I have concluded the final part of the first topic before moving on to the next topic, I will be posting questions related to this topic from jamb past questions later today.. STAY TUNED and don't forget to hit the share button you don't know who might benefit.. Thanks for following
Life exist in an organised form so as to carry out efficiently the characteristics of living things.
Organisation of life is the existence of life from a single-celled organism to a multicellular organism with complex forms that perform different functions
Four level of organisation exist :-
1. Cell :- some living exist as a cell capable of carrying out all the characteristics of living things. Eg Amoeba Chlamydomonas Paramecium and
Euglena
2. Tissues :- A tissue is a collection of cells which are similar in structure and perform similar functions. Hydra Is an example of animal that is made up of tissues only. examples are blood, epithelial skeletal etc
3. Organ :- An organ is a collection of different tissues that perform a common function or functions. Example of organs are heart, roots, kidney etc
4. System :- A system is a set of organs which co-operate to carry out one vital functions of life. Eg digestive system, reproductive system etc
The nucleus is considered the control organelle of a cell because itA. contains the genetic material B. contains the nuclear sap C. is bounded by the nuclear membraneD. is located at the centre of the cell. (A)
2.The procaryotic cell type is characterized by aA. complex cytoplasm in which different regions are poorly defined . B. localization of differ regions of the cell into tissues. C. collection of organelles and macromolecular complexes D. simple cytoplasm with well-defined regions.(A)
3.The natural tendency of organism as they evolve is toA. decrease in size B. increase in number C. develop specialized structures D. feed indiscriminately. (C)
4.In snails, the hard calcareous shells are secreted by theA. radula B. ctendium C. pneumostome D. mantle (A)
5.The ability of the cockroach to live in cracks and crevices is enhanced by the possession ofA. wings and segmented body B. compound eyesC. claws on the legs D. dorso-ventrally flattened body. (D)
6.The case of termites that lacks pigmentation is theA. kingB. worker C. solder D. queen. (D)
7.The structures that prevent food particles fromescaping through the fish gills are called gillA. arches B. filaments C. rakers D. lamellae.(C)
8.A distinguishing feature of mammals is the possession ofA. skinB. scaleC. nailD. hair.(D)
9.Which of the following structures is capable ofproducing more tissues in the stem of a herbaceousflowing plant?A. Epidermis B. Pericycle C. Xylem D. Cambium.
10.The manufacture of carbohydrates by plants takesplace only inA. the leaves B. the green stemsC. chlorophylous parts D. flowering plants (C)
11.In a water culture experiment, a plant showed poorgrowth and yellowing of the leaves. These may be dueto deficiency of A. copper B. iron C. magnesium D. calcium.
12In million’s test, when the reagent is added to a proteinfood item, a white precipitate is produced which turnsA blue on heating B. yellow on heatingC. green on heating D. red on heating.
13Regulation of blood sugar level takes place in theA. pancreas B. ileumC. liver. D. kidney.
14Unicellular organisms transport essential nutrientsdirectly to all parts of their bodies by the process ofdiffusion because, they haveA. a large volume to surface area ratio B. a large s urface area to volume ratio C. their bodies immersed in the nutrients D. their outer membrane made of cellulose.
15.The heat of the adult frog consists ofA. two auricles and two ventricles B. one auricle and one ventiricle B. one auricle and one ventricleC. two ventricles and one auriclesD. one ventricle and two auricles.
Good morning everyone, someone said it's
better I post the questions without options...
Are we up for some challenges this morning?
1. Element common to protein, carbohydrate
and lipid is__________
2.The crown of the mammalian tooth is
covered with.
3. In living cells, insufficient oxygen may
cause a breakdown of glucose into
4. What the greatest increase in the rate of
transpiration
Waiting for answers
Organelles(cell structure) are the functional unit of a cell their functions are as follows
1. NUCLEUS:- it's d largest cell organelle surrounded by two membrane(envelope).
D nucleus contains chromatin (chromosomes) which house d DNA which is organised into genes. Genes controls the activities of the cell.
The cell also contains the NUCLEOLUS that manufacture ribosomes.
2. CENTRIOLES:- centriole is found only in the animal cell, they grow into spindle fibres during nuclear division
3. ENDOPLASMIC RETICULUM(ER) :- they are two types of ER-the smooth ER and the Rough ER.
The rough ER have ribosomes attached to it while the smooth ER does not.
the rough ER help in transporting proteins formed by the attached ribosomes while the smooth ER makes lipid and steroids
4. GOLGI APPARATUS:- the apparatus collects, processes and sorts molecules ready for transport in GOLGI VESICLES.
5.LYSOSOMES:- they contain hydrolytic(digestive) enzymes which helps in breaking down unwanted substances
6. MITOCHONDRIAL :- it carries out the later stages of aerobic respiration which is making ATP.. they are referred to as the energy site they also involve in the synthesis of lipids
7. PLASMA MEMBRANE:- it controls the exchange between cell and its environment.
8. CILIA:- this organelle is also found in animal only. if they are just a few of them they are FLAGELLA.. They help in movement of cells
9. CELL WALL:- helps in keeping the cell rigid..it's present only in plant
10. CHloROPLAST:- site for photosynthesis and found only in plant
Cell is the basic structural and functional unit of life, the [b] protoplasm is the organized complex material of which living cells are made
Cell theory States that
1 . all living things are made up of a cell or cells
2. The cell is the structural and functional unit of all living things
3. New cells arise from pre-existing cells by cell division
Cell structure
Cell is composed of cytoplasm and nucleus(protoplasm)
CYTOPLASM :- it's outside d nucleus and consist of mitochondrial, lysosomes, ribosome, golgi apparatus centrosome and vacoules all bounded by the cell membrane (plasma membrane)
NUCLEUS :- the nucleus is bounded by a thin living nuclear membrane that separates it from cytoplasm. The membranes has tiny pores that allow substances to go in and out of the nucleus.
The nucleus contains nucleolus nd chromatin
The functions of this mention structures (organelles) will be posted next
1.Viruses are considered to be living organisms because theyA. possess transmittable charactersB. move from one place to another C. respond to stimulationD. ingest food materials (A)
2.Which of the following characteristics is common to amoeba and Paramecium?A. Oral groove B. Trichoyst C. Contractile vacuoleD. Cilia (C)
3.Hydra removes undigested food byA. passing it through the anus B. passing it through the mouth C. means of a contractile vacuoleD. egesting it through the body surface. (B)
4.Which of the following groups of invertebrates reproduces by budding A. ArthropodaB. Annelida C. MolluscaD. Coelenterata. (D)
5.The algae, bryophytes and pteriodophytes aresimilar in that theyA. are sea weeds B. have no vascular tissuesC. require moisture for fertilizationD. are microscopic plants. (C)
6.The spores of ferns are dispersed byA. wind
B. water C. insects D. explosive mechanism (D) .
7. In bryophytes, sex organs are produced in the A. gametophyte B. rhizoid C. protonema D. sporophyte (A)
8. Which of the following animals has homodont dentition? A. Rat B. Man C. Lizard D. Pigeon. (C)
9. In which of the following does external fertilization take place? A. Toad B. Lizard C. Bird D. Cockroach. (A)
10. In the tapeworm, the suckers on the scolex are used for A. sucking the blood of the hostB. holding fast to the host C. reproduction D. locomotion (B)
11. A feature which adapts birds to flight is the possession of A. scally legs B. light bones C. two walking legs D. a.pointed beak. (B)
12. The nephridia in the earthworm form part of the A. reproductive system B. respiratory system. C circulatory system D. excretory system. (D)
13.Which of the following diseases is rarely spread by a housefly? A. Yellow fever B. Dysentery C. Typhoid fever D. Poliomyelitis (A)
14. Which of the following cells is thin-walled and living at maturity? A. Collenchyma B. Sieve tube C. Xylem vessel D. Sclerenchyma. (B)
15. The mode of nutrition in which digestion is extracelluar is A. holophytic B. parasitic C. holozoic D. saprophytic. (D)
TO BE CONTINUED...
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