bio quiz #1: cells

how does cellular differentiation allow a multicellular organism to carry out complex functions

cell differentiation causes cells with related functions to form tissues which ultimately organize into organs

reproduction

cells divide to produce new cells; unicellular organisms divide to produce a genetically identical daughter cell

explain what is meant by a generalized cell

cells that are generalized are cells that contain organelles of all cells present regardless of specialization and location

growth

cells undergo division as well as increase in size

name and describe one structure or organelle present in generalized animal cells but absent from plant cells

centrioles- associated with nuclear division in animal cells, microtubular structures

identify the organelle that is found in stems and leaves

chloroplast

nucleus

contains and protects genetic material (DNA)

describe the features of the liver cell that make it relatively unspecialized compared to some other cells

it contains many organelles common to most unspecialized human cells

DNA/chromosomes

Information for making proteins

binary fission

-A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size -carried pout by most prokaryotes

adult stem cells

-Adult stem cells are undifferentiated cells, found throughout the body after development, that multiply by cell division to replenish dying cells and regenerate damaged tissues. -Also known as somatic stem cells, they can be found in juvenile as well as adult animals and humans, unlike embryonic stem cells

describe three structures that are present in plant cells but absent from animal cells

-Plant cells have a cell wall, which is a rigid protective layer that surrounds the entire cell. -Plant cells contain tiny organelles - inner structures - known as plastids, which animal cells lack. Plastids contain pigment or food that plants use to create energy. -Chloroplast, structure within the cells of plants and green algae that is the site of photosynthesis,

the basic principles of the cell theory

-all living things are composed of cells and cell products -new cells are formed only by the division of pre-existing cells -the cell contains inherited information (genes) that are used as instructions for growth, functioning, and development -the cell is the functioning unit of life; all chemical reactions of life take place within cells

what advantage does therapeutic cloning offer over conventional therapeutic use of embryonic stem cells?

-an advantage is that stem cell cloning produces genetically matched stem cells that can be divided into any cell type. -A major benefit of therapeutic cloning is that the cells removed are pluripotent. Pluripotent Cells can give rise to all cells in the body with the exception of the embryo, which means that pluripotent cells can potentially treat diseases in any body organ or tissue by replacing damaged and dysfunctional cells.

embryonic stem cell cloning

-combining a patient's body cell with an unfertilized egg cell from a donor. -The patient's skin cell is inserted into the outer membrane of the egg cell and chemically induced to begin developing into a blastocyst. -In the blastocyst, embryonic cells divide, producing a mass of stem cells.

paramecium

-common protozoan in freshwater and marine environments -feeds on bacteria, algae, and yeasts -ranging in size from 50 um to 300 um long

describe the location, role, and general composition of the bacterial cell wall

-lies outside the plasma membrane -it gives the cell shape, prevents rupture, and serves as an anchorage point for flagella -composed of peptidoayaln carbohydrate macromolecules- lipopolysaccharide and lipoprotein

what are the characteristics of a eukaryotic cell?

-membrane bound uncles and organelles -large -more structure and organization -multiple chromosomes -80S ribosomes

what are the characteristics of a prokaryotic cell?

-no membrane-bound nucleus or organelles -unicellular -small single cells -little cellular organization -cell wall -circular chromosome -70S (Svedberg units) in ribosomes

defining features of stem cells

-self renewal enables division whilst also maintaining a specialized state -potency enables differentiation of specialized cells

how are sex pili different from fimbraie and what is their significance?

-sex pili are different from fimbraie due to their use for exchanging genetic material in conjugation. -their significance is that they allow for the exchange of genes via the formation of "mating pairs".

unicellular eukaryotes

-single celled organisms that comprise the majority of the Protista kingdom -able to perform all life functions but in a rather diverse way

explain the role of stem cells in the development of specialized tissues in multicellular organisms

-stem cells are the first cell before any type of specialization; stem cell are able to give rise to any cells of the body -the cells first "specialize" in the same function which is essentially what tissues are and eventually those cells go through differentiation

embryonic stem cells

-stem cells derived from the undifferentiated inner mass cells of a human embryo. -Embryonic stem cells are pluripotent, meaning they are able to grow (i.e. differentiate) into all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm.

the cell wall and plasma membrane are found very close together. explain how they differ from one another

-the plasma membrane holds organelles together unlike the cell wall. -it is also thicker than the cell wall -Cell wall is metabolically inactive and non living. Cell membrane is metabolically active and living. -Cell wall is the outermost layer in plant cell and occurs as a protective covering surrounding the plasma membrane. Cell membrane is the outermost layer in animal cell and occurs as a semi permeable covering surrounding the protoplasm. -Cell wall is made up of cellulose in plant and of peptidoglycan in bacterium and made up of chitin in fungi.Plasma membrane is made up of lipids proteins and small amount of carbohydrates. -cell membrane can appear in animal cells, cell wall cannot

describe the function of flagella in bacteria and distinguish them from fimbriae

-used for locomotion -anchored in the plasma membrane -fimbraie are shorter, straighter, and thinner than flagella and fimbrae are used for attachment as opposed to locomotion

unit of length (international system)

1 m= 1000 millimetres 10^-3 m=1000 micrometres 10^-6 m=1000 nanometres 10^-9= 1000 picometres

cell size

2-100 um, with prokaryotic cells being approximately 10 times smaller than eukaryotic cells

Homeostasis

Cells and systems maintain a constant internal balance

Vesicles

Cellular package containing products such as protein

magnification equation

Image size/actual size

Ribosomes

Makes proteins

emergent properties

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.

explain how organelles increase the efficiency of the cell

Organelles increase the efficiency of cellular processes by concentrating the factors necessary to carry out specific biochemical reactions separate from the rest of the cell. Bacterial cells do not contain organelles or intracellular membrane-bound structures.

Pores/gated channels

Points of entry and exit for materials

Cytoplasm

Space for work to be done

cell theory

The cell is the basic unit of all living things.

cytoplasmic streaming

The motion of cytoplasm in a cell that results in a coordinated movement of the cell's contents.

Endoplasmic Reticulum

Transports and finishes proteins and other biological molecules

Svedberg unit

a measure of rate of sedimentation in centrifugation rather than size

why does a plant have both a rigid cell wall and membrane?

a plant has both a rigid cell wall and membrane because a plant doesn't have the means to defend itself on its own.

describe one potential advantage of using embryonic stem cells for tissue engineering technology

a potential advantage is that using these stem cells have been proven o restore diseased organs with function

umbilical cord blood is promoted as a rich source of multipoint stem cells for autologous transplants. can you see a problem with the use of a baby's cord to treat a disease in that child at a later date?

a problem is that because it requires the embryos, the cord blood could be at risk, ultimately putting the baby at risk.

nutrition

all cells require food to provide energy to power chemical reactions and nutrients to build cell component

response

all cells respond to their environment; receptors in the plasma membrane detect molecules in the environment and send signals to the internal machinery of the cell

explain what happens to the ratio of the surface area to volume with increasing size

as the size increases, the ratio of surface area to volume itself decreases

potency of stem cells

depends on their origin

distinguish between embryonic stem cells and adult stem cells with respect to their potency

embryonic stem cells retain potency through cell division meaning they have potential for therapeutic use in the medical world. however, adult stem cells only differentiate into a limited number of cell types.

Lysosomes

enzyme transport

Scenedesmus

freshwater green alga that forms colonies of 4, 8, sometimes 16 cells -its colonial existence and the outer spines give it protection from grazers

why is it necessary for plants to have chloroplasts?

it is important for plants to chloroplasts because it converts light energy to ATP to produce carbohydrates.

the central vacuole stores water. what would happen to the size of the central vacuole if a plan does not have enough water?

it would sink

cell membrane

maintains cell shape

Exceptions to the cell theory

muscle fibres, caulerpa, fungi

what features of a liver cell are associated with it being metabolically very active?

nucleus, mitochondrion, ER

explain the basis for correcting startgardt's disease using stem cell technology

once hESC is cultured in a lab, the cells are injected below the retina, replacing and repairing the patient's damaged vision/cells.

in your opinion, what is the one most important ethical issue associated with the use of embryonic stem cells in medicine?

one important ethical issue associated with the use of embryonic stem cells is the use of the embryo for reproductive cloning

explain why palisade cells are found in the upper region of the leaf

palisade cells are found in the upper region of the leaf because that way photosynthesis can be carried out completely

Examples of eukaryotic cells

plants, animals, fungi, protists, white blood cell, grass, yeast

how to find the surface area to volume ratio

put the surface area behind the colon and the volume in front of it and simplify it as much as possible: example: 24:8=3:1

plasma membrane

regulates what enters and leaves the cell

suggest why researches derived the RPE cells from embryos rather than reprogramming a patient's own cells

researches might have done this because it nourishes the retinae photoreceptor cells and protects it from light; patient's own eye won't do this

what advantage is there in reprogramming a patient's own cells and when would this be a preferable option?

since they are derived from a person's own cells, reprogramming allows for restoration in cells that are damaged. this is also an advantage because they are pluripotent. this is a preferable option when someone obtains an inherited disease.

actual object size equation

size of the image/magnification

Vacuole

storage structures for food, water, minerals, waste

Golgi apparatus

stores, modifies, and packages proteins

describe the function of the cell wall in plants

the cell wall supports the cell but also limits its volume; gives the cell strength and structure; filters molecules that pass in and out of the cell

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

explain why the formation of the cross wall is important in binary fission

the formation is important because it allows the cell walls to meet and form into two identical cells

cell differentiation

the process by which a cell becomes specialized for a specific structure or function.

what is the significance of this difference in their use in the treatment of disease?

the significance of embryonic stem cells is that embryonic can simulate to differentiate and multiply, and adult stem cells are found in many tissues but are hard to obtain.

describe the appearance of the vacuole in a well-watered plant. what effect would this have on the cell wall of the plant?

the stronger the vacuole, the healthier the plant is.

generation time

the time required for a bacterial cell to divide and/or double

Mitochondria

transforms energy into ATP,