1).describe how oxygen enters the haemolymph of an insect

Question

2)a.draw and label the gill from a bony fish
b).state the function of each parts
c). give three adaptations of the gill filaments to gaseous exchange
d). give three reasons why a fish dies when removed in water
3). how is the trachea adapted to its functions
4). describe the mechanism of gaseous exchange in
a). a bonny
b). human being
c). insect
5). describe the changes that occur to the ribcage and diaphragm during
a). inhalation
b). exhalation

Answer 1

1) In insects, oxygen enters the haemolymph through tiny tubes called tracheae. These tracheae are connected to tiny openings called spiracles that are located on the insect's body surface. Oxygen diffuses through the spiracles and travels through the tracheae to reach the cells of the insect's body.

2) a) A gill in a bony fish consists of thin, fleshy membranes called gill filaments attached to gill arches.
b) The function of each part of the gill in a bony fish is as follows:
- Gill filaments: These are the main sites of gaseous exchange. They are thin and have a large surface area, allowing for efficient oxygen absorption and carbon dioxide release.
- Gill arches: These provide support for the gill filaments and contain blood vessels that carry deoxygenated blood away from the gills.

c) Three adaptations of the gill filaments for gaseous exchange in fish are:
- Lamellae: These are small, finger-like projections on the gill filaments that increase the surface area available for gas exchange.
- Countercurrent exchange system: Blood flows in the opposite direction to water flow, maximizing the oxygen diffusion gradient across the gill surface.
- Thin epithelial layer: The gill filaments have a thin layer of cells, facilitating the diffusion of gases between the water and the bloodstream.

d) Three reasons why a fish dies when removed from water are:
- Lack of oxygen: Fish obtain oxygen from water through their gills. When removed from water, they are unable to extract enough oxygen from the air to sustain their metabolism.
- Dehydration: Fish have a thin mucous layer on their skin that helps prevent water loss. When out of water, this protective layer is compromised, leading to dehydration.
- Heat stress: Water acts as a temperature buffer, so when fish are removed from water, they are exposed to rapid temperature changes that can be harmful or even fatal.

3) The trachea in insects is adapted to its functions by being a highly branched network of tubes that deliver oxygen directly to individual cells in the insect's body. It is supported by chitin rings to prevent the collapsibility of the tubes. The tracheal tubes extend throughout the insect's body, allowing for the efficient exchange of gases and the removal of waste products.

4) a) In bony fish, gaseous exchange occurs as water containing dissolved oxygen flows over the thin, vascularized gill filaments. Oxygen diffuses across the gill membranes into the bloodstream while carbon dioxide diffuses out of the bloodstream into the water, to be expelled as waste. This process is known as counter-current exchange, where water and blood flow in opposite directions to maintain a steep oxygen concentration gradient.

b) In humans, gaseous exchange occurs in the lungs. Oxygen is inhaled through the nose or mouth, passes down the trachea, and into the bronchi. The bronchi branch into smaller tubes called bronchioles, which eventually lead to tiny air sacs called alveoli. Oxygen diffuses from the alveoli into the surrounding capillaries, while carbon dioxide diffuses from the capillaries into the alveoli to be exhaled.

c) In insects, gaseous exchange occurs through their tracheal system. Minute tubes called tracheae extend throughout the insect's body, carrying air directly to the cells. Oxygen diffuses from the tracheae into the cells, and carbon dioxide diffuses out from the cells into the tracheae. This exchange occurs by simple diffusion driven by concentration gradients.

5) a) During inhalation, the ribcage expands as the intercostal muscles contract. This movement causes the ribs to move upwards and outwards, increasing the volume of the thoracic cavity. The diaphragm contracts and moves downwards, further increasing the thoracic volume. These changes in the ribcage and diaphragm create a decrease in air pressure in the lungs, allowing air to flow in and fill the expanded lungs.

b) During exhalation, the ribcage returns to its resting position as the intercostal muscles relax. This causes the ribs to move inwards and downwards, decreasing the volume of the thoracic cavity. The diaphragm relaxes and moves upwards, reducing the thoracic volume even more. These changes increase the air pressure in the lungs, causing air to be expelled from the lungs during exhalation.

Answer 2

solve x+8 is greater than 10

Answer 3

To solve the inequality x + 8 > 10, we can isolate the variable x on one side of the inequality sign.

Starting with x + 8 > 10, we can subtract 8 from both sides of the inequality:

x + 8 - 8 > 10 - 8

This simplifies to:
x > 2

So, the solution to the inequality is x > 2.

Answer 4

x-1/3 is less than or equal to 1/2

Answer 5

To solve the inequality x - 1/3 ≤ 1/2, we can isolate the variable x on one side of the inequality.

Starting with x - 1/3 ≤ 1/2, we can add 1/3 to both sides of the inequality:

x - 1/3 + 1/3 ≤ 1/2 + 1/3

This simplifies to:
x ≤ 5/6

So, the solution to the inequality is x ≤ 5/6.