unit 1 lesson 2-4

Question 1

organ system

Answer 1

two or more organs that work in a coordinated way to carry out similar functions

Question 2

organ

Answer 2

group of different types of tissues that work together to perform a specific function or related functions

Question 3

tissue

Answer 3

is a group of similar cells that work together to perform a specialized function, usually as part of an organ.

Question 4

human body, organs are made up of four general types of tissues—

Answer 4

epithelial, connective, muscle, and
nervous tissue.

Question 5

cell

Answer 5

the most basic unit of life

Question 6

Cell differentiation

Answer 6

is the process by which cells become specialized in structure and function.

All cells in a multicellular organism arise from a single cell. As the organism develops, cells take on unique structures that help them carry out specialized functions.

Question 7

the nervous system and neurons

Answer 7

The nervous system is a network of nerves and sensory organs that work together to process information and respond to the environment. The basic unit of the nervous system is the neuron. Neurons are specialized cells that are able to send electrical and chemical signals to help the organism sense information, coordinate a response, and carry out that response.

Question 8

Humans and other organisms have three types of neurons:

Answer 8

sensory neurons, interneurons, and motor neurons. Sensory neurons detect stimuli and send signals to the brain and the spinal cord. Interneurons in the brain and spinal cord receive and process the information from the sensory neurons and send response signals to motor neurons. Motor neurons act on the signal by stimulating muscles to contract.

Question 9

Most neurons have three main parts:

Answer 9

the cell body, one or more dendrites, and an axon.

extra info
The short, branch-like extensions that extend from the cell body are called dendrites. Dendrites receive electrochemical messages from other cells. The axon is a long extension of the cell that carries electrochemical signals away from the cell body and passes them to other cells. The branched endings of the axon are specialized to transmit electrochemical signals to other cells.

Question 10

how dose The nervous system interact with all the other systems in the body.

Answer 10

For example, when you eat, your brain signals your digestive system to start making chemicals and churning your food. Neurons also stimulate muscle tissue in the digestive system to contract, which helps the digestive system move and break down food.

Question 11

Muscles

Answer 11

consist of bundles of muscle cells that contract when they are stimulated by the nervous system. A contraction shortens the muscle, causing the bone or tissue to which the muscle is attached to move.

Question 12

voluntary control vs involuntary control

Answer 12

Some muscles are under voluntary control, so you can choose to move this type of muscle.

Some muscles are under involuntary control, meaning they move in response to nerve signals or hormones, but you do not choose to move them.

Question 13

Osmoregulation

Answer 13

maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.

Question 14

myofibril

Answer 14

Muscle fibers are bundles of single, thin muscle cells called myofibrils.

Question 15

sarcomeres

Answer 15

Each myofibril is made up of several sarcomeres. A sarcomere is the contractile unit of the muscle cell.

Question 16

cell membrane

Answer 16

double layer of phospholipids that forms a boundary between a cell and the surrounding environment and controls the passage of materials into and out of a cell

Question 17

Cytoplasm

Answer 17

is a jelly-like substance that contains dissolved materials such as proteins and sugars. These building blocks are used to make cell structures and can be broken down to release energy used by the cell to do work

Question 18

organelles

Answer 18

which are specialized structures that perform distinct processes within a cell.

Question 19

Prokaryotic

Answer 19

cells do not have a nucleus or other membrane-bound organelles. Instead, the cell’s DNA is suspended in the cytoplasm. Most prokaryotes are microscopic, single-celled organisms

Question 20

Eukaryotic

Answer 20

cells have a nucleus and other membrane-bound organelles. Eukaryotes may be multicellular or single-celled organisms.

Question 21

cytoskeleton

Answer 21

gives a cell its shape while at the same time maintaining its flexibility. It is made of small subunits that form long threads, or fibers, that crisscross the entire cell.

Question 22

nucleus

Answer 22

organelle composed of a double membrane that acts as the storehouse for most of a cell’s DNA

Question 23

endoplasmic reticulum

Answer 23

ER, is an interconnected network of thin, folded membranes. Numerous processes, including the production of proteins, occur both on the surface of the ER and inside the ER.

Question 24

ribosomes

Answer 24

tiny organelles that help make proteins.

Question 25

Golgi apparatus

Answer 25

Golgi apparatus consists of stacks of membrane-enclosed spaces that process, sort, and deliver proteins. Its membranes contain structures called enzymes that make additional changes to proteins. The Golgi apparatus also packages proteins. Some of the packaged proteins are stored within the Golgi apparatus for later use.

Question 26

mitochondrion

Answer 26

bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA

Question 27

Lysosomes

Answer 27

Lysosomes are membrane-bound organelles that contain special proteins called enzymes. These enzymes break down and recycle old, worn-out cell parts.

Question 28

Centrioles

Answer 28

Centrioles are involved in cell division, and they will be discussed in further detail in another lesson.

Question 29

Vacuole

Answer 29

vacuole is a fluid-filled sac used for the storage of materials needed by a cell. These materials may include water, nutrients, and salts

Question 30

Homeostasis

Answer 30

regulation and maintenance of constant internal conditions in an organism

Question 31

Process of homeostasis

Answer 31

Stimulus causes imbalance, stimuli detected by receptors, receptor sends info to control center, control center compares vs set points, if away from set points control center sends message through communication system, effectors get message and carry out response, response restores balance

Question 32

stimulus

Answer 32

something that causes a physiological response

Question 33

hormone

Answer 33

chemical signal that is produced in one part of an organism and affects cell activity in another part

Question 34

feedback loop

Answer 34

information that is compared with a set of ideal values and aids in maintaining homeostasis

Question 35

negative feedback loop

Answer 35

control system for homeostasis that adjusts the body’s conditions when the conditions vary from the ideal

In a negative feedback loop, a stimulus causes an imbalance in one direction. This imbalance is detected by receptors that send information to the control center. The control center evaluates the information and sends a signal to the effectors to make an adjustment that is in the opposite direction from the stimulus, returning the system to balance.

Question 36

positive feedback loop

Answer 36

control system in which sensory information causes the body to increase the rate of change away from homeostasis

Question 37

How does a feedback loop keep blood-pressure in homeostasis

Answer 37

Blood pressure is the force with which blood pushes against the walls of blood vessels. Receptors in the blood vessels and heart detect changes in blood pressure, then signal the brain. The brain stimulates the heart to beat faster or slower to help restore the blood pressure to its correct level.

Question 38

explain glucose feedback loop

Answer 38

Blood glucose low
receptors detect change
pancreas releases Glucagon
Liver breaks down glycogen and releases glucose
blood glucose rises

blood glucose high
receptors detect change
pancrease releases insulin
body cells take up glucose or liver stores it
blood glucose drops

Question 39

How is homeostasis disrupted

Answer 39

failure of sensors to detect a change in the internal or external environment, sending or receiving the wrong message, serious injury, or disease-causing agents, such as bacteria or viruses

Question 40

stomata

Answer 40

Gases are exchanged through structures called stomata (singular, stoma). Stomata are small openings, or pores, on the underside of leaves that are surrounded by cells called guard cells. Stomata can be open or closed, depending on the needs of the plant.

Question 41

abscisic acid

Answer 41

To counteract this, many types of plants release a hormone called abscisic acid, or ABA, from the roots in response to decreased soil water levels. The accumulation of ABA in leaves triggers the transport of water out of the guard cells. This causes the cells to relax, closing the stomata.

Question 42

Osmoregulation

Answer 42

If you live in fresh water, your body acts like a permanently thirsty sponge. Saltwater and freshwater fish have developed strategies to cope with these problems. As part of those prevention strategies, both types of fish undergo a homeostatic process called osmoregulation, which balances fluid and salt levels.

Question 42

Thermoregulation

Answer 42

maintains a stable body temperature under a variety of conditions. Sometimes, the response to a temperature imbalance is a change in behavior. This type of feedback response is how cold-blooded animals, or ectotherms, manage their body temperature.

Question 43

technology

Answer 43

The application of science for practical purposes; the use of tools, machines, materials, and processes to meet human needs

Question 44

bioengineering

Answer 44

the application of engineering concepts to living things

Question 45

biotechnology

Answer 45

use and application of living things and biological processes

Question 46

research and development

Answer 46

Scientists ask questions to learn more about a phenomenon, and engineers design solutions to problems related to that phenomenon. This back-and-forth between scientists and engineers is part of a process known as research and development. The studies and testing performed during this process often lead to the development and improvement of technologies.

Question 47

engineering design process

Answer 47

a series of steps that engineers follow to come up with a solution to a problem

define the problem
research
define problem in terms of criteria and constraints
brainstorm solutions
evaluate solutions with respect to constrains
choose one or two solutions for testing
develop test model
Does the solution meet criteria
redefine problem if needed to clarify more important criteria
consider tradeoffs
build and test a prototype
refine the solution
is this the best solution in the budget or time?

Question 48

What types of information can be gained from building a prototype

Answer 48

Many tests can be run on the functionality of certain features of the design without using expensive materials.
A prototype could be brought to the client for approval and input before designs are finalized.
Prototyping can tell you if components on your design are not needed or could be built more efficiently.