The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
Answer:
Cytoskeleton
Explanation:
It provide mechanical support that enables cells to carry out function like division and movement
Answer:
theyed eventually become extinct because they are unable to reproduce
Physical activity causes an increase in your heart rate. Your body have to change the way it behaves so you don’t get ill or sick or pass out during physical exertion
Mitosis
Involves one cell division?
Results in two daughter cells
Results in diploid? daughter cells? (chromosome? number remains the same as parent cell)
Daughter cells are genetically identical
Occurs in all organisms except viruses
Creates all body cells (somatic?) apart from the germ cells? (eggs and sperm)
Prophase is much shorter
No recombination/crossing over occurs in prophase.
In metaphase individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase the sister chromatids are separated to opposite poles.
Meiosis
Involves two successive cell divisions
Results in four daughter cells
Results in haploid? daughter cells (chromosome number is halved from the parent cell)
Daughter cells are genetically different
Occurs only in animals, plants and fungi
Creates germ cells (eggs and sperm) only
Prophase I takes much longer
Involves recombination/crossing over of chromosomes in prophase I
In metaphase I pairs of chromosomes line up along the equator.
During anaphase I the sister chromatids move together to the same pole.
During anaphase II the sister chromatids are separated to opposite poles.
Similarities
Mitosis
Diploid parent cell
Consists of interphase, prophase, metaphase, anaphase and telophase
In metaphase individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase the sister chromatids are separated to opposite poles.
Ends with cytokinesis.
Meiosis
Diploid parent cell
Consists of interphase, prophase, metaphase, anaphase and telophase (but twice!)
In metaphase II individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase II the sister chromatids are separated to opposite poles.
Ends with cytokinesis.
