Lab 2 Flashcards
how do onions survive the winter
in the form of a bulb
how would you make a slide for onions
you would get a clear glass slide, use fine forceps peel the clear skin (epadermis) from the concave (inner) surface, place a drop of distilled water in the slide, put onion in water and place cover slide over
how would you inspect the prepared onion slide with a microscope
examine under the 4x and the 10x. scan slide and select a health, representative cell with nucleus, swith to 40x and identify structures
what structures should you be able to identify in a onion cell
cell wall
nucleus
nucleolus
central vacuole
cytoplasmic strands
cellular granuals
what does the cell wall do
it supports the cell
what does the plasma membrane
it is presses tightly to the cell wall (cant see it)
it regulates the passage of substances in and out of the cell
it is selectively permeable
what is the nuclear envelope
a double membrane that embounds the nucleous
what does the nucleus do
it controls the cell function by directing protein sysnthsis and storess genetic material
what is the nucleoli (singular-nucleolus)
it is a specialized region of the nucleus that manufactures ribosomal subunits
how much space does a central vacuole occupy
85-90%
what is the function of the central vacuole
it gives support to the plant cell when it is fully expanded and functions in storage of water as well as enzymes, ions, proteins, and toxins
where are cytomplasmic strands found
in an onion cell
why dont onion cells have a cytoplasm
due to the large sized vacuole the remainder of the cytoplasm is restricted to a narrow layerbetween vacuole and plasma membrane
what is cytoplasmic straming
tiny stands of cytoplasm. the tiny particles are cellular granules
what is the mitochondria
organells which are the site of cellular respiration and produces energy rich molecule ATP
what is ATP made of
made by the presents of oxygen and sugar
what can cytoplasmic streaming be made of
cytoplasm
mitochondria
leucoplast
what are plastids
a feature of plant cells have. there is 3 main types; chromoplasts, chloroplast, leucoplast
what are chloroplasts
they are the site of photosynthisis
what causes the color of the chloroplast
its due to the predomanence of green pigments called chlorophylls which are located on a set of membranes inside the chloroplast called thylokoid membranes. these pigments capture the light energy used in photosynthesis
how do you prepare a slide for a green pepper
use a razor blade and make a very thin cross sections of a peice of green pepper. select the thinnest one then add a drop of distilled water then add a cover slip
how would you look at a green pepper under a slide
under the 4x objective lends find the area of green cells below the skin.
scan slide and select the thinest portion of you section.
examine under the 10x and 40x
what are the features you should label for the green peper
chloroplast
cell wall
central vacuole
nucleus
nucleolus
what pigments do chromoplasts contain. and what colour are they
they contain pigments called carotenoids and are typically yellow, orange red or dark purple
where are chromoplast usually found
they are commonly found in flowers and ripe fruits, where their colour attracts animal for pollonation (in flowers) or seed dispersal (in fruit)
they are also responsible for colour of fall leaves
how do you prepare a slide for red peppers
use fine forceps, carefully peel the skin from the outer surface of a piece of red pepper (capsicum) fruit
mount this tissue i a drop of distilled water
apply coverslip
how do you examine a red pepper slide
examine the cells along the edges of your peel under the 40x objective
what are the structures to look for on a red pepper
cell wall
plasmodesmata
chromoplast
central vacuole
nucleus
what is plasmodesmata
plants communicate with each other via slender cytoplasmic connections called pasmodesmata
many run through each perforation (holes between the “bubbles” of the cell wall and connect adjacent cells
what does the term leucoplast refer to
a group of non pigmented plastids that function in storage of starch, proteins, or fats
why are leucoplast hard to distinguish with light microscopy
due to there small size and lack of pigment
what do lucleoplast look like
many egg shaped clear dots
what are leucoplasts like in bananas
they are in the form or starch grains. these starch grains are so big that they have out grown the leucoplast abd are free in the cytoplasm (lucleoplast have burst and no longer visible)
how do you make a slide for a banana
use the blunt end of a tooth pick and touch the end of the banana
place a drop of distilled water on the silde and then rub in the banana
how do you examine banana cells under the microscope
examine cells under 40x objective lends. the cells are colorless. youll need to close the iris diaphram to examine.
carefully examine a single starch grain and note its layered aperance
what are they layers on a banana starch
the layers are called saturations. in many species of plants each striation corresponds to a day of starch deposition
what should you label in a banana cell
cell wall
starch grains
cytoplasm
saturations
what are anthocyanins
they are a class of blue, purple and red pigments that occur in the central vacuoles of some plant cells
where are anthocyanins found
they are water soluble. they are dissolved in water and stored in the central vacuoles of some plant cells
where are anthocyanin commonly found
they occur in flowers but may be present in some fruits (e.g. grapes, blueberries), leave and roots
how do you prepare/look at a slide for a coral bells/alum root
using fine forceps peel a small piece (appx 5mm) of epidermis
mount this tissue in a drop of distilled water, apply cover slip, examine cells along the edge of your peel under the 4x and 10x objectives
what structures should you see in coral bells/alum root
cell wall
plasmodesmata
central vacuole
nucleus (if visible)
what should you be able to near a guard cell
chloroplast
cell wall
central vacuole
stoma
what regulates the opening and closing of a stomata
the specialized guard cells. through which gas exchange occurs
what is the process of photosysnthesis
the process which uses light energy to synthesize sugars from carbon di oxide and water while releasing oxygen and the by product
what structures should you be able to see on your cheek slide
nucleus
cytoplasm
plasma membrane
what sells are usually bigger plant or animal
plant cells
why do you need to stain a cheek cell
because like most animal cells it is colourless. stain increases contrast so you can see cell and components more clearly
what stains DNA dark blue
methyl blue
what is an amoeba
a unicellular animal like protist
what is amoeba bounded by
a plasma membrane
what is pseudopodia. where can they be found
(false foot) cellular extentions that form as the granular cytoplasm flows forward, enabling the organism to crawl along the substrate. found in amoeba
what is found in the cytoplasm of the amoeba. what do they do
many smaller granules and crystals. they have an unknown function
what are the cytoskelletion components in the amoeba? and what are they responsible for
they are responsible for pseudopod formation and they are microfilaments
what are microfillaments
they are composed of actin subunits, involved in cytoplasmic streaming and division of cytoplasm (wouldnt b visible on a slide)
what do amoeba uses it pseudopodia for
to encircle and trap small animals and other food particles, a process called phagocytosis
what does phagocytosis mean
cell eating
what happens to the food that has been acquired from phagocytosis
-food is packages into food vacuoles
-stored temporarily in food vacuoles prior to digestion
-membrane bound lysosomes fuse with food vacuole and supply hydrolytic enzymes which digest food within vacuole
in amoeba how would you distinguish the nucleus form contractual vacuole
-nucleus is grey, granular, and bean shaped
-contractual vacuole is colorless and perfectly circular
what does the contractile vacuole function as
functions in osmoregulation
what is osmoregulation
maintenance of a constant internal solute concentration by and organism
what does the contractile vacuole vanish sometimes
because it is contracting to empty its contents (excess water)
what structures should you be able to label in the amoeba
plasma mem
psedopodium
nucleus
contractal vacuole
food vacuole (is seen)
cytoplasm
while amoeba uses microfilament to create its pseudopodia what are other ways animal cells move
cilia or flagella
what are cilia or flagella made from
they are made of cytoskeletal components called microtubules
what do specialized motor proteins do for the flagella and cilia
they work agents the microtubules to create a bend in the cilium or flagellum. this bending causes the characteristic oar-like movement of cilia and the whip like motion of the flagella
how can you see the cilia of a paromecium
close the iris diaphragm and you’ll see the beating of cilia, tiny appendages that cover surface of the cell
what structures should you be able to label on a paramecium
nucleus
cilia
oral grove
how is flagella different from cilia
they have the same internal sturcture but flagella are longer and usally only come in groups of 1 or 2 per cell
