Download Microsoft Word - BIOLOGY M1.doc - KCPE-KCSE

MARAKWET WEST DISTRICT JOINT EVALUATION TEST– 2012 (MAWESSE)
231/1
BIOLOGY
PAPER 1
(PRACTICAL)
JULY/AUGUST - 2012
MARKING SCHEME
1.
Genes; Environment. Acc. Any correct example of environmental factor e.g. light, nutrition
e 2.
Salts acts by osmosis; to remove the water needed by the cytoplasm to function;
3.
(i)
Holds the cell together / keeps protoplasm of the cell separated from the outside
environment;
4.
(ii)
Helps to control the movement of materials into and out of the cell.
(i)
Salivary amylase is denatured by hydrochloric acid in the stomach;
(ii)
5.
High temperature above optimum; extreme PH
Any one
In a predation, an organism kills another for food. While in parasitism, an organism depends on
another for fodd while causing harm without killing it;
6.
(a)
Protoctista;
(b)
Flagellum;
(c)
Disease – Sleeping sickness;
Vector - Tsetsefly;
7.
the
Organisms produces more offspring than can survive / overproduction of offspring by
individual with superior characters making them more prevalent;
-
Variations arise in the population;
-
Elimination of certain variations i.e the less fit to survive or those with inferior
characters;
-
Some variations make it possible for members of a population to survive and reproduce
more successfully;
-
Over time, offspring of individuals with favourable / helpful variations make up more of
a
population and maintaining of species identity by the isolating mechanisms.
8.
Resolution (Enabling two points that are close together to be viewed as separate objects); 9.
-
Fast loading and offloading carbon (iv) oxide because of presence of carbonic
amydrase;
-
The PH of he blood is not altered as hydrogen ions readily combine
with haemoglobin.
10.
(a)
Xylem;
(b)
Cross walls between successive vessel elements are performed, giving free passage of
water from cell to cell;
-
There is dissolution of cross walls within the vessel elements thus forming an
open tube along the axis of the organ;
11.
(a)
(b)
-
Thick (cellulose ) / lignified wall / rings prevents collaps (under tention;
-
Lack of long contents / hollow / empty allows free flow
-
Wide lumen / cavity to ease flow / large volume;
-
Stacked end to end / elongated forming a continuous tube.
Negative phototaxis
It enables the maggots to move away from light hence prevent excessive water loss by
evaporation; and escape predators (by hiding away)
12.
Have aerenchyma tissues; Lacks cuticle
13.
Bring about exchange of genetic materials which leads to variations; that enable the organism to
exploit new environment/ have resistance to diseases / high yields / hybrid vigour; due to
mixing of genetic materials;
14.
15.
-
Do not have produces/ producer missing
-
Lizard to chicken energy flow is reversed;
(a)
the
Refers to a cross of unknown parent genotype with genotype homozygous recessive of
same trait; importance: Identifies the genotype of unknown parent;
(b)
(Either) all off springs show the dominant characteristics; or half offspring show the
recessive while the other half show the dominant character.
at the start
at the end
16.
(a)
it was placed in a hypertonic solution; it lost water by osmosis and became crenated;
At the start of Pasmolysis
At the end of plasmolysis
17.
18.
(i)
Protandry / protogyny / male and female parts mature at different times;
(ii)
Dichogamy / stigma positioned higher than stamen / Heterostyly;
(iii)
Incompatibility / self sterility;
(i)
Homoiotherm animals can be active both during the day and at night;
(ii)
Because they can be also active in both hot and cold climates, they are able to live in
any
part of the word / can be widely spread in the community.
19.
(a)
(b)
Arthropoda
(i)
(ii)
rej Arthropod or Anthropoda
Serves as protection –
-
against predators
-
Water loss from body
-
Support – serves as point of muscle attachment at the joints possible.
Disadvantage – Limits growth;
20.
Beak
Talon
(i)
Carnivorous;
(ii)
-
Sharp / hard / strong / curved/hooked beaks; for seizing tearing prey / flesh
-
Sharp / curved/hooked/strong claw; for securing / capturing / killing / carrying
prey;
21.
22.
-
Small intestines (in absorption of digested food)
-
Kidney (in selective re – absorption);
-
Nutrients in he water cause entrophication leading to proliferation of plants / algal
bloom;
-
It blocks light from reaching plants underneath inhibiting
photosynthesis;
-
The plants die leading to proliferation of aerobic saprophytic organisms, which deplete
oxygen in water;
23.
-
Aquatic animals die of suffocation;
per
Centipedes have one pair of legs per body segment, millipedes have two pairs of legs
body segment
-
Centipedes have dorso – ventrally flattered body, millipedes have cylindrical body;
-
The body of a centipede is divided into two parts – head and trunk while in millipede it
is
divided into three body parts – head, thorax and trunk;
-
Centipede has poison claws on the head while centipede has no poison claws;
-
Centipedes are carnivorous, millipedes are herbivorous any first 3
24.
-
Xylem; Sclerenchyma; Collenchyma; Turgid parenchyma;
25.
(a)
Anaerobic micro – organisms breakdown organic substances in the sewage
Sprouty of lateral buds;
(b)
26.
(i)
(ii)
27.
Baking bread; Brewing alcoholic drink
Nourish the sperm cells
Secrete Androgens / testosterone;
(a)
adulthood.
(b)
It is the change in shape / structure / appearance during development to
-
It allows the insects to survive unfavourable conditions.
-
In complete metamorphosis the larva occupies a different niche thus increasing the
chances of survival.
28.
(i)
(ii)
29.
Diffusion
Use of contractile vacuole / pinocytosis rej. Phogocytosis,
Population is the / groups total number of all members.
Organisms of a species occupying a given habitat and animals in a given area / habitat and
interacting / co-existing / living – with each other.
30.
The source of auxins is removed; less hormones on lateral bud promote sprouting of many
lateral buds into side branches
-
Prevents apical dominance; less growth hormones concentrate on lateral buds; cell
division occurs on lateral buds cell division occurs on lateral and resulting in the source
of auxins