(20 points) me out with this assignment (7th grade, science, tectonic plates 20 points) (you dont have to do it all but i would really appreciate people telling the answers)
1. seafloor spreading occurs at which of the following plate boundaries?
a. transform fault
b. convergent collision
c. convergent subduction
d. divergent

2. convection currents in earth's mantle
a. transfer heat from earth's interior to its surface
b. transfer heat from earth's surface to its interior
c. cause radioactive decay to occur in the mantle
d. are caused by plate movement

3. earth's outer layers are broken into pieces called
a. plate tectonics
b. mid-ocean ridges
c. lithospheric plates
d. slabs

4. as the temperature of a region of the mantle increases, it
a. becomes less dense
b. becomes more radioactive
c. becomes more dense
d. sinks

5. what was wegener's continental drift hypothesis rejected when he first proposed it?
a. he had made mistakes in dating his rocks and fossils
b. wegener's evidence was better explained by the seafloor spreading hypothesis
c. no forces were known at that time that could cause continents to move.
d. his fossils evidence was incomplete.

6. which was not evidence presented by alfred wegener to support his hypothesis of continental drift?
a. the distribution of certain fossils
b. the geographic fit of the continents
c. locations of mountain ranges and rock types
d. reversals of earth's magnetic polarity

7. the hypothesis that continents have slowly move to their current locations is called what?
8. a series of processes known as the slowly changes rocks from one kind to another kind
9. the lithosphere is broken into sections called which float on top of the asthenosphere.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!

question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.  

for example:  

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer.   you start to feel bad.

anthropod traits:

a well-developed collarbone

rotating shoulder joints

partially rotating elbow joints

opposable thumb

similar dental formula