MODEL PAPER 6 BIOLOGY - MODEL PAPER 6

The rate of storage of organic matter in producers in excess of their metabolic consumption is:

Phytoplanktons are:

Female hired to develop the in-vitro fertilized egg of another female to maturity is called:

Thermostable DNA polymerase is isolated from bacterium:

In the pedigree analysis, the symbol shown below represent

Assertion (A): Primer pheromones bring about physiological changes in the receivers.
Reason (R): Releaser pheromones cause immediate change in the receivers.

Assertion (A): Our laws permit legal adoption and it is as yet, one of the best methods for childless couples looking for parenthood.
Reason (R): Emotional, religious and social factors are also no deterrents in the legal adoption of orphaned and destitute children in India.

Assertion: Statins is a blood-cholesterol lowering agents.
Reason: It inhibiting the enzyme responsible for synthesis of cholesterol.

Assertion (A): Evolution of man is the example of progressive evolution.
Reason (R): Tapeworm is developed due to retrogressive evolution.

Mention the product and its use produced by each of the microbes listed below
(i) Steptococcus
(ii) Lactobacillus
(iii) Saccharomyces cerevisiae

a. Cattle excreta is important source for producing a domestic fuel. Name the fuel and write its main components.
b. Write the biological process that is responsible for the production of this fuel.

Name the labels A, B, C, D, E and F in the diagram of seminiferous tubule.

What is the function of the two male gametes produced by each pollen grain in angiosperms?

Study the figure given and answer the questions.

i. How does the repressor molecule get inactivated?
ii. When does the transcription of lac mRNA stop?
iii. Name the enzyme transcribed by the gene z.

Answer the questions based on the dinucleotide show below.

i. Name the type of sugar to which guanine base is attached to.
ii. Name the linkage connecting the two nucleotides.
iii. Identify the 3' end of the dinucleotide. Give a reason for your answer.

Which one of the two in-situ or ex-situ biodiversity conservation measures help the larger number of species to survive? Explain.

With the help of three examples, explain the broadly utilitarian argument for conservation of biodiversity.

Differentiate between an Expanding age pyramid and a Stable age pyramid. Substantiate your answer with diagrams.

Name and explain the two types of immune responses in humans.

State the similarity and differences between geitonogamy and xenogamy. Why do cleistogamous flowers assure seed sets?

Recombinant DNA vectors are typically attenuated viruses or bacteria that are unrelated to the pathogen of interest.
These vectors can penetrate human cells and often replicate within them, but do not cause disease in the host.


i. A recombinant vector with a gene of interest inserted within the gene of a-galactosidase enzyme, is introduced into a bacterium. Explain the method that would help in selection of recombinant colonies from non-recombinant ones.
ii. Why is this method of selection referred to as insertional inactivation?

Explain how does lac operon in E. coli operate
a. in the absence of an inducer.
b. in the presence of an inducer.

a. Where is microsporangium located in an angiosperm? State the functions of tapetum and the other three layers of microsporangium.
b. Describe the structure of the male gametophyte produced as a result of microsporogenesis.
c. State the functions of each part of the male gametophyte.

Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.

Read the following text carefully and answer the questions that follow:
The following is the illustration of the sequence of ovarian events (a-i) in a human female.

i. Identify the figure that illustrates ovulation and mentions the stage of oogenesis it represents. (1)
ii. Name the ovarian hormone and the pituitary hormone that have caused the above-mentioned event. (1)
iii. Explain changes that occur in the uterus simultaneously in anticipation. (2)
OR
Draw a labelled sketch of the structure of a human ovum prior to fertilization. (2)

Read the following text carefully and answer the questions that follow:
A healthy immune system defends the body against disease and infection. But if the immune system malfunctions, it mistakenly attacks healthy cells, tissues, and organs. Called autoimmune disease, these attacks can affect any part of the body, weakening bodily function and even turning life-threatening.

i. Why are autoimmune diseases called degenerative diseases? (1)
ii. Name the autoimmune disease of body muscles. (1)
iii. Which types of immunity is provided by T-lymphocytes? (2)
OR
Which immune cells form humoral immune system? (2)