Biology 2017 Theory
1. (a)
(i) What is classification of living things?
(ii) Name the scientist that developed the Binomial Sys-tern of Classification
(iii) State three reasons why it is necessary to classify living things
(iv) List seven major groups into which taxonomists classify living things in order of hierarchy
(b) state two features each which viruses have in common with: (i) living things
(ii) non-living things
(c) Name two viral disease each of:
(i) plants
(ii) humans
Solution & Explanation:
Classification of Living things: Is the sorting/ grouping/arranging of living things (in groups); according to their common/similar characteristics/features/shared qualities.
(ii) The scientist who developed the Binomial system of classification: Carl/Carolus Linnaeus/Linnaeous
(iii) Reasons for classification of living things
- To put every lying organism into a systematic order/ specific group
- for easy identification of similar living things
- to indicate/Show the relationships between different categories of living organisms
- to show evolutionary trends in different groups of living organisms
- to trace geographical distribution of living organisms
- for easy reference
- for easy research/study.
(iv) Classification of ranks in order of hierarchy
Kingdom
Phylum/Division
Cass Order
Family
Genus
Species.
Features of Viruses as (i) living things (ii) nonliving things
(i) Living things
- has protoplasm/protein coat/membrane
- contain DNA/RNA/Nucleic acid
(ii) Non-living things
- appear as crystals
- lack of organelles
(c) Viral diseases of:
(i) Plants:
- Cassava mosaic disease
- Bean mosaic diseases
- cacao swollen shoot disease
- Groundnut rosette
- maize streak
- cucumber mosaic
- any correctly named disease.
(ii) Humans;
- poliomyelitis/polio
- chicken pox
- mumps
- measles
- influenza/flu
- AIDS
- Ebola disease
- infective hepatitis
- Lassa fever
- Avian influenza (Bird flu)
- Swine flu (Bovine flu)
- Rabies
- Zika
2. (a) State four characteristics of enzymes
(b) (i) List two digestive enzymes produced in the duodenum of humans
(ii) Name the substrate that each enzyme listed in 2(b)(i) acts on.
(iii) State the products of each enzyme activity in 2(b)(ii)
(c) (i) State one way in which chlorophyll is important in plants
(ii) Name two macroelements that are required for the formation of chlorophyll in plants.
(iii) State one deficiency symptom of each macroelement named in 2 (c) (ii) above
(d) Outline the proce-dure used for testing for starch in a leaf
Solution & Explanation:
(a). Characteristic of Enzymes;
- They are biological catalystsialter/speed up the rate of biological reactions
- remain chemically unchanged at the end of a reaction
- their actions are reversible
- they are specific in action/act on specific substrates
- enzymes are required in small amount
- are protein in nature
- they act best at optimum temperature/high temperature/denatures them/ low temperature inactivates them
- specific/sensitive to pH
- actions retarded by poisons/inhibitors
- some required co-enzymes to function.
(b)i. Digestive enzymes produced in the duodenum of humans
- Amylase
- Trypsin/chymotrypsin
- Lipase
ii. Substrates for each enzyme
- Amylase = starch
- Trypsin/chymotrypsin =protein
- Lipase = fats and oil
iii. Product of enzyme activity
- Amylase = maltose
- Trypsin/chymotrypsin = peptones/polypeptides/peptide
- Lipase =glycerol and fatty acid
(c)i. Importance of chlorophyll in plants
Absorbs/traps sunlight; for photosynthesis
ii. Macro-elements required for the formation of chlorophyll
- Nitrogen
- Magnesium
- Iron
iii. Deficiency symptoms of each macro-element in (c)ii
Nitrogen
- Chlorosis/yellowing of leaves
- Stunted growth
- Poor flower/fruit development
MagnesiuM
- Poor growth
- Chlorosis/yellowing of leaves
Iron
- Poor/stunted growth
- Chlorosis/yellowing of leaves
(d) Procedure for test for starch
- Detach/pluck off/take leaf to be tested from plant after 4 to 6 hours of exposure to sun to enable it to form starch
- Put leaf in boiling water for about 30 seconds to kill the cells
- Put boiled leaf in 70% warm alcohol/ethylated spirit in water bath to decolorise the leaf Rinse decolorised/brittle leaf in running cold water to soften the leaf tissues/remove alcohol
- Spread out on white tiles/watch glass and add a few drops of iodine solution
- Allow to stand for a few minutes
- It turns blue-balck showing/indicating presence of starch.
3. a) Name one instrument used for collecting:
(i) soil organism from a soil sample
(ii) tiny insects from a leaf or a stem.
(b) make a diagram 6 cm – 8 cm long of the instrument named in (a)(ii) above and label fully.
(c) Explain briefly the relationship between three examples of symbiotic organisms
Solution & Explanation:
(a)i. Instrument for collecting soil organisms from a soil sample
- Sieve
- Tullgren funnel
ii. Instrument for collecting tiny insects from a leaf or stem
- Pooter
(b) Diagram/drawing of pooter
Quality (0)
Stopper/rubber bung with two openings (RO) x1
Two delivery tubes one longer than the other x1
Inner end of shorter delivery tube with mesh/gauze(IM) x1
(c) Symbiotic relationships in organisms
Trichonympha Protozoa living in the gut of a termite;
Helps the termite to digest cellulose; while the protozoa trichonympha gets protection and food in return from the termite.
Sea anemone attaching itself to the shell of hermit crab; thereby enjoying pieces of leftover food therein. The hermit crab in turn enjoys protection against predators/ the sea anemones stings prevent the predators from harming the hermit crab.
Algae and fungi in a lichen; Lichen is made up of a fungus and a unicellular alga living together. The green alga produces food/photosynthesis for the association; the fungus protects the alga/absorbs water from the surrounding.
Rhizobium sp Nitrogen- fixing bacteria and root modules of leguminous plants. The Rhizobium fixes atmospheric nitrogen directly into the plant while rhizobium enjoys shelter/food/nutrients from the plant.
4. (a) A child belongs to blood group 0 and the mother be-longs to group B. With the aid of genetic cross, state the possible blood groups of the father.
(b) (i) Name two forms of adaptive communication in animals
(ii) State two reasons why organisms communicate with one an-other.
Solution & Explanation:
A child belongs to blood group 0 and the mother be-longs to group B. With the aid of a genetic cross. State the possible blood groups of the father
(a) Genetic cross
If the father is group A
(b)i. Forms of adaptive communication
- Sound/auditory/acoustic
- visual; smell/chemical/ pheromones
- tactile
- electrical signal
- display.
ii. Reasons why organisms communicate with one another
- for food
- maiting/reproduction
- territorial defence
- danger/threats/predator
- tracking routes.
5 (a) Explain briefly the process of perceiving smell in humans.
(b) State the adaptive features of the egg of a domestic fowl
(c) (i) What are autotrophs?
(ii) Name two unicellular organisms that are autotrophs
(d) State five functions of the World Health Organisation
(e) Name two example each of plants and animals that live in a freshwater pond.
(f) In the table below, state five differences between the skin of a mammal and the epidermis of a leaf.
(g) A farmer has two plots of land; plots A and B. on Plot A the farmer planted several seeds of maize. On plot B, the farmer planted several seeds of maize and pepper in a small area. What type of competition would be observed on
(i) Plot A
(ii) Plot B
normal and 50% albino offspring?
Solution & Explanation:
(a) The process of perceiving smell
- Chemical substances/odour carried in the air pass through the air/nasal cavity
- The molecules dissolve in the moist membrane of the nasal cavity
- Sensory cells are stimulated
- Impulses are formed
- which pass through the nerves ending to the olfactory nerves
- which pass into the cerebrum of the brain/brain
- The brain interprets the impulses
- And the sensation of smell is produced/smell is perceived
(b)Adaptive features of the egg of a domestic fowl;
Porous: shell; for gaseous exchange/provides shelter/ protects the embryo against mechanical damage/ desiccation
Shell membranes; allow gaseous exchange/for protection
Yolk; contains high level of proteins and fats/provides food for embryonic-growth
Egg white/albumen; consists of water to absorb shock/ proteins/food
Air space; provides surface for gaseous exchange Chalaza; holds the yolk/embryo in position.
(c)i. Autotrophs: Organisms that do not rely on other organisms for food/they manufacture their own food; from using simple inorganic compounds; can be chernosyn-thetic/photosynthetic
ii. Examples of unicellular autotrophs Clamydomonas; Euglena; chemosynthetic; bacteria/ sulphur, bacteria; blue-green; algae/Anabaena; Nostoc/ Oscillatoria; Chlorella diatoms; Nitrosomonas; Nitrobacteria
(d) Functions of WHO
- provides grants for medical research
- Improves public health/promotes environmental health
- prevents the spread of diseases vaccination
- provides vaccines/drugs in cases of emergencies
- Informs/creates awareness/educates the public of any research findings/outbreak of diseases
- Assists by sending medical personnel/logistical sup-port to countries upon request
- Helps in the training of medical personnel
- keeps health statistics
- promotes nutritional/sanitary products.
(e) Examples of plants and animals that live in fresh water pond
Plants: Water arum; diatoms; Ceratophyllum/hornwort; utricularia/bladderwort. Arrowhead/sedge; Pistia; Salvinia/water fern; water lily; wolffish/duckweed any other correctly.
Animals: Cyclops; Daphnia/water flea; Hippopotamus; crocodile; water snake; tadpoles; pond skaters; zooplanktons; mosquito larvae; water bugs; water scorpions; leeches; water snails; catfish/Tilapia fishes etc.
(f) Differences between skin of a mammal and epidermis of leaf
skin of a mammal | Epidermis of leaf |
skin is made up of many layers/cells | made up of a single layer/cells |
presence of sweat gland | absence of sweat gland |
presence of sebaceous gland | absence of sebaceous gland |
Absence of cuticle | presence of cuticle |
Absence of guard cell stomata | Guard cells are present / stomata |
Has blood cells capillaries | absence of blood vessels / capillaries |
synthesizes vitamin D | does not make vitamin D |
Fatty cells are present | absence of fatty cells |
It is a sensory organ | its not a sensory organ |
Hair follicle present | hair follicle absent |
erector muscle present | erector muscle absent |
presence of sweat pore | absence of sweat pore |
(g) Type of competition on
(i) Plot A: intra specific/intra species competition
(ii) Plot B: interspecific/interspecies competition
love these