Correct Answer: A. Transmission of hereditary traits

Correct Answer: A. blood plasma and the red blood cells are isotonic

Correct Answer: D) None of the above

Explanation

Crocodiles are not fishes, amphibians, mammals, or birds. Therefore, the correct answer is Option D: None of the above. Crocodiles are reptiles, which means they are cold-blooded animals that lay eggs and have scales or scutes on their skin. They are members of the family Crocodylidae and are closely related to alligators and caimans. Crocodiles are aquatic predators that live in rivers, lakes, and wetlands in tropical and subtropical regions around the world. They have a powerful bite and can easily overpower prey such as fish, birds, and mammals. They are also apex predators, meaning they have no natural predators in their ecosystem. In summary, crocodiles are reptiles and not fishes, amphibians, mammals, or birds. They are aquatic predators that live in tropical and subtropical regions around the world and have a powerful bite that allows them to easily overpower their prey.

Explanation

(i) Sewage : Waste matter/ feaces, urine, waste water from animals/industrial/domestic sources; that is dissolved/ suspended in water.

(ii) Effects of releasing untreated sewage into a stagnant water body;

• Spread of water-borne diseases/correctly named diseases/microbes/pathogens
• May be toxic/poisonous to aquatic life/organisms
• Makes water unfit for consumption/use
• Increased decomposition
• Increased concentration of nutrients
• Rapid growth of algae/aquatic plants/algal bloom/eutrophication
• Depletion of oxygen
• Suffocation/death of aquatic animals
• Generates offensive odour/air pollution
• Nutrient/nitrate/phosphate enrichment/accumulation in a water body; as a result of breakdown by bacteria.

(b) Surface terracing as a soil conservation method :

A method of controlling erosion on a gentle/steep slope of hill; flat horizontal areas are constructed on which crops are cultivated; following the contour; steps/walls are built along the contous; plughing is also done along the contours; reduces the speed of water running down the slopes.

(c)Adaptation: Is the possession of the characteristic/trait/behaviour/structure/feature; that evolved over a period of time; enable an organism to survive and reproduce; in response to changes in the environment/habitat.

(d) Adaptation of;

(i) Hydrophytes

1. Some hydrophytes lack/have reduced roots/root hairs/root caps
2. do not need firm anchorage in water/wetland
3. presence of large air space parenchyma in roots/leaves; provide support for buoyancy
4. Presence of hairs on the leaves; to prevent blockage of the stomata
5. stomatal pores; occur only at the upper epidermis of the leaves to aid transpiration/loss of water
6. numerous adventitious roots and root hairs; aid the absorption of water/mineral salts
7. small size of the plant; for buoyancy/floating in water
8. waxy upper surface of the leaf; to prevent clogging of the leaf by water
9. long petiole/leaf stalk to support/ expose the broad lamina for photosynthesis
10. long flower stalk/pedicel; to expose flower for pollination/ pollinating agents
11. presence of breathing roots/pneumatophores; for breathing/gaseous exchange.

Xerophytes

1. possession of thick succulent leaves/stem; for storing water
2. reduction of leaves to spines; to reduce water loss/rate of transpiration
3. thick waxy cuticle on epidermis; to reduce water-loss/transpiration
4. possession of long tap root system; tp obtain water from great depth of soil
5. presence of sunken stomata; to reduce water loss
6. reduced number of stomata; to prevent excessive water loss
7. possession of multiple epidermal layers; for water conservation/to reduce water loss.

Correct Answer: D. calcium, magnesium and potassium

Explanation

(a)(i) Excretion: The elimination of waste products; of metabolism; from the body of an organism.

(ii) Excretory organs in Humans with their waste products.

Excretory Organs in humans Waste Products

Kidney - Nitrogenous wastes/urea/water/salts/urine

Skin - Urea/SaltsNVater/Sweat

Liver - Bile/excess cholesterol

Lungs - CO2/water vapour.

(b) Functioning of kidney as excretory:Blood from the renal artery enters the bowman's capsule; through the afferent arteriole; ultra filtration occurs in the Bowman's capsule; high pressure in the glomerulus causes the filtration of small molecules/amino acids/ glucose/ minerals salts/ water/ urea; out of the blood plasma into the cavity of the capsule; the filtrate/glomerular filtrate passes through the nephron; where selective reabsorption of useful metabolites/glucose/amino acids take place; in the descending/first proximal convoluted/coiled tubule; the reabsorption of salts and water is regulated in the loop of Henle; and the ascending/second/distal convoluted tubule/large waste molecules like creatine secreted at loop of Henle; depending on blood concentration; the filtrate continues into the main collecting duct/tube; where further reabsorption of water and salt takes place; the remaining fluid in the duct becomes urine.

(c) Excretory organs in;

(i) Insects → Malpighian tubules

(ii) Earthworm →Nephridia/Nephridium

Correct Answer: D) Decomposer

Explanation

In a community, there are different types of organisms that play different roles. Bacteria and fungi are two types of organisms that are commonly found in communities. These organisms are known for their role in breaking down dead organic matter, such as dead plants and animals. This process is important because it helps to recycle nutrients back into the ecosystem. The question is asking us to identify the term used to describe bacteria and fungi in a community. The options given are producers, consumers, scavengers, tertiary consumers, and decomposers. Of these options, the correct answer is decomposers. Decomposers are organisms that break down dead organic matter and recycle nutrients back into the ecosystem. They are essential for maintaining the health of an ecosystem because they help to prevent the buildup of dead organic matter. Without decomposers, nutrients would become trapped in dead organic matter, making them unavailable to other organisms in the ecosystem. It's important to note that while bacteria and fungi are both decomposers, they are not the only decomposers in an ecosystem. Other organisms, such as worms and insects, also play a role in breaking down dead organic matter. In conclusion, in a community, bacteria and fungi are referred to as decomposers because they break down dead organic matter and recycle nutrients back into the ecosystem.

Correct Answer: C. Lizard

Correct Answer: D. saprophytic

Correct Answer: A. attract pollination agents