Help me!!!!
It's 7th grade science

Cells are small in size because it is very important that they have a surface area to volume ratio that would allow adequate intake of food nutrients, as well as the excretion of waste materials.

A cell can be defined as the fundamental (basic), functional, structural and smallest unit of life found in all living organisms.

According to cell type, living organism are mainly divided into two (2) main groups and these are;

It is very important that the surface area to the volume ratio of cell is small, so as to allow enough materials such as food, move through the cell membrane quickly for the survival of the cell.

Hence, cells are small in size because it is very important that they have a surface area to volume ratio that would allow adequate intake of food nutrients, as well as the excretion of waste materials.

In conclusion, the smaller a cell, the larger would be its surface area to volume ratio.

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Answer:Kidney

Explanation:

The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system.

An organs Kidney, ureter, urinary bladder and urethra are part of the excretory systems.

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Answer:

t

Explanation:

its recessive

Answer:

is c

Explanation:

the breakup of glucose into two pyruvate molecules. the maltose lands on the active site of the enzyme. the enzyme has to have a specific in order for the maltose to connect there.

Answer:

# Diffusion is a down hill process.(flow is from higher concentration to lower concentration)

# It does not require energy.

but,

# Active transport is a uphill process.(flow is from lower concentration to higher concentration)

# It requires energy.

Two features of diffusion that do not apply to active transport are:

Diffusion is a process by which molecules move from an area of high concentration to an area of low concentration, until they reach a state of equilibrium where there is no further net movement of molecules.

This occurs because molecules are in constant random motion, and they will naturally move from areas where they are more concentrated to areas where they are less concentrated. This process does not require energy input, and it will continue until the concentration of molecules is the same throughout the system.

Active transport, on the other hand, is a process by which molecules are moved across a membrane against their concentration gradient, from an area of low concentration to an area of high concentration.

This process requires energy in the form of ATP, which is used to pump molecules or ions against their concentration gradient. Active transport is able to move molecules or ions against their concentration gradient because it uses energy to change the shape of transport proteins in the membrane, allowing them to move molecules against their concentration gradient.

Therefore, two key features of diffusion that do not apply to active transport are that diffusion is a passive process that does not require energy input, while active transport requires energy input in the form of ATP.

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Invasive species are the species which come and occupy the area and the habitat is lost when once they invade the habitat. Some of the examples of invasive species are asian carp and cane toad with many more.

When one species that invade the habitat and ends up the habitat of that particular area that is called as eutrophication and with that what happens is that the organisms which are living there ends up.

Ten most common of the world's invasive species are written as following :

1. Asian Carp.

2. Zebra Mussel

3. Cane Toad

4. European Starling

5. Kudzu

6. Asian long-horned beetle

7. Small Indian mongoose

Water hyacinth that is the terror of Bengal was once a decorative plant but when it was introduced to the water resources then at that time they multiplied to this extent that the species got automatically distinct from the water bodies.

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Answer:    A conserved set of cyclin-dependent protein kinases (Cdks) initiate or regulate events through phosphorylation of intracellular proteins, thus controlling cell cycle progression, terminal differentiation, and apoptosis.

Explanation: Your welcome! ;D

Answer:

The correct answer is- water droplet found on a spider web in the morning

Explanation:

Hope this helps u

Crown me as brainliest

Answer:

A semi-permeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of the egg.

Explanation:

An example of a biological semi-permeable membrane is the lipid bilayer, on which is based on the plasma membrane that surrounds all biological cells. A group of phospholipids (consisting of a phosphate head and two fatty acid tails) arranged into a double layer, the phospholipid bilayer is a semipermeable membrane that is very specific in its permeability. The hydrophilic phosphate heads are in the outside layer and exposed to the water content outside and within the cell. The hydrophobic tails are the layer hidden in the inside of the membrane. The phospholipid bilayer is most permeable to small, uncharged solutes. Protein channels are embedded in or through phospholipids, and, collectively, this model is known as the fluid mosaic model. Aquaporins are protein channel pores permeable to water. Information can also pass through the plasma membrane when signaling molecules bind to receptors in the cell membrane. The signaling molecules bind to the receptors, which alters the structure of these proteins. A change in the protein structure initiates a signaling cascade. The G protein-coupled receptor signaling provides is an important subset of such signaling processes.

Answer: Dominant

Explanation: If the trait is dominant, one of the parents must have the trait. Dominant traits will not skip a generation. If the trait is recessive, neither parent is required to have the trait since they can be heterozygous. Determine if the chart shows an autosomal or sex-linked (usually X-linked) trait.

Answer:

50%

Explanation:

This question involves a gene coding for seed shape. The allele for round seeds (R) is dominant over the allele for wrinkled seeds (r). A heterozygous plant (Rr) will therefore be round seeded.

If a plant that is heterozygous for seed type (Rr) is crossed with one that has only wrinkled seeds (rr), the following gametes will be produced by each parent:

Rr - R and r

rr - r and r

Using these gametes in a punnet square (see attached image), the following offsprings will be produced: Rr, Rr, rr and rr

Rr - Round seeds

rr - wrinkled seeds

1 out of 2 offsprings will be possess wrinkled seeds i.e. 1/2 × 100 = 50%.

Answer:

a sediments  becoming pressed or cemented together

Explanation:

Answer:

a

Explanation:

Answer:

The correct answer is - The point closest to the scalp.

Explanation:

In order to analyze a strand of hair investigators need to collect the DNA. To analyze a strand of hair the DNA must be nuclear DNA which can be found at the root of the hair near the scalp as the point, hair attached to the scalp there are cells that can provide the nuclear DNA. Any other section or the part of the hair strand does not contain the nuclear DNA so analyze DNA would not be possible.

Answer:

Millions of years from now, paleontologists may dig into Earth and uncover fossils from our own time. They may, like scientists today, construct a chronology of what came before them, watching past species popping into—and later out of—existence. Today, humans are continually driving species to extinction—by one estimate, almost 500 vertebrate species have gone extinct in the past 100 years—but will those future scientists be able to tell? New research suggests that it might not be easy: Only a small proportion of these human-caused extinctions will leave behind a fossil trace—and the most threatened species are the ones least likely to be preserved for posterity.

The history of life on Earth is punctuated by what researchers call the “Big Five” mass extinctions, a group that includes the dinosaur-killing Cretaceous-Tertiary extinction and several other, even more severe, events. Many scientists now want to add a sixth: the one that humans are causing all over the globe today. But it’s hard to gauge just how severe the current extinction crisis is, compared with others in Earth’s sometimes tumultuous history. Modern extinctions are documented, sometimes in real time. But the Big Five are measured using only the fossil record, a history of those species that were buried and preserved by sediments over time.

That’s why Roy Plotnick, a paleontologist at the University of Illinois, Chicago, and lead author of the study, thinks about far-flung scenarios involving future paleontologists. “We really need to look at modern day extinctions as if they were in the fossil record already, in order to make a comparison,” he says. So he and his colleagues searched fossil databases for modern mammal species—both those threatened by extinction and those that aren’t—to see how many modern extinctions would be detectable by relying only on fossils.    

Explanation:

Answer:

The ratios of thymine and adenine were similar, as were the ratios of guanine and cytosine.

Explanation:

deoxyribose + phosphate group + thymine

Answer:

C

Explanation:

Answer:

D.) Two nucleotide strands wound in a double helix.

Explanation:

Their model shows that DNA is composed of two double strand of nucleotide which are twisted around each other and run in antiparallel direction. the phosphate group and pentose sugar are present on outside, while nitrogenous base is present on inside

Answer:

Franklin produced an image containing "two strands twisted with double helix and phosphate back bone with base pairs".

Watson and Crick taken the x-ray image created by Franklin which lead to discovery of accurate model of  shape of DNA.

.

Explanation:

2020

Answer:

A) a feature of the landscape

Explanation:

got it right on edge

A landform is the set of forms that stand out on a plane or surface, being a feature of the landscape.

It is an outstanding texture of a surface that has different variations, among the most characteristic reliefs of the earth's surface are mountains, plateaus and plains.

These textures are presented in the form of irregularities and unevenness within a terrestrial or aquatic ecosystem, which provides a feature in a given landscape.

Therefore, we can conclude that a landform is formed by everything that protrudes from a flat surface or that modifies it, that is, it is the set of irregularities or features of a landscape.

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Answer:

The only way a phenotype or genotype can be recessive is if both alleles are recessive

Explanation:

i think

Answer:It helps an organism reproduce and therefore appears more often. And since dominant alleles sometimes are heterozygous, even if an organism with the dominant gene was able to reproduce, it could still produce a recessive offspring. So I would say that the gene that helps the organism reproduce would actually be the more prevalent trait

Explanation:

Answer:

sunlight is essential for normal growth of pine trees

Explanation:

I think becuase photosyinthiesis needs sunlight to be able for the trees to grow

i hope this helps

Answer:

c

Explanation:

cuse steel is an alloy which is a mixture of a metal and non metal

Answer:

I think it’s NADH

Explanation:

Answer:

Well, it can be both.

Explanation:

So for the parents and grandparents, It can be a genetic thing. Where your previous family members have had it and have passed it down. And for the environment thing, well, somethings can cause heart diseases like a disease on a wild animal or a foreign plant or drug can make your heart get a disease.

Answer:

x- axis

Explanation:

x- axis is left to right, the run

y- axis is up to down, the rise

Answer:

The 'run' goes through the x-axis(horizontally). It can either go left or right depending on the direction of the slope.

Answer:

See explanation

Explanation:

I will try to explain each point mentioned to the best of my ability.

The dissolution of calcium chloride in water is endothermic hence more solute dissolves as the temperature increases. When the solution cools, the solubility of the solid also decreases with decreasing temperature hence the solid reappears.

When soda is heated, carbon dioxide gas is evolved thereby decreasing the amount of dissolved carbon dioxide.

Let me state that increase in volume of solvent increases the amount of solute that can dissolve in it. This is why 250ml volume of solvent can dissolve more solute than 100ml of solvent.

Also, temperature is an important factor when discussing the solubility of a solute. This is why the temperature at which a certain value of solubility is quoted must be indicated. For solids, solubility increases with increase in temperature.

Lastly, the solubility of sodium chloride is independent of temperature. This is clearly seen by plotting a solubility curve.