Answer:
Proportion of the F2 male with red eyes and forked bristle will be 1/4
Explanation:
forked bristles are caused by an allele (Xf) that is X linked and recessive to an allele for normal bristles (X+).
Brown eyes are caused by an allele (b) that is autosomal and recessive to an allele for red eyes (b+)
A female fly that is homozygous for normal bristles and red eyes mates with a male fly that has forked bristles and brown eyes
X+X+b+b+ x Xfbb
the F1 gives 1/2X+Xf 1/2b+b
1/2X+Y 1/2b+b
intercross of F1
Proportion of the F2 male with red eyes and forked bristle will be
forked bristle= Xfy = 1/2 and for red eyes 2/4= 1/2 = 1/2x1/2 =1/4
Answer:
B. increasing osmotic pressure in the glomerular capillaries that reduces the amount of filtration
Explanation:
Answer:
The receptor senses changes in the environment and responds by sending information (input) to the control center along the ascending pathway. The control center analyzes the input, determines the appropriate response, and activates the effector by sending information along the descending pathway. When the response causes the initial stimulus to decline, the homeostatic mechanism is referred to as a negative feedback mechanism. When the response enhances the initial stimulus, the mechanism is called a positive feedback mechanism. Negative feedback, mechanisms are much more common in the body.
Explanation:
Homeostasis is the adaptation of living organisms or systems to new conditions in the environment by auto-regulation. Through this mechanism, an equilibrium state can be maintained in spite of any changes. This adjustment in the physiological system is called <em>homeostatic regulation</em> and it is composed of three parts: the receptor, the control center, and the effector.
The receptors receive information from the environment about something changing and transmit that information to the central nervous system (control center). This pathway is defined as the ascending pathway. Information is processed in the control center which handles many sensory signals, evaluates them, compares them and uses them for decision making. After that, an efferent neuron is stimulated to carry information from the central nervous system to the effector cells of the target organ. The effector may be muscle or glandular tissue. This pathway is defined as the descending pathway. Finally, the target organ responds.
There is negative feedback when the response declines the initial stimulus, which is the <u>most common mechanism</u> in the body. There is positive feedback when the response enhances the initial stimulus, which might be very nocive to the organism.
Answer:
Characteristics of epithelium tissue
1.Polarity- Epithelium is arranged so there is one free surface (apical surface) and one attached surface (basal surface)
2.Cellular nature– Cells in epithelium fit closely together side by side and sometimes atop each other to form sheets of cells. These sheets are held together by specialized junctions.
3.Supported by connective tissue– Attachment to a layer of connective tissue at the basal surface forms a layer called the basement membrane, an adhesive layer formed by secretions from the epithelial cells and the connective tissue cells.
4.Avascular– Epithelium typically lacks its own blood supply.
5.Regeneration– Epithelium cells can regenerate if proper nourished.
6.Absence of nerves (except for a few axons in the deeper layers)
Classification scheme of epithelial tissue:
Typically epithelial tissue is classified on the basis of arrangement and shape of cells. For naming the tissue types, the arrangement of the cells is stated first, then the shape, and is followed by “epithelium” to complete the naming. For example; Simple Squamous Epithelium.
Explanation:
