The rib cage is known for enclosing and protecting the thoracic cavity. In the thoracic cavity, the heart and lungs are present. Hence, the rib cage protects the heart.
Answer;
-Cervical enlargement
Explanation;
-The spinal cord has an obvious enlargement in the cervical region, called the cervical enlargement, where the cell bodies controlling the upper limbs arise.
-It is a spindle-shaped swelling of the spinal cord that extends from the third cervical to the second thoracic vertebra, with maximum thickness opposite the fifth or sixth cervical vertebra, consequential to the innervation of the upper limb.
Answer:
B, C, Dand E are all correct
Explanation:
Why B is correct- The cell membrane, also known as the plasma membrane, is a double layer of lipids and proteins that surrounds a cell and separates the cytoplasm (the contents of the cell) from its surrounding environment. It is selectively permeable, which means that it only lets certain molecules enter and exit.
Plants, animals, and bacteria have a cell membrane. Why d is correcect
Why C is correct- The cell membrane is not a solid structure. It is made of millions of smaller molecules that create a flexible and porous container. Proteins and phospholipids make up most of the membrane structure.
Why E is correct- The plasma membrane is primarily composed of phospholipids arranged in a bilayer, with the hydrophobic tails on the interior of the membrane, and the hydrophilic heads pointing outwards
Why A Is Not correct- It is very fragile and its role is to hold the cell together and to help control what substances can get in and out. It is partially permeable, allowing only some substances to pass through it. The membrane has a complex structure consisting of a phospholipid bi-layer and different types of proteins.
Answer:
Because the sexual reproduction joins two cells that each have half the total chromosome number :)