Today's Test - Biology

Identify A to E .

A- Pronotum, B-Mesothorax, C-Metathorax,D-Tegmina, E-Pleura
A- Pronotum, B-Mesothorax, C-Metathorax,D-Tegmina, E-Sterna
A- Pronotum, B-Mesothorax, C-Metathorax,D-Tegmina, E-Anal cerci
A- Pronotum, B-Mesothorax, C-Metathorax,D-Tegmina, E-Anal style

Cross between unrelated group of organisms is called

Hybrid
Test cross
Back cross
Heterosis

In meiosis –

Division of nucleus twice but replication of DNA only once
Division of nucleus twice and replication of DNA twice
Division of nucleus once and replication of DNA is also once
Division of nucleus once and DNA - replication is twice

The two key concepts of Darwinian theory of evolution are

Use and disuse, and inheritance of acquired characters
Branching descent and natural selection
Branching descent and mutation
Reproductive isolation and mutation

What will happen if ligaments are cut or broken?

Bones will move freely at joints
No movement at joints
Bones will become unfix
Bones will become fixed

Solution

Ligaments are specialised connective tissues which connect bones together, hence if they are cut or broken the bone will be come unfixed.

Test-tube babies are produced by –

Fertilising the egg removed from the body of the female with the husband's sperm outside in vitro culture. Thezygote is transferred back to mother's uterus
External fertilisation and development in vitro culture till 32 cells stage before putting theembryo back into mother's uterus
Complete development of a baby in vitro
Development upto 32 cells stage and transplanting embryo in the uterus ofa surrogate mother

In the homeostatic control of blood sugar level, which organs function respectively as modulator and effector

Liver and islets of langerhans
Hypothalamus and liver
Hypothalamus and islets of langerhans
Islets of langerhans and hypothalamus

Seeds are regarded to be the product of sexual reproduction because they

Can be stored for along period.
Give rise to new plants.
Are the result of fusion of male gamete with the female gamete.
None of these

Lipids are insoluble in water, because lipid molecules are :

neutral
zwitter ions
hydrophobic
hydrophilic

Solution

Lipid is a term used to describe a group of substances in cell, characterized by their solubility in organic solvents such as ether and benzene. These are insoluble in water,because they are hydrophobic.

Procambium form :

Vascular cambium
Vascular tissues
Cork cambium
Intercalary meristem

DIRECTIONS : Each question contains STATEMENT-1 (Assertion) and STATEMENT-2 (Reason). Each question has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.

Statement 1 : UAA, UAG and UGA terminate protein synthesis.

Statement 2 : They are not recognised by tRNA.

Statement - 1 is True, Statement - 2 is True, Statement - 2 is a correct explanation for Statement - 1
Statement - 1 is True, Statement - 2 is True ; Statement - 2 is NOT a correct explanation for Statement - 1
Statement - 1 is True, Statement - 2 is False
Both the Statements are False.

If the forest cover is reduced to half, what is most likely to happen on a long term basis?

Tribals living in these areas will starve to death.
Cattle in these and adjoining areas will die due to lack of fodder.
Large areas will become deserts.
Crop breeding programmes will suffer due to a reduced availability of variety of germplasm.

Solution

If the forest cover is reduced to half, large areas will become deserts, on a long term basis.

The products of protein digestion the amino acids are absorbed in the ileum through –

Lacteals of villi
Blood capillaries of villi
Both (a) and (b)
Muscularis mucosa of villi

What is the fate of the seven cells of the embryo sac ?

All but one disintegrate upon fertilization.
Two become fertilized; the others disintegrate.
Two become fertilized; the others fuse to form endosperm.
All are involved in nuclear fusion events.

In which of the phylum, excretory organs like proboscis glandis present?

Hemichordata
Chordata
Echinodermata
Annelida

Auxin regulates cell growth by

Altering the elasticity of cell walls.
Altering the plasticity of cell walls.
Synthesizing new cell walls.
Breaking down cell walls in growing cells.

Solution

Altering the plasticity allows for permanent changes in cell wall shape. The cell wall must increase in size in order for cell growth to occur.

An enzyme increases the rate of a reaction by :

supplying the energy required to start the reaction.
increasing the rate of random collisions of molecules.
removing the product of the reaction so allowing it to continue.
bringing the reacting molecules into precise orientation with each other.

Solution

An enzyme reduces the activation energy needed for the reaction to occur by binding with a substrate and straining its bonds so allowing for easier reaction, or binding multiple substrates in a way that brings them together in a precise orientation so they can react readily with one another.

The most likely reasonfor the development of resistance against pesticides in insects damaging a crop is

random mutations
genetic recombination
directed mutations
acquired heritable changes

Solution

According to Darwin resistance to pesticides has a genetic basis due to presence of certain alleles. In the presence of pesticides, the insects devoid of the allele for resistance die while the ones having them survive.They are selected by nature.

What is common about Trypanosoma, Noctiluca, Monocystis and Giardia ?

They have flagella
They produce spores
These are all parasites
These are all unicellular protists

Solution

Trypanosoma, Noctiluca, Monocystis & Giardia are unicellular protists i.e. unicellular eukaryotes.

0

0

0

0