My Lab#2 Hmwk
During ________, the shortest phase of mitosis, chromosomes are pulled toward the poles of the cell.
anaphase
This tissue type is a covering and lining tissue. It includes glands.
epithelial
This accessory organ of the skin is composed primarily of dead, keratinized cells.
hair
Which layer is highlighted?
hypodermis
Which structure is highlighted?
reticular layer of dermis
These glands are found all over the skin except in the palms of the hands and soles of the feet. They produce an oily substance that lubricates skin and hair.
sebaceous glands
What is secreted by the highlighted structure?
sebum
Only one human cell has a flagellum. This specialization allows the cell to propel itself forward. It is a ________.
sperm cell
From deep to superficial, the layers of the epidermis of thin skin are ________.
stratum basale, stratum spinosum, stratum granulosum, stratum corneum
During which stage of mitosis does cytokinesis end?
telophase
Identify the stage of mitosis.
telophase
During which phase of mitosis do sister chromatids line up at the center of the cell?
Metaphase Spindle microtubules from both poles of the cell attach to the sister chromatids and pull them in both directions. During metaphase, the sister chromatids are forced to the center of the cell.
During which phase of mitosis do nuclear envelopes and the nucleoli reappear?
Telophase Telophase begins when the chromosomes stop moving. Nuclear envelopes form, and nucleoli reappear. Ultimately, the cell divides in two by a process known as cytokinesis.
A dialysis sac that is permeable to glucose and water is filled with water and placed in a beaker containing 20% glucose solution. Will there be a net transport of glucose across the dialysis sac? If so, in which direction will the glucose move, into the sac or out of the sac?
Yes, glucose will move into the sac.
Which structures would you expect to find in the highlighted layer?
blood vessels, free nerve ending, and receptor cells
What is produced by the highlighted structures?
sweat
These molecules diffuse through the lipid portion of the plasma membrane.
CO2 and O2
What is the name of the process by which the cytoplasm divides in two?
Cytokinesis
The nucleus of the cell contains its genes, which are sections of ________.
DNA
What is true about the blood supply to the skin?
Epidermis is avascular and dermis is richly vascularized.
During which phase of the cell cycle does DNA duplication, or replication, take place?
Interphase DNA replicates during interphase. This process provides each new daughter cell with a full complement of genetic material.
Which statement about vesicular transport is true?
Pinocytosis is used to take liquids into a cell.
During which phase of mitosis do the nuclear envelope and nucleoli disappear?
Prophase Prophase is the first phase of mitosis. During this phase, the sister chromatids condense, the nuclear envelope and nucleoli disappear, and the spindle apparatus forms.
What is not true of epithelial cells?
They are richly vascularized. These are True: They are bound together to form sheets. They have a free surface. They regenerate readily.
The force that causes water and solutes to cross cell membranes by filtration is ________.
a hydrostatic pressure gradient
Identify the stage of mitosis.
anaphase
Cutaneous glands, hair, and nails ________.
are accessory structures of the skin, are derived from stratum basale in the epidermis, and reside in the dermis
Squamous epithelial cells ________.
are thin and flat, like fish scales
Which structure is highlighted?
arrector pili muscle
This organelle is particularly important during cell division. It directs the formation of the mitotic spindle.
centriole
When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called sister __________.
chromatids Each new daughter cell receives one of the sister chromatids. After the chromatids separate, each is considered a new chromosome. At the end of cell division, each new cell contains 23 pairs of chromosomes.
The outermost surface of the hair is called the __.
cuticle
The nucleus, plasma membrane and ________ are the three major regions of cells that can readily be seen with a light microscope.
cytoplasm
This connective tissue is packed with parallel collagen fibers, attaches muscles to bone, and can withstand great stress when pulled in one direction.
dense regular
Pressure receptors, called Pacinian corpuscles, are located in this layer of the integument.
dermal reticular layer
This region of the skin contains abundant elastic and collagen fibers.
dermis
Two important passive processes for membrane transport are ________.
diffusion and filtration
Common functions of cells include ________.
digesting nutrients and disposing of wastes
Which structure is highlighted?
duct of sudoriferous gland
Bone and cartilage are connective tissues that have ________.
ground substance that is firm or hard
Which structure is highlighted?
hair follicle
Which structure is highlighted?
hair root
This organelle digest other worn-out organelles and foreign substances that have entered the cell.
lysosome
Identify the stage of mitosis.
metaphase
Simple epithelia have ________.
one type of epithelial cell, arranged in a single layer
This layer of the dermis is responsible for fingerprints.
papillary layer
Membrane transport may be passive or active. Select the active process from the list below.
phagocytosis passive tranports are diffusion, filtration, osmosis
Identify the stage of mitosis.
prophase
This layer of the epidermis contains translucent cells filled with keratin fibrils. It is found only in thick skin.
stratum lucidum
Which layer is highlighted?
stratum spinosum
During which phase of mitosis do the sister chromatids move apart?
Anaphase During anaphase, the centromeres split and the spindle microtubules pull the sister chromatids to opposite poles of the cell. The single chromatids are now considered chromosomes.