2020/2021 WAEC/NECO Answers: Neco Gce 2021. Biology answers

(5ai)

(i) Chlorophyll is a photosynthetic pigment found in the chloroplast of some photosynthetic plant. There are two types, these are chlorophyll A and B. 

(ii) Niche is the functional and structural role of an organism in a habitat. Eg A squirrel and a bird lives on the same tree but lives in different condition. A squirrel feeds on nut from the tree, while a wood peckers feeds in insects living in the tree. 

(iii) Phenotype is the physical characteristics of an organism which determines the physical structure and looks of the organism they are mostly affected by the genotype and the environment. 

(5aii) 

(i) Mouth: 

-It contains the teeth used for masticating/chewing food. 

-It contains the salivary glands and enzyme which helps in breakdown of food and dissolving foods for proper digestion 

(ii) Stomach: 

-Stomach secretes acid and enzymes that digest food

-It helps in regulation of the rate at which partially digested food is delivered to the small intestine

(iii) Small intestine:

-Its job is to absorb most of the nutrients and minerals

-It also receives bile and pancreatic juice through the pancreatic duct

(5b)

DRAW A WELL LABELLED MAMMALIA SKIN

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(3ai)

Afforestation can be defined as the process of planting trees, or sowing seeds, in a barren land devoid of any trees to create a forest.

(3aii)

(i)Establishment of game reserve 

(ii)Establishment of zoological gardens 

(iii)Stating or promulgation of bye-law's against killing of wild-life animal's 

(3bi)

(i)Transportation helps the plant to maintain its osmotic potentials

(ii)It cools the plant 

(iii)It prevents plasmolysis and wilting of plant 

(3bii)

(i)Robert Hooks 

(ii)Mathias Schleiden 

(iii)Theodore Schawnn

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(4ai)

(i) Light stage

(ii) Dark stage 

(4aii)

(i) Temperature 

(ii) Rainfall 

(4aiii)

(i) Tick and cattle 

(ii) Mosquito and Human being's skin 

(4aiv)

(i) Fungi and Lichen 

(ii) Rhizobium and leguminisarium plant 

(4b)

(i) By well covering to avoid micro organism from entering it. 

(ii) by putting it in a warm temperature region to avoid micro organism inhabitation

(iii) By sterilizing it if the food has been left exposed

(iv)by digging of gutters 

(4bii)

Genetics is defined as the study of genes genetic variation and heredity in living organisms 

(4ci)

(i)Eardrum 

(ii)Tympanic cavity 

(iii)The footplate 

(iv)Mallevs 

(4cii)

(i)Plant stores complex carbohydrates as starch

(ii)animal store them as glycogen

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(2ai)

reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus.

(2aii)

(i)pineal gland

(ii)pituitary gland

(iii)pancreas

(iv)ovaries

(2bi)

(i)Enzymes are biological catalysts

(ii)They speed up reactions although they are not changed in the reaction

(iii)Enzymes are proteins, and therefore are folded chains of amino acids with a specific shape.

(iv)Enzymes speed up reactions by bringing reactants together and reducing the activation energy required to start the reaction

(2bii)

-Respiration-

(i)It takes place in all the living cells of plant.

(ii)This catabolic process continues throughout the day and night.

(iii)Utilizes oxygen and carbohydrates.

(iv)The end products of respiration are carbon dioxide and water.

(v)The energy released from carbohydrates and other respiratory substrates is trapped in ATP (Adenosine Triphosphate) on oxidation. However, some energy is also lost in the form of heat.

-Photosynthesis-

(i)It takes place only in the cells containing chlorophyll.

(ii)It takes place only in the presence of light.

(iii)Photosynthesis utilizes carbon dioxide and water.

(iv)The end products of photosynthesis are carbohydrates and oxygen.

(v)During photosynthesis, the light energy is converted into chemical energy in the form of carbohydrate.

(2ci)

(i)hydrostatic skeleton

(ii)exoskeleton

(iii)endoskeleton

(2cii)

(i)regulation of PH

(ii)regulation of osmolarity

(iii)production of hormones

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