo: 1

2. 1s²2s²2p⁶3s¹ Grupo: 1 Periodo: 3  

3. 1s²2s²2p⁶3s²3p⁶4s² Grupo: 2 Periodo: 4  

4. 1s²2s²2p⁶3s²3p⁶4s²3d¹ (electrones de valencia) Grupo: 3 Periodo: 4

5. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p³ (electrones de valencia) Grupo: 15 Periodo: 4

Answer:

the right answer is tree frog

Explanation:

Answer:

is that a question?

Explanation:

Answer:

i’m not a 100% sure but i think it’s A

Answer:

increases the ability of wastes to diffuse out of the organism

Explanation:

A small size of an organism is advantageous for marine organisms because it increases the ability of wastes to diffuse out of the body of organism. Small size of an organism produces less amount of waste material and these organism does not need a very special and complex excretory system so simple diffusion of waste material occurs from the body in order to clean the body.

Answer:

bar graph can be easily converted to pie chart

Answer:

the founder effect, a form of genetic drift

Explanation:

Genetic drift is the change in the frequency of alleles in a population due to random sampling of organisms.

The founder effect is the reduced genetic diversity created when a population is descended from a small number of colonizing ancestors.

Answer:

b transformation

Explanation:

In transformation, a bacterium takes up a piece of DNA floating in its environment. In transduction, DNA is accidentally moved from one bacterium to another by a virus. In conjugation, DNA is transferred between bacteria through a tube between cells.

Answer:

Sebum

Explanation:

The sebaceous gland produces sebum, an oily, waxy substance. Sebum lubricates the skin and hair of mammals.

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Answer:

True, nitrogen fixation converts atmospheric nitrogen into nitrogen that can be used by plants.

Explanation:

Think about water. There's plenty of water on Earth, but very few is actually drinkable, at least for humans. So we have to fix it by filtering out dangerous bacteria in the water and other dangerous stuff before being able to actually drink it. Same with atmospheric nitrogen. It must be "fixed" before plants can actually use them.

A gas is given off when two substances are mixed.

physical change: A copper rod is hammered into a thin sheet.

A solid forms when two clear liquids are mixed.

A matchstick changes color when it burns.

explanation

a physicals change vs chemical

physical change is like cutting, changing shape etc, it the molecules that make it and the chemicals of it stay same

chemical change when it chemically changed such as cooking meat

Answer:

Water molecules tend to stick together due to the structure and charge of the atoms present in the water. Hydrogen atoms are positively charged while oxygen atoms are negatively charged. ... All water molecules are exerting cohesive forces on all the molecules around them including those on the surface of a body of water

Answer:

Orchids

step by step explanation:

Orchid is a flowering plant. So, the correct option is C.

Angiosperms, or flowering plants, are a category of plants that generate flowers as a component of their reproductive processes. With over 300,000 recognised species, they are the biggest and most varied group of plants. Flowering plants range across sizes from tiny herbs to massive trees and can be found in nearly every region on the planet, from deserts to rainforests, oceans to mountaintops.

Flowering plants are economically and ecologically significant because they provide humans with food, fiber, medicine, and ornamental value while also functioning as crucial components of many ecosystems.

Orchids are an extensive and widespread blooming plant family, with over 25,000 species found worldwide. They are well-known for their spectacular, fragrant flowers that come in a broad range of forms, sizes, and colors.

Therefore, the correct option is C.

Learn more about Flowering plants, here:

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Answer:

The correct answer is - species at risk for extinction.

Explanation:

Extinction is a threat to species of any living organism. The death or removal of last individual of a species is the condition of extinction.

It is commonly referred to the species as mostly species extinct from earth. Any size or type of species of living organism can be extinct.

The option that is not one of the steps of the water cycle includes options C(Respiration of water into the atmosphere)

and D(Transpiration of water into the atmosphere).

Water cycle can be defined as the constant flow or movement of water through earth, atmosphere and the oceans either in liquid states or vapour.

The four main steps of water cycle includes:

In nature, water circulates mainly within the abiotic (non-living) environment; only a small proportion recycled through living organisms.

Therefore respiration and transpiration which occurs through living organisms doesn't form the major steps of water cycle, hence the correct option is C (Respiration of water into the atmosphere) and D (Transpiration of water into the atmosphere).

Learn more about water cycle here:

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The correct answer is B. She was measuring a rate of change.

Explanation

A linear graph is a type of graph that contains a series of data represented by points joined by linear segments, which allow you to quickly check the change in the trend of the data. Therefore, inline graphs quantitative variables are usually used to see their behavior over time. According to the above, Anjuli had to use a linear graph to express the information in the graph more clearly, because the data that he was using in his graph were quantitative variables. Also, she wanted to express the respiration rate of the yeast per minute. According to the above, the correct answer is B. Ella She was measuring a rate of change.

Answer:

Cofilin binds to older actin filaments

Explanation:

Microfilaments (also called actin filaments) are a class of protein filament common to all eukaryotic cells, which consist of two strands of subunits of the protein actin. Microfilaments form part of the cell's cytoskeleton and interact with the protein myosin in order to allow the movement of the cell. Within the cell, actin may show two different forms: monomeric G-actin and polymeric F-actin filaments. Microfilaments provide shape to the cell because these filaments can depolymerize (disassemble) and polymerize (assembly) quickly, thereby allowing the cell to change its shape. During the polymerization process, the ATP that is bound to G-actin is hydrolyzed to ADP, which is bound to F-actin. ATP-actin subunits are present at the barbed ends of the filaments, and cleavage of the ATP molecules produces highly stable filaments bound to ADP. In consequence, it is expected that cofilin binds preferentially to highly stable (older) filaments ADP-actin filaments instead of ATP-actin filaments.

Answer:

nalaqdua

Explanation:

sbospka ai9wlhzux5 s8fvekg

Answer:

These organisms can live in anaerobic conditions.

Explanation:

These organisms can live in anaerobic conditions due to death occur in the presence of oxygenated environment or aerobic environment because these organisms are allergic oxygen and open environment. They have to be cultured and colonized in anaerobic condition means without the presence of oxygen so we can say that these organisms lives anaerobically.

Answer:Hyphae are the feathery filaments that make up multicellular fungi. They release enzymes and absorb nutrients from a food source. Hyphae have a firm cell wall made of chitin.

Explanation:

Answer:

They are made of the feathery filaments that make up multicellular fungi

Answer: 1. only A

Explanation: bio means living

Answer:

(a) Dry weight of living organism

hope this help you

Answer:

auxins and cytokinins

Explanation:

the two hormones induce growth for plants

Answer:

Enzymes and substrates bind to each other associating through various interactions, including hydrogen bonds, hydrophobic interactions, and covalent bonds.

Answer: The correct option is (the region of an enzyme that attaches to a substrate).

Explanation:

The anabolic and catabolic processes in a cell are directed and regulated by enzymes. An enzyme has the ability to speed up a metabolic reaction by lowering the amount of energy needed to start the reaction. Without enzymes, these processes would be extremely slow. They also arrange the reacting molecules in a manner that will cause the chemical change to take place rapidly. It does so through the following steps:

--> molecules of substrate combine with the enzyme at its active site.

--> the substrate molecules combine with enzyme molecules for a short time, forming an enzyme-substrate complex.

--> New substance ( product) is formed which leaves the active site of the enzyme thereby making it free for another reaction to take place.

In conclusion, the ACTIVE SITE of an enzyme is the region of an enzyme that attaches to a substrate allowing chemical reaction to take place.

Answer:

D) bilayer membranes

Explanation:

Two lipidic bilayers compose the cell membrane. There are also proteins and glucans incrusted in between. Lipids are amphipathic molecules with hydrophilic heads -negatively charged phosphate group- and hydrophobic tails. Lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane. Membranes are fluid, which means that the composing molecules can move through them.

Lipids can easily change places with other neighboring lipids by lateral diffusion in the same layer. This is passive diffusion, which means that it does not need energy to happen.

Lipids can also diffuse transversally to the other layer but not as easily as lateral diffusion. Jumps between monolayers are infrequent as the lipidic polar heads meet the fatty acid barrier.

There are also other lipidic movements as rotational diffusion that imply the rotation of the molecule.  

Complete question:

Sea urchins belong to the echinoderm phyla. Adult sea urchins have spines that extend outward from their exoskeleton, but as larvae, the sea urchins have only an exoskeleton made from spicules. The spines offer protection against predators. Sea urchins typically spawn near the surface. Males release sperm into floating plankton, then female urchins release between eight and 20 million eggs in the same area. The jelly-like coating on the eggs attracts the sperm, and when the two meet, they create an embryo that starts dividing into new cells within minutes.

Based on the information the population size of sea urchins is low in relation to the carrying capacity of the area. As a result, the sea urchins are

A) r-strategists that allocate much energy toward parental care.

B) r-strategists that allocate energy to producing many young.

C) density-independent because there is plenty of energy.

D) irruptive, because their numbers crash quickly.

Answer:

B) r-strategists that allocate energy to producing many young.

Explanation:

According to the given information, this species expresses survival curve type III, characteristic of r-strategists. Males and females release many gametes into the sea. If these gametes get to meet, they produce the embryo that starts developing. But there are high chances for these new organisms to die. Significant mortality during the early stages of life is expected for the species. The few individuals that manage to reach the later life stages, getting to survive, usually have a long life. These species produce many gametes to release, which results in the production of many offspring simultaneously. However, adult individuals provide no parental care. Their success in reproduction depends on the number of surviving descendants.

We might also mention that the population size is under the carrying capacity. r-strategist choose to live in areas with only a few individuals, where nitches are hardly occupied.