Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?

The mucus is a physical trap that contains a variety of antimicrobial chemicals.
The mucus contains a variety of antimicrobial chemicals and molecules.
The mucus secreted by the mucous membrane physically traps microbes.
Both the mucus and the outer layer of cells are shed frequently.
The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

What causes an unsaturated fatty acid to have a different shape than a saturated fatty acid? o a. unsaturated fatty acids have more hydrogen atoms. o b. unsaturated fatty acids have double carbon bonds. o c. unsaturated fatty acids have more nitrogen atoms. o d. unsaturated fatty acids have single carbon bonds.

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction. this is an example of speciation.

In a hypothetical breed of dogs, coat color is controlled by two genes. there are six different coat colors in this breed: black, brown, cream, gray, silver, and tan. consider the following crosses. cross 1: black females from a lineage of all black dogs are crossed with brown males from a lineage of all brown dogs. f1 males and females are all black. when f1 are intercrossed, f2 males and females are black or brown. cross 2: black females from a lineage of all black dogs are crossed with tan males from a lineage where all males are tan and all females are cream. f1 males are black, f1 females are gray. when f1 are intercrossed, f2 males and females are black, brown, gray, or tan. cross 3: silver females from a lineage where all females are silver and all males are gray are crossed with brown males from a lineage of all brown dogs. f1 males and females are all gray. when f1 are intercrossed, f2 males are black, brown, gray, or tan, f2 females are cream, gray, silver, or tan. select the correct statements regarding the mode of inheritance of the coat color genes. a) both genes are x-linked. b) both genes are autosomal. c) one of the genes modifies the expression of the other gene. d) each gene has an additive effect on the intensity of coat color. e) each gene independently specifies three colors. f) one of the genes is autosomal, and the other is x-linked.