makethegrades:
Is

R.D = Wt. Of substance in air / wt. Of equal volume of water
Since Hooke's law is obeyed we use the extension in place of weight.
We have extension of the metal in air
We also have extension of metal in water but we don't have weight of the water that is equal in volume to the metal
So use Archimedes principle 'upthrust = weight of fluid displaced' to get the weight of equal volume of water
Upthrust= wt. in air - wt. In water
= 10.5 - 6.8
= 3.7 cm
> wt. Of equal volume of water = 3.7 cm
Applying R.D formula
R.D = Wt. Of substance in air / wt. Of equal volume of water
= 10.5/3.7
= 2.84

Pes13:
Biology

1. The center for learning and memory in the human brain is the A) olfactory lobe B) cerebrum C) medulla oblongata D) cerebellum.



2. The physical space occupied by an organism together with its functional role in the community can be described as A) niche B) environment C) habitat D) biome.

3. The hygrometer is used for measuring A) rainfall B) relative humidity C) salinity D) specific gravity.

4. The highest percentage of energy in an ecosystem occurs at level of the A) producers B) primary consumers C) secondary consumers D) decomposer.

5. Carbon (IV) oxide content of the atmosphere is least affected by A) burning of fossil fuel B) cutting down and clearing of forests C) plant and animal respiration D) forest fires.

6. A freshwater pond may contain A) pond skater, water lily, shark and mosquito larva B) water lily, fish water scorpion and dragonfly larva C) tad pole, water boatman, leeches and crab D) water beetle, shrimps, water snail and water bug.

7. The epiphytic habitat can best be described as A) aquatic C) arboreal B) terrestrial D) estuarine.


8. The distribution of plants in a rain forest is governed mainly by A) rainfall pattern B) vegetation C) soil types
D) amount of sunlight


9. The number of plant species obtained from a population study of a garden is as follows; Guinea grass (15), Ipomea spp. (5) Sida spp (7) and Imperata spp. (23). What is the percentage of occurrence of Imperata spp.? A) 16% B) 23% C) 35% D) 46%.

10. The greatest influence on a stable ecosystem in nature is excreted by A) rainfall B) animals C) man D) pollution.

11. The factor the least affects food shortage in sub-saharan Africa is A) drought B) flooding C) pests D mixed – cropping

12. In man, the ability to roll the tongue is a variation classified as A) structural B) morphological C) anatomical D) physiological.

13.Which of the following statements is true of blood groups and blood transfusion? A) Group A can donate to group A only B) Group B can donate to group B only C) Group O is the universal recipient D) Group AB is the universal recipient

14. A tall plant crossed with a dwarf one produces offspring of which half are tall and half are dwarf. What are the genotypes of the parents? A) Tt, tt D) TT, TT. B) TT, tt C) Tt, Tt


15. Both recessive and dominant characters are found A) at the same locus of a homologous chromosome B) at different loci of homologous chromosome C) on different chromosomes in the cell D) on the same chromatid in a chromosome.

16. which of the following is likely to encourage inbreeding in plants A) monoecious B) dioecious C) hermaphrodite
D
protandrous.

17. The probability of a baby being a boy or a girl depends on the contribution of the A) mother’s sex cell B) mother’s X chromosome C) father’s sex cell D) father’s somatic chromosome.

18. The ability of an organism to live successfully in an environment is known as A) succession C) adaptation B) resistance D) competition.

19. For heterotrophic organisms, competition is least caused by inadequacy of A) nutrients B) light C) space D) mates

20. The most important adaptation of xerophytes is the ability of the protoplasm to A) absorb water and swell B) resist being damaged by loss C) shrink from the cell wall D) store sugar and minerals in the vacuoles.

21. The stem of a typical aquatic plant usually has many A) water cavities
B) water-conducting cells C) air cavities D) intercellular spaces.


22. A green snake in green grass is able to escape notice from predators because of its A) warning colouration B) disruptive colouration C) cryptic colouration
D) countershading.

23.The role of the male adult honey bee is to A) mate with the queen B) care for the young C) clean the hive D) ventilate the hive.

24.Darwin is considered the first scientist who correctly explained the theory of A) organic evolution B) use and disuse C) special creation D) spontaneous generation.

kidneystones:


I think the correct option for 14 is A

overcomer90:


All answers are correct but l am not sure of number 5 I think it is C

Drbabalola:
the answer should be (B). Using logical reasoning,( a medically proven fact for men) as opposed to analytical reasoning, a (medically proven fact for women). all the listed factors affect the level of atmospheric Co2 in one way or other; but the question says: the factor that least affects the level of atm. Co2. Option (B) is correct because it is a RANDOM factor and only depends on MAN as to whether or not trees would be cut. But option (C ) is wrong because PLANTS AND ANIMALS respire constantly and thus pose significant effect to the level o atmospheric Co2. I hope you get this? Love you!

Hipprocrates:
Kidneystones, abeg add me too. 08144843593

akanbidamilare:
Am presently reading carbon and its compounds.
pls is it really necessary to also learn the
laboratory preparation
chemical properties
physical properties
test
reactions
for CO2, CO, CO3 etc
cos it seems difficult to cram
how do u guys learn those stuffs pls?

boyejo123:


what of no.10 sir
i think it should be rainfall since rainfall serves as means of excreting excess co2 and water in the atmosphere but av seen many people choose MAN .
how does man excretion brings about stable ecosystem

Pes13:

My brother, u must know everything.
MIMD you, if you cram, there is high tendency you forget.
Enjoy and understand it, it not hard. You will love it.

akanbidamilare:
Am presently reading carbon and its compounds.
pls is it really necessary to also learn the
laboratory preparation
chemical properties
physical properties
test
reactions
for CO2, CO, CO3 etc
cos it seems difficult to cram
how do u guys learn those stuffs pls?

makethegrades:
Is

R.D = Wt. Of substance in air / wt. Of equal volume of water
Since Hooke's law is obeyed we use the extension in place of weight.
We have extension of the metal in air
We also have extension of metal in water but we don't have weight of the water that is equal in volume to the metal
So use Archimedes principle 'upthrust = weight of fluid displaced' to get the weight of equal volume of water
Upthrust= wt. in air - wt. In water
= 10.5 - 6.8
= 3.7 cm
> wt. Of equal volume of water = 3.7 cm
Applying R.D formula
R.D = Wt. Of substance in air / wt. Of equal volume of water
= 10.5/3.7
= 2.84

boyejo123:


what of no.10 sir
i think it should be rainfall since rainfall serves as means of excreting excess co2 and water in the atmosphere but av seen many people choose MAN .
how does man excretion brings about stable ecosystem

boyejo123:


what of no.10 sir
i think it should be rainfall since rainfall serves as means of excreting excess co2 and water in the atmosphere but av seen many people choose MAN .
how does man excretion brings about stable ecosystem

Pes13:


You are right, it is not amount of sunlight

Salarys:


Wow...you just brought my attention towards EXCRETED.. nonetheless if that is the case, pollution should be the greatest influence that affects its stability from CO to CO2 to CFCs to the depletion of the ozone layer etc ... I think so!

How does rainfall serve as a means of excreting excess CO2 sir?

Salarys:


Sir, I believe this is for question 14.

Isn’t the rainfall pattern in rainforests even all through... considering that I thought the distribution of plants should then be mainly dependent on the amount of sunlight..

Please shed more light

Pes13:


I uses to think sunlight was d answer, but after consulting several Past questions in addition to oau putme question and refrence, I was humbled to summit.

One thing is that plant receive adequate sunlight in rainforest, which means sunlight cannot be a limiting factor since they always have more than enough.

But for whatever reason, amount of rainfall is not constant, reason you will see a vague value in textbooks e.g 200-250mm per annum.

sunlight supply is constant and adequate, but rainfall varies even in tropical forest.

Rain fall in Lagos than Abeokuta.

Drbabalola:
I'm very sure my senior medical colleague- Drpes13 made a typing error when writing this question. He typed EXECRETED instead of EXERTED. I expect him to confirm the mistake himself.

akanbidamilare:
what is the difference between homogeneous and heterogeneous mixture?

boyejo123:


wow
if its exerted then it's actually the Man,I concur
but if its excreted I'll go for rain

akanbidamilare:
what is the difference between homogeneous and heterogeneous mixture?

DrBESTJC:
PHYSICS.

In an experiment to determine terminal velocity, as the pressure increases, the viscosity of a liquid...
(A) Increases then decreases
(B) Decreases
(C) Remains constant
(D) Increases.


Please I need explanations.