Random Important Points

Question 1

State 3 main ways by which man influences the cycling of carbon in nature?
(2009)

Answer 1

1. Burning of fossil fuels
2. Lime industry / burning of CaCo3
3. Deforestation

Question 2

Elements which act as enzyme activators?

Answer 2

Mg
K
Ca
Cl
Cu
Zn
Mn

Question 3

Myentric / Auerbach’s plexus

Answer 3

Location: Between circular and longitudinal smooth muscles of muscularis externa.
Function: Control the contractions of muscles of muscularis externa (peristalsis)/.

Question 4

Submucosal/Meissner’s plexus

Answer 4

Location: Submucosa
Function: Control glandular release of submucosa and mucosa.

Question 5

What are some substances absorbed in the stomach?

Answer 5

Alcohol
Water
Minerals
Some drugs

Question 6

Name a hormone secreted by the stomach?

Answer 6

Gastrin
Site of production: Stomach mucosa
Stimulus: Stretching stomach by food
Response: Increase secretion of gastric juice/HCl

Question 7

What is the type of cells present in mucosa epithelium?

Answer 7

Simple columnar epithelium

Question 8

What is natural classification?

Answer 8

Grouping of organisms based on evolutionary relationships.

Question 9

Name some taxonomic criteria that are based on present system of classification?

Answer 9

1. Sequence of bases of DNA of important genes.
2. DNA of mitochondria
3. The base sequence of ribosomal RNA
4. The sequence of amino acids in common proteins
5. Molecular structure of cellular components.

Question 10

Examples of organisms of K-Protista

Answer 10

Phy Ciliophora: Paramecium
Phy Rhizopoda: Entamoeba histolytica. amoeba
Phy: Chrysophyta: Diatoms, Pinnularia, Naviculata
Phy Phaeophyta: Sargassum, Macrocystis, Laminaria
Phy Rhodophyta: Gelidium, Porphyra
Phy Chlorophyta: Chlamydomonas, Spirogyra, Ulva, Cosmarium

Question 11

What are some unique features of Phylum Chordata?

Answer 11

• A rod like dorsal notochord present in adults or at least during some developmental
stages
• A single, dorsal hollow nerve cord
• Pharyngeal gill slits are present at some developmental stage
• Post-anal tail is present in adults or at least during some developmental stage
• (?) Closed circulatory system with a ventral heart
• (?) Coelom well developed
• (?) Skeleton if present, is an endoskeleton formed by mesoderm
• (?) Sexes usually separate, oviparous, ovoviviparous or viviparous

Question 12

What is a respiratory surface?

Answer 12

Area where gas exchange takes place with the environment.

Question 13

What are the functions of surfactant?

Answer 13

1. Prevent collapsing of alveoli
2. Keep air exchange surface wet
3. Prevent flowing of intercellular fluid during expansion of lungs.

Question 14

What is meant by transpiration?

Answer 14

Transpiration is the loss of water vapour from the (aerial parts of) plant mainly through stomata and to some extent
through lenticels and cuticle.

Question 15

What are some internal factors affecting transpiration?

Answer 15

♣ Number and distribution of stomata
♣ Internal structure of leaf 
• Total area of leaves of the plants
• Arrangement/ direction of leaves
• Thickness of cuticles
• Presence of hair on the epidermis
• Multiple epidermises
• Bearing sunken stomata
• Width or the diameter of stoma
♣ Amount of water in plant
♣ CO2 concentration in substomatal cavity

Question 16

What are some substances transported in phloem?

Answer 16

Organic

• Sucrose
• Amino acids
• Vitamins
• Plant growth substances
• Chemicals applied to plants

Inorganic

• K+
• Phosphate

Question 17

What is the value of blood glucose in a normal healthy adult human?

Answer 17

80-120 mg/100ml

Question 18

What are the excretory products which result due to matabolism of carbohydrates. fat, proteins and nucleic acids?

Answer 18

Carbohydrates: Aerobic - CO2 + H2O Anaerobic - Lactic acid
Fat - CO2 + H2O
Proteins - NH3 + CO2 + H2O
Nucleic acids - NH3

Question 19

Classes of Arthropods possessing malphigian tubules for excretion

Answer 19

Insecta
Chilopoda
Diplopoda
Arachnida (+coxial glands)

Question 20

2 types of network of capillaries are found around a nephron. What are they?

Answer 20

1. Glomerulus

2. Peritubular capillaries

Question 21

Mention a structural adapation of Bowman’s capsule to increase efficiency of ultrafilteration?

Answer 21

Inner epithelium cells called podocytes are present which have cell bodies with numerous projections which can act as filtration slits.

Question 22

Mention some substances absorbed in PCT and DCT?

Answer 22

PCT
Active: glucose, amino acids, Na+
Passive: Water, urea, Cl-, K+, HCO-

DCT
Active: Na+ (Ca2+)
Passive: Cl-, HCO3- Water (in the presence of ADH)

Question 23

What are the componds contained in glomerular filterate though not available in urine of a healthy person?

Answer 23

Glucose
Amino acids
HCO3-

Question 24

Organisms possessing hydrostatic skeleton?

Answer 24

Annelids

Nematodes

Question 25

What is a hydrostatic skeleton?

Answer 25

A fluid secreted within the body is enclosed by the body wall which is composed of two muscle layers (longitudinal and circular) which act antagonistically. The combined effect of muscle contraction and fluid pressure aids in locomotion and maintain the shape and form of the animal.

Question 26

Organisms possessing exoskeleton?

Answer 26

♣ Coelenterates - Calcified exoskeleton ( some anthozoa)
♣ Some unicellular animals - Calcium and silica (Radiolaria, Foraminifera)
♣ Molluscs - Calcified
♣ Arthropods - Chitinous ; Crustaceans - CaCO3

Question 27

Examples of sex linked characteristics in human?

Answer 27

Haemophilia
Colour blindness
Duchenne’s muscular dystrophy