the alveoli are made of thin squamous (type I) alveolar cells which allows for the quick diffusion carbon dioxide and oxygen.
Diffusion of gases takes place between the alveolar cavity and the blood in the capillaries. Oxygen being more concentrated in the alveoli diffuses across the epithelium of the alveoli and the endothelium of the capillaries into the blood. The epithelial walls of the alveoli are moist and thin thus enhancing the diffusion.
The tertiary structure of a protein is the _____. a. Organization of a polypeptide chain into an α-helix or β-pleated sheet
b. Order in which amino acids are joined in a polypeptide chain.
c. Unique three-dimensional shape of the fully folded polypeptide
d. Overall protein structure resulting from the aggregation of two or more polypeptide subunits
C. Unique three-dimensional shape of the fully folded polypeptide
The tertiary structure of a protein is the unique three-dimensional shape of the fully folded polypeptide
A protein is a functional biological molecule that is made up of one or more polypeptides that are folded/coiled into a specific structure.
-As the secondary structure becomes established due to the primary structure, a polypeptide folds and refolds upon itself to assume a complex three-dimensional shape called the protein tertiary structure. Tertiary structure results from the interactions between the side chains (R groups) of the various amino acids.
6. Which statement has been proven true of children of adolescent parents? (Points : 1) They have lower IQs. They are less connected to their parents. They have lower academic performance. They choose not to have children of their own.
Which of the following types of glial cells are the most abundant and versatile, and aid in making exchanges between capillaries and neurons? a. microglia b. ependymal cells c. oligodendrocytes d. astrocytes
The correct option is d. Astrocytes are the most abundant and versatile glial cells, and aid in making exchanges between capillaries and neurons.
Glial cells have the function of protecting neurons and keeping them together, that is, they act as support cells. Among them we find:
Astrocytes are the most abundant glial cells, star-shaped and located in the central nervous system (in the brain and spinal cord). Its function is to maintain an appropriate chemical environment for neurons to exchange information, helping the exchange between neurons and capillaries. In addition, they wrap the capillaries forming part of the blood-brain barrier.
The other options are also glial cells but with different functions:
Microglia: They are extremely small glial cells of the central nervous system, their function is to elicit neuronal wastes and defend or protect the brain from external microorganisms .
Ependymal cells: These are ciliated glial cells of the central nervous system that form the epidendum and cover the ventricles of the brain and the central duct of the spinal cord.
Oligodendrocytes: This type of glial cell involves some neuronal axons, provides support for neuron prolongations and produces myelin.
The pollen lands on which part of the flower?
In flowers, the feminine reproduction organ is only one structure with three parts: stigma, style, and ovary.
Stigma: the place where pollen land.
Style: it has liquid to retain the pollen spore, between stigma and ovary.
Ovule: its the feminine gamete of plants. In the contact of pollen, it produces a new plant.
Integument: a thin membrane covers the ovary and the style. It has an opening at the stigma for the pollen.
4. Why do leaves change colors in the fall?
The pigment that causes leaves to be green is chlorophyll. Chlorophyll is important for plants to make food using sunlight. ... As chlorophyll goes away, other pigments start to show their colors. This is why leaves turn yellow or red in fall.
In autumn when it starts to get cold, some plants stop making chlorophyll. Instead, those plants break down chlorophyll into smaller molecules. As chlorophyll goes away, other pigments start to show their colors. This is why leaves turn yellow or red in fall.
to give nutrients to the grass/the tree itself
once the Winter goes by, the leaves decay and give off nutrients for the soil to regain the nutrients it needs to keep the plants safe and healthy
i hope this help ;)
in the previous section, you learned that the allele for brown eyes (B) is dominant, and blue (b) and green eyes (g) are recessive, well green eyes are dominant over Blueeyes. What I color would someone with the following genotypes exhibit? (a) BB, (b) Bb, (c) gb, (d) Bg, (e) bb.
Answer: (a) BB will have brown eyes
(b) Bb will have brown eyes
(c) gb will have green eyes
(d) Bg will have brown eyes
(e) bb will have blue eyes
Explanation: Allele for brown eyes (B) is dominant, therefore it will manifest outwardly whether is in a homozygous or a heterozygous condition. In this case, BB,Bb and Bg will manifest as brown eyes. Allele for blue eyes (b) and that for green eyes (g) are recessive but (g) is dominant over (b), therefore gb will manifest outwardly as green eyes.
Because (b) is recessive, it must occur in a homozygous state in order to manifest outwardly. This means that (bb) will manifest outwardly as blue eyes.
What is the most common debilitating disease of childhood among those of european descent?
Cell walls are made of cellulose in ____________ cells. A) animal B) bacteria C) fungal D) plant
Plant cell walls are made of cellulose (D)
Name the hormone secreted by the hypothalamus that stimulates the release of follicle stimulating hormone and luteinizing hormone by the anterior pituitary gland.