Microorganisms

Q.

Can microorganisms be seen with the naked eye? If not, how can they be seen?

Q.

Describe any two uses of bacteria in industry.

Q.

How to culture Rhizobium bacteria?

Q. Which bacteria is used for making vinegar?

Q. Bacteria has an undefined nuclear region containing only nucleic acids known as 'nucleoid'.

1. True
2. False

Q.

Explain the role microorganisms in improving soil fertility.

Q.

The old curd that is added to milk to make curd is called the ____________.

Q. ___ are the closest ancestors for all living organisms.

Q. Write short notes on

(b) Polio.

Q.

Microorganisms can be seen with the help of a ____.

Q.

Which of these is an edible fungus?

1. Mushrooms

2. Moulds
3. E.coli
4. Cyanobacteria

Q.

Putrefying bacteria act upon?

1. Fats

2. Starch

3. Protein

4. Carbohydrate

Q.

Which of these best describes the method of survival of Acidophiles?

1. They can survive acidic conditions as they produce alkaline compounds to balance them

2. They are able to balance the cell's internal environment by ion exchange

3. Their cell walls are specialized in order to stop the acid molecules from entering the cell

4. The cell walls produce enzymes that can cause favorable changes in the pH of the environment/ acidic solution

Q.

Which of the following diseases is/are caused by viruses?

1. Smallpox

2. AIDS

3. All the above

4. Common cold

Q.

What vitamins are in algae?

Q. Baker’s yeast is also known as:
A. Saccharomyces cerevisiae
B. Saccharomyces ludwingii
C. Saccharomyces octosporus
D. Schizosaccharomyces (1 marks)

Q. "Abnormally large number of WBC's in the blood are usually an indication of some infection in our body." Comment on the statement.

Q.

How do viruses begin?

Q.

Match these microorganisms with the plants they affect.

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{a. Puccinia hordei}& \text{i. Okra}\\ \text{b.Yellow vein mosaic virus}& \text{ii. Oranges}\\ \text{c. Xanthomonas axonopodis}& \text{iii. Barley}\\ \text{d. Yellow rust}& \text{iv. Wheat}\end{array}$

1. a ­i, b­ iv, c ­iii, d­ ii

2. a­ iv, b­ i, c ­ii, d­ iii

3. a ­ii, b ­iii, c­ i, d­ iv

4. a ­iii, b ­ii, c ­iv, ­i

Q. Name two diseases caused by a Protozoan. What are their causal organisms?

Q.

Choose a unicellular organism from the following.

a. Lactobacilli

b. Yeast

c. Spirogyra

d. Mushroom

1. a

2. a and b

3. c and b

4. c and d

Q. Bacteria has an undefined nuclear region containing only nucleic acids known as 'nucleoid'.

1. True
2. False

Q. Viruses multiply only inside the host.

1. False
2. True

Q. Fungus without any mycelium is

1. Albugo
2. Agaricus
3. Puccinia
4. Saccharomyces

Q. All cells arise from pre-existing cells. Justify.

Q. Is a Flagellum with four basal rings specific for Gram negative bacteria or Gram Positive Bacteria?

Q. Who among the following scientists discovered the vaccine for small pox?

1. Louis Pasteur
2. Edward Jenner
3. James Watson
4. Alexander Fleming

Q.

Malaria is caused by a bacterium.

1. True
2. False

Q. Match the entries of column $1$ with those of column $2$.
$\begin{array}{cc}\text{column1}& \text{column 2}\\ \text{a. Dicots}& i.\text{Wolffia}\\ \text{b. Monocots}& ii.\text{Eucalyptus}\\ \text{c. Largest flower}& iii.\text{Mango}\\ \text{d. Smallest flower}& iv.\text{Jowar}\\ \text{e. Tallest plant}& v.\text{Raffiesia}\end{array}$

Q. During which of the following intervals did life originate on the Earth?

1. Mesozoic era
2. Proterozoic eon
3. Cambrian period
4. Archean eon