1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Mumz [18]
3 years ago
9

Heyy! please help mee. This is missing and I need it turned in asap!

Biology
1 answer:
Over [174]3 years ago
8 0

Answer:

Living things are highly organized and structured, following a hierarchy that can be examined on a scale from small to large. The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules. A molecule is a chemical structure consisting of at least two atoms held together by one or more chemical bonds. Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules). An example of a macromolecule is deoxyribonucleic acid (DNA) (Figure 1), which contains the instructions for the structure and functioning of all living organisms.



Figure 1. All molecules, including this DNA molecule, are composed of atoms. (credit: “brian0918″/Wikimedia Commons)

Some cells contain aggregates of macromolecules surrounded by membranes; these are called organelles. Organelles are small structures that exist within cells. Examples of organelles include mitochondria and chloroplasts, which carry out indispensable functions: mitochondria produce energy to power the cell, while chloroplasts enable green plants to utilize the energy in sunlight to make sugars. All living things are made of cells; the cell itself is the smallest fundamental unit of structure and function in living organisms. (This requirement is why viruses are not considered living: they are not made of cells. To make new viruses, they have to invade and hijack the reproductive mechanism of a living cell; only then can they obtain the materials they need to reproduce.) Some organisms consist of a single cell and others are multicellular. Cells are classified as prokaryotic or eukaryotic. Prokaryotes are single-celled or colonial organisms that do not have membrane-bound nuclei or organelles; in contrast, the cells of eukaryotes do have membrane-bound organelles and a membrane-bound nucleus.

In larger organisms, cells combine to make tissues, which are groups of similar cells carrying out similar or related functions. Organs are collections of tissues grouped together performing a common function. Organs are present not only in animals but also in plants. An organ system is a higher level of organization that consists of functionally related organs. Mammals have many organ systems. For instance, the circulatory system transports blood through the body and to and from the lungs; it includes organs such as the heart and blood vessels. Organisms are individual living entities. For example, each tree in a forest is an organism. Single-celled prokaryotes and single-celled eukaryotes are also considered organisms and are typically referred to as microorganisms.

All the individuals of a species living within a specific area are collectively called a population. For example, a forest may include many pine trees. All of these pine trees represent the population of pine trees in this forest. Different populations may live in the same specific area. For example, the forest with the pine trees includes populations of flowering plants and also insects and microbial populations. A community is the sum of populations inhabiting a particular area. For instance, all of the trees, flowers, insects, and other populations in a forest form the forest’s community. Keep in mind that the community level only consists of living organisms. The forest itself is an ecosystem; this is the first level that contains non-living aspects of a given area that impact the living things in that environment. An ecosystem consists of all the living things in a particular area together with the abiotic, non-living parts of that environment such as nitrogen in the soil or rain water. At the highest level of organization (Figure 2), the biosphere is the collection of all ecosystems, and it represents the zones of life on earth. It includes land, water, and even the atmosphere to a certain extent.

You might be interested in
Both the hair and skin contain keratin. When comparing the hair shaft to the skin which layer of the epidermis is most similar?
Paha777 [63]

Answer:straum and straum

Explanation:

they both have the same name

3 0
2 years ago
List two characteristics of aquatic animals.​
VladimirAG [237]
1.Most aquatic animals have fins or paddles that help them swim
2. Skin is usually slippery and soft
3 0
3 years ago
write a paragraph explaining why it is difficult to make drugs or vaccines against HIVgiven the fact that each time reverse tran
Sunny_sXe [5.5K]

Answer:

people who are HIV positive but keep the virus in check. This research stems from the International HIV Controllers Study, and researchers hope that their findings will ultimately help inform the development of new therapies and vaccines. Over the last 30 years, scientists have discovered lots of tantalizing clues about the virus, our immune system, and the interplay between the two, but a vaccine remains elusive.

Since the epidemic emerged, 25 million people have died from AIDS and 60 million have been infected with HIV, according to the Joint United Nations Programme on HIV/AIDS. AIDS was detected in California and New York in 1981, first among gay men and drug users, then in hemophiliacs who had received blood transfusions, and later in non-drug-using men, women, and children

Initially, little was known about how AIDS was transmitted, and even less was known about the virus that caused it. In 1985, the virus itself was isolated. Following this discovery, Margaret Heckler, the US Human Services Secretary at that time, famously declared, "We hope to have a vaccine [against AIDS] ready for testing in about two years."

Vaccines have worked well against once widespread diseases like smallpox and polio. After the AIDS virus was found, many people, including many scientists, thought AIDS would be added to the list. Vaccines mimic natural infections, during which the body produces antibodies that kill the virus. But unlike smallpox or polio, HIV doesn’t stimulate this kind of response – our immune systems are generally blind to the virus and unable to launch an effective antibody attack. Other challenges that scientists face as they try to create a vaccine include a lack of good animal models to study and the virus's ability to constantly change and mutate. Additionally, although controllers can keep levels of the virus low, no one has ever fully recovered from HIV infection. This means there's no natural, winning strategy for scientists to study and try to elicit.

Results from previous efforts to build a vaccine have been disappointing. Last year, an HIV vaccine trial in Thailand produced unimpressive results – by some measures, the vaccine reduced the chances of infection by 30 percent at most.

But this summer, scientists discovered three powerful antibodies against HIV and efforts are now underway to transform this discovery into treatment.

In addition to approaches that try to stimulate antibody immunity, researchers are also looking for ways to stimulate cellular immunity, or activate the other weapons in the immune system’s arsenal, like macrophages, natural killer cells, T cells, and more. Alerting the body’s immune system to HIV’s invasion may not prevent infection, but it could inhibit the disease’s progression and keep viral populations so low that there might be less risk of transmission.

One vaccine developed using this approach failed in trials, appearing to even increase some participants' susceptibility to the virus. But knowledge of what happened in that trial may help scientists create a more effective vaccine that targets cellular immunity

By looking at the interaction between the virus and hosts who are able to hold the virus at bay without the help of medicine, researchers hope to learn more about how to fight the virus. New clues from the viral and host genome may help lay a foundation for future means of combating HIV.

Explanation:

4 0
2 years ago
What do Ice crystal in meat signifying
vladimir2022 [97]

Explanation:

Ice crystals in meat signify that it is frozen,a bunch of water molecules within the food form to keep the meat hydrated .

I hope it's helpful!

6 0
3 years ago
The nurse is monitoring a​ 2-year-old client with cellulitis that developed from an insect bite on the face. The nurse understan
Amanda [17]
An insect bite on the face produces a break in the skin which introduces the normal skin flora (usually <em>Staphylococcus </em>and <em>Streptococcus</em>) to the sterile subcutaneous tissue causing inflammation. The inflammation of the subcutaneous tissue is called cellulitis. Since the infection is in the face, then it can travel from the infected site to the meninges through the cavernous sinuses and cause bacterial meningitis. 
8 0
3 years ago
Other questions:
  • In what phase of mitosis do the chromosomes line up along the equator of the cell ?
    12·1 answer
  • Which of the following is NOT a function of the upper respiratory tract?
    5·1 answer
  • Can someone explain to me in depth the difference between covalence and ionic bonds
    10·1 answer
  • Is RNA a nucleic acid that helps build proteins
    13·1 answer
  • If there is a mutation, and the wrong amino acid is put into sequence, what is the result?
    8·1 answer
  • The water cycle occurs almost exclusively in which layer of our atmosphere?​
    12·2 answers
  • Once meiosis occurs gametesare formed with a reduced number of chromosomes.the gametes are described as being
    11·1 answer
  • ) You ran your 5kb DNA sample on the gel and you notice that the size of the fragment seems to be smaller than 5kb. You then tre
    6·1 answer
  • LIST THREE NATURAL PROCESS THAT AFFECT THE ECOSYSTEM
    14·1 answer
  • ASAP DIS IS LATE PLS ASAP o(≧口≦)o
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!