Explanation:
The ribs are a set of twelve bones which form the protective 'cage' of the thorax. They articulate with the vertebral column posteriorly, and terminate anteriorly as cartilage (known as costal cartilage). As part of the bony thorax, the ribs protect the internal thoracic organs.
A. The DNA is duplicated.
There are three steps in Interphase: G1, Synthesis, and G2. G1 is growth, Synthesis is duplication, and G2 is more growth.
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Answer:
a. Species A survived because of its widespread range including some areas that were not as affected by mass extinction.
Explanation:
The species distribution might confer extinction resistance during massive extinction events. One of the most important reasons for a species -or any other taxonomic group- to survive massive extinction is its wide distribution area.
The broad geographical range of a group -as Species A in the example- enhances the survival chances during mass extinctions. When the event occurs, it severely affects most individuals of a certain area. If the species is restricted to that area, then the species will probably disappear, no matter the number of individuals living there.
But if the species is widely distributed, there are more survival chances. The extinction event will only affect a few regions, but not all of them, meaning that some of the individuals of the species will be able to survive.
Probably as only a few individuals of species A got to survive, they must have suffered the effects of genetic drift after the disaster, causing a reduction in genetic variability.
The correct answer is option (A) abundance of collagen fibers.
Bones are a type of supportive connective tissue forming an integral part of the skeleton. Bone tissue is made up of the different types of bone cells embedded in a matrix.
Bone matrix is mainly composed of the collagen fibres, also known as the ossein. They are fibrous protein units linked together rendering elasticity and improving fracture resistance. Collagen fibres are long, very flexible with a high tensile strength and resist stretching. They impart the characteristic resilience and strength, allowing it to withstand strong tension in case of bones, tendons, ligaments.
1) The correct answer is: 128 combinations.
The genetic combinations that are possible through independent assortment can be calculated as 2^n; where n is the number of different chromosomes.
So, using this formula for 7 chromosomes:
2^7 = 128 different combinations.
2) For a zygote produced by two barley parents, the number of possible genetic combinations can be calculated as: 2^n * 2^n
So, for 7 chromosomes: 2^7 * 2^7=16384
