Correct Answer: C) flame cell

Explanation

The question is asking which structure functions as an excretory system in flatworms. The options are Contractile Vacuole, Nephridium, Flame Cell, Malpighian Tubule, and Kidney. Of these options, the correct answer is Flame Cell. Flame cells are found in flatworms and function as an excretory system. They are responsible for removing waste products from the body. Contractile vacuoles are found in unicellular organisms such as Paramecium, and they function to remove excess water from the cell. Nephridia are found in annelids and function as excretory systems. Malpighian tubules are found in insects and arthropods, and they also function as excretory systems. Kidneys are found in vertebrates and function as excretory systems. So, in summary, the structure that functions as an excretory system in flatworms is the flame cell. To learn more about this, please read the relevant sections of the recommended textbooks.

Correct Answer: D. grasping prey

Correct Answer: B. O2

Correct Answer: A. hold onto its prey

Explanation

(a)(i)Population: This is a group of individuals; of the same species; inhabiting a particular area/habitat; at a particular point in time.

(ii)Competition: - This is the interaction between members of the same population/ species/intra - specific/two or more populations/species/inter - specific; occupying the same trophic level; to obtain mutually needed resources; that are short in supply in their environment.

(iii)Succession: - This is the step by step/orderly; and gradual replacement of communities; arising from a change in the environment/environmental factors; which leads to a climax/stable community.

(b) (i) Sources of noise pollution: -

• Electronic sound system
• Sirens
• Generators
• Airplanes
• Factory machines
• Industrial machines
• Canons shots/guns firing
• Artillery firing
• Quarry activity/construction site
• Motor vehicles.

(ii) Prevention:

• Legislation
• Education/public enlightenment
• Siting factories, industries, military site away from residential areas
• Use of sound proof/silent generators.

(c)(i) Effects of smoke on humans: -

• Causes breathing difficulties.
• Causes injury to the lining of respiratory tracts/ lungs.
• Reduces visibility; reduces photosynthesis leading to lower crop yield.
• Causes discomfort to the eyes.
• Contains carbon monoxide which is injurious to man.

(ii) Effects of sewage on human:

1. Untreated sewage discharged into water bodies makes water unfit for drinking/swimming
2. may cause spread of water borne diseases/correctly named borne disease.
3. its toxic to aquatic organisms thereby depleting food source for man.
4. makes water unsafe for domestic use.
5. leads to offensive odour.
6. poisonous substances may enter the food chain which is unsafe for man.

Correct Answer: A. Sickle cell anaemia

Correct Answer: B. lack chlorophyll

Explanation

(a)(i) Co-dominance: Co-dominance occurs when both the alleles in an heterozygous individual are fully expressed; that is both alleles exert their effects so that the hybrid has a phenotype; that is different from what the parents exhibit.

(ii) Calculation of individuals with co-dominant blood group:Mention of co-dominant blood group is AB. Evidence of calculation 32.8% of 250 OR 32.8/100 x 250 = 82 individuals/ people.

(iii) Total number of individuals that can donate blood to blood group B: The total number of individuals will be from groups B and 0.

—14% of the population is Blood group B 14% of 250 OR 14/100 x 250 = 35 individuals/people.

— 45.2% of the population is Blood group 0 45.2% of 250 OR 45.2/100 x 250 = 113 individuals/people.

— Total number of people = 113 of group 0+ 35 of group B = 148 Individuals/people can donate blood to the accident victim in B. OR The total number of individuals from (B and 0) blood group B and 0

— 14% + 45.2 = 59.2%.

— 59.2% of 250. 592/100 x 250 = 148 people/individuals.

Correct Answer: B. bending the arm, the biceps contract and the triceps relax

Explanation

To bend the arm, the biceps contracts and pulls on the radius. Simultaneously, the triceps relaxes.

Correct Answer: C. cabbage