Explanation:
The exoskeleton and molting
The success of arthropods derives in large part from the evolution of their unique, nonliving, organic, jointed exoskeleton (see figure), which not only functions in support but also provides protection and, with the muscle system, contributes to efficient locomotion. The exoskeleton is composed of a thin, outer protein layer, the epicuticle, and a thick, inner, chitin–protein layer, the procuticle. In most terrestrial arthropods, such as insects and spiders, the epicuticle contains waxes that aid in reducing evaporative water loss. The procuticle consists of an outer exocuticle and an inner endocuticle. In the exocuticle there is cross-bonding of the chitin–protein chains (tanning), which provides additional strength to the skeletal material. The hardness of various parts of the exoskeleton in different arthropods is related to the thickness and degree of tanning of the exocuticle. In crustaceans, additional rigidity is achieved by having the exoskeleton impregnated with varying amounts of calcium carbonate.
arthropod integument
arthropod integument
Diagrammatic section through the arthropod integument.
Encyclopædia Britannica, Inc.
The formation of an exoskeleton required the simultaneous solution of two functional problems in the evolution of arthropods: If the animal is encased in a rigid covering, how can it grow and how can it move? The problem of growth is solved in arthropods by molting, or ecdysis, the periodic shedding of the old exoskeleton. The underlying cells release enzymes that digest the base of the old exoskeleton (much of the endocuticle) and then secrete a new exoskeleton beneath the old one. At the time of actual shedding, the old skeleton splits along specific lines characteristic of the group, and the animal pulls out of the old skeleton as from a suit of clothes. The old skeleton is usually abandoned but in some species is eaten. The new exoskeleton, which is soft and flexible, is then stretched by localized, elevated blood pressure augmented by the intake of water or air. Hardening occurs by stretching and especially by tanning within a number of hours of molting. In crustaceans, calcium carbonate is deposited into the new procuticle. (Soft-shell crabs are simply newly molted crabs.) Additional endocuticle may be added to the exoskeleton for some days or weeks following molting.
molting
molting
Grasshopper shedding its exoskeleton.
© Cathy Keifer/Dreamstime.com
Molting is under hormonal control, and there is a long preparatory phase that precedes the process. The steroid hormone ecdysone, secreted by specific endocrine centres and circulated in the blood, is the direct initiator of molting. The actual timing of a molt, however, is regulated by other hormones and commonly by environmental factors. The interval between molts is called an instar. Because of the frequency of molts, instars are short early in life but grow longer with increasing age. Some arthropods, such as most spiders and insects, stop molting when they reach sexual maturity; others, like lobsters and crabs, molt throughout their lives. Most of the larger spiders of temperate regions, for example, molt about 10 times before reaching sexual maturity. As a result of molting, the length and volume of an arthropod display steplike increases over the life span, but internal tissue growth is continual as in other animals.
Loss of a limb is a common hazard in the life of many arthropods. Indeed, some arthropods, such as crabs, are capable of amputating an appendage if it is seized by a predator. The limb is then regenerated from a small, nipplelike rudiment formed at the site of the lost limb. The new limb develops beneath the old exoskeleton during the premolt period and then appears when the animal molts.
Answer:
Three layers
Explanation:
Outer= Composed of proteins and lipids. Repels water and prevents desiccation in terrestrial places.
Middler=Provides primary protection
Inner=Flexibke at joints, muscles attach here.
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What process is occurring in the illustration?
a) classic ecosystem
b) climax community
c) primary succession
d) secondary succession
classic ecosystem
Explanation:
because i love
Answer: D
Secondary Succession
Explanation:
I took the quiz.
difference between blood and lymph
Explanation:
Hope this is helpful
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Blood has RBC's, WBC's, platelets and a fluid called plasma. Whereas lymph has WBC's and watery fluid. They both have immune and also circulatory functions in them. One of the major differences between them is that blood flows through blood vessels and lymph through lymphatic vessels.
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A freckled man marries a woman without freckles. They have four children, two with freckles, and two without freckles. What are the genotypes of all these people?
Answer:
The genotype of the father: Ff
The genotype of the mother: ff
The genotype of the two children without freckles: ff
The genotype of the two children with freckles: Ff
Explanation:
Freckles (F) are is dominant trait, so one dominant allele in the genotype of an individual will cause he/she to have freckles. Since the father has freckles, but only two of his children has freckles; that means that he has a heterozygous genotype. In the Punnett Square, the offsprings' genotypes are shown, as well as the parents'.
A freckled man marries a woman without freckles, and they have four children, two with freckles and two without, so the genotype of the parents are Ff, ff and the children with freckles are Ff, while the freckleless are ff types.
What is the significance of the freckle trait?There are both dominant and recessive traits that determine the person's quality, such as freckles, which are dominant over being freckleless. When the parents with freckles cross with the parents without freckles, they will produce half the freckles and half the freckleless. The parent with a freckle is heterozygous (Ff), so two types of gametes will be produced, such as F and f, and will form Ff and ff offspring when crossed with the freckleless parent (ff).
Hence, a freckled man marries a woman without freckles, and they have four children, two with freckles and two without, so the genotype of the parents are Ff, ff and the children with freckles are Ff, while the freckleless are ff types.
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Summarize the differences between early succession, mid-succession, and late succession?
Certain mental problems are thought to be caused by not having enough
neurotransmitters. Why would a lack of neurotransmitters cause problems?
A. Neurons would not be able to receive sensory messages.
B. Neurotransmitters send signals from neuron to neuron.
C. Neurons would not be able to grow longer.
D. Neurons would not be able to move to new areas.
Answer:
B. Neurotransmitters send signals from neuron to neuron.
Explanation:
Lack of neurotransmitters may cause problems because neurotransmitters send signals from neuron to neuron.
The lack of neurotransmitters cause problems because neurotransmitters send signals from neuron to neuron. Therefore, option (B) is correct.
A neurotransmitter is a molecule that a neuron secretes to influence another cell at a synapse. Another neuron, a gland or muscle cell, or the target cell, could be the cell that receives the signal.
Your body cannot function without chemical messengers called neurotransmitters. Chemical signals, or "messages," are carried from one neuron (a nerve cell) to the next target cell by them. The following objective cell can be another nerve cell, a muscle cell or an organ.
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Which event came first? The age of reptiles Amphibians leave the water Trilobites are one of the dominant species on Earth Early humans arise on Earth
Answer:
Trilobites are one of the dominant species on Earth
We know it's not D, the age of reptiles was just a "wee" bit before humans, and amphibians came after trilobites.
Answer
F1 development of the ozone layer
S2 sharks and trilobites abundant in oceans
T3 plants and animals colonize land
F4 dominance of reptiles >> dominance of mammals
Many research studies have shown that different species may possess some of the exact same genes but show vastly different traits. How can that happen?
Answer:
Mutation can occur or the order in which these genes appear are in different order. Genetic variation can also occur.
Please help ;(
question and answer options in photo
zoom in if needed
Thank You :D
Answer:
B Decomposers
Explanation:
There is nothing to eat the dead animals/ leaves for when they die
Answer:
I believe the answer is, B
Easy question about plant water loss?
Answer:
B,C,F
Explanation:
give a reason why eggs shell is porous
Answer:
if it's porous it must absorb stuff
Explanation:
like a napkin
Answer:
Explanation:Directly under the chicken egg's shell are two membranes. When the eggs are laid by the mother they are warmer than the air, and as they cool the material inside the egg shrinks a little bit. ... The tiny pores in the shell allow the carbon dioxide to escape and fresh air to get in.
Can someone plz help me on this science its due today and STAAR test is next week
Answer:
answer is c
Explanation:
hope it helps!!!
The pH of a solution is a measure of how acidic or basic it is. The greater the pH, the more basic the solution is. Corals and other marine invertebrates require less energy to make their exoskeletons and shells when ocean water is slightly basic. As carbon dioxide concentrations in Earth’s atmosphere rise, ocean water absorbs carbon dioxide and becomes more acidic. This process is called ocean acidification. How do you think ocean acidification will affect the coral reef?
Explanation:
Because coral reefs have limestone (calcium carbonate), the coral reefs will be greatly affected. The increase in hydrogen ions in the ocean will corrode the coral reef, making it inhabitable for species. This will affect the crabs that get their food and the community that lives within in it. Making countless of species to loose their lives and their way if living.
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Answer:
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Explanation:
An airplane flies from Minneapolis to Chicago in 62 minutes.
If it is 572,000 meters from Minneapolis to Chicago, what is the plane's average speed?
A. 2,000 m/s
B. 355 m/s
C. 154 m/s
D. 119 m/s
Answer:
154m/s
Explanation:
Average speed= distance(m)/time(sec)
Distance=572,000metres
Time=62×60=3720seconds
As=572000/3720=153.76aproximately154m/s
A substace put in a space or cantainer to fill it, usually applied in wood to fill up cracks and grooves
Answer:
Glue and sawdust.
Explanation:
Glue and sawdust are the substances that applied in wood to fill up cracks and grooves. You can use the glue and sawdust method to fill the gaps present in the wood. This method is a quick and easy solution that successfully fill up the gaps and grooves on the wood. The method of using this method is, first fill the gap with a small amount of wood glue, then rub sawdust into the gap which attached the saw dust with itself and the gaps are filled.
Negative feedback loops:
a. decrease rate
b. increase rate
c. reverse change
d. reinforce change
Answer:
the answer would be c
Explanation:
hope it helped
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2.ighdf
3.ygf
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Answer:
1.Law of conservation of energy
2. Energy transformation
3.Friction
4. electric, thermal
5. Kinetic, Potential
6. Potential, Kinetic
7.Kinetic
8.Radiant, electrical
9. Electrical
10. Radiant
Why do your mitochondria come from your mom?
Answer:
the mitochondria in mammalian sperm are usually destroyed by the egg cell after fertilization.
Explanation:
explain reproduction in snail
Fossils and Evolution On Study Island
A team of scientists are studying three different layers of sedimentary rock to learn about a particular reptile species. In the layer of rock that is closest to the Earth's surface, the reptiles' teeth fossils are found to be short and straight. In the layer below, the reptiles' teeth fossils are found to be long and straight. In the layer below that, the reptiles' teeth fossils are found to be long and curved.
Based on this information, the reptiles today most likely have
A.
long, straight teeth.
B.
no teeth.
C.
long, curved teeth.
D.
short, straight teeth.
Answer: short, straight teeth
Explanation: study island
All of Earth's biomes considered together represent:
A. population
B. community
C. biosphere
D. ecosystem
All of Earth's biomes considered together represent biosphere.
What is a biome?A biome is an amalgamation of plants and animals with similar traits for their habitat. Biomes can be found in many different locations. They are biological communities that have developed as a result of the area's common physical climate.
What is a biosphere?The biosphere is a small area of the earth's surface where soil, water, and air work together to support life. Only in this region is life possible.
What is a population?A population is a collection of people who can interbreed, share resources, or compete with one another for those resources.
What is a community?A community is defined as a collection of individuals belonging to various species who reside in the same region.
What is an ecosystem?An ecosystem is a biotic and abiotic component-based functioning unit of nature. Air, water, and soil are examples of abiotic components. The biotic components are producers, consumers, and decomposers.
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What does biodiversity mean ?
Answer:
biodiversity mean Biodiversity, also called biological diversity, the variety of life found in a place on Earth or, often, the total variety of life on Earth.
Explanation:
Answer: Biodiversity is a term used to describe the enormous variety of life on Earth. It can be used more specifically to refer to all of the species in one region or ecosystem. Biodiversity refers to every living thing, including plants, bacteria, animals, and humans.
Explanation: Usually three levels of biodiversity are discussed—genetic, species, and ecosystem diversity.
Genetic diversity is all the different genes contained in all individualplants, animals, fungi, and microorganisms. It occurs within a species as
well as between species.
Species diversity is all the differences within and between populationsof species, as well as between different species.
Ecosystem diversity is all the different habitats, biological communities,and ecological processes, as well as variation within individual ecosystems.
Which of the following is not a benefit to humans from biodiversity?
A. Many medications are made from living organisms
B. Enjoyment from recreational activities
C. We have a variety of products produced for clothing, food, and other items
D. The weather is more comfortable
For me it's letter A.
Because B and C and D are benefits of biodiversity....So that's why,for me it's letter A.
Well,don't trust me if you don't want to
Which type of tree ends up dominating many landscapes over time because they will slowly make it harder for other types of trees to grow?
Question 5 options:
Shrubs
Conifer
Deciduous
Grasses
Answer: conifer
Explanation: I took a test with the same question and I got it right but other than that I have no explanation
Answer: conifer
Explanation: i took the quiz and got it right
hope it helps:)
Plz help ASAP!! No links or files or you’ll be reported.
Answer: Nephrons eliminate glucose and other waste from the body or option C.
limestone can be a very jointed type of rock. which drainage pattern would you expect to see as a result
The drainage pattern one is expected to see in the limestone is trellis. The correct option is C.
What are trellis drainage pattern?Trellis drainage patterns form when sedimentary rocks like limestone are rolled up or slanted and then stripped away to varying degrees depending on their strength.
The Rocky Mountains of British Columbia and Alberta are prime examples of this, with trellis patterns found in many of the drainage systems.
Thus, the correct option is C.
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The missing options of the question are:
A. DendriticB. RadialC. TrellisD. RectangularDoes grain size determine the porosity of a sediment type?
Answer:
Yes
Explanation:
In sediments or sedimentary rocks the porosity depends on grain size, the shapes of the grains, and the degree of sorting, and the degree of cementation. Well-rounded coarse-grained sediments usually have higher porosity than fine-grained sediments, because the grains do not fit together well
distinguish between absorption and reabsorption in the mammalian body
Answer:
Tubular reabsorption is the process that moves solutes and water out of the filtrate and back into your bloodstream. This process is known as reabsorption, because this is the second time they have been absorbed; the first time being when they were absorbed into the bloodstream from the digestive tract after a meal.
Explanation:
Which of the following mechanisms is the correct sequence of events that takes place during the plant responses to internal and external signals?
A) transduction, reception, and response
B) reception and transduction
C) reception, transduction, and response
D) reception and response
Answer:
C) reception, transduction, and response
Explanation:
Plant signaling means that information is conveyed from receptor systems to effectors within and between plant cells.
Signals can be of chemical form or electrical form.
Plant responses to internal and external signals take place in the following sequence:
Reception
Transduction
Response
So, option C) is correct
Alice wanted to see if a new premium gasoline would give her more kilometres per litre. She filled her car with the new gasoline and went on a long trip. When she calculated her mileage, she discovered that she has gone 40 kilometres further on this tank of gas than she went on a tank of regular gas when she was driving around town as usual. She decided to buy the premium gas from then on to get better mileage. What are the errors in this experiment?
Answer:
She didn't cover the same distance for the new premium gasoline and regular gas
Explanation:
