Answer: A

Explanation:

Mycoplasma bacteria can be transmitted from one person to another through the air. When an infected person coughs or sneezes, tiny droplets containing the bacteria can be released into the air. Another person can become infected by breathing in these droplets or touching a surface contaminated with bacteria and then touching their face.

Answer: C

Explanation:

Chloroplast: These are green pigments found in green plants involved in photosynthesis. Therefore, it is known as the 'kitchen of the cell'. These contain chlorophyll and other carotenoids. Hence statement 1 is correct.

Leucoplasts: It is colorless and stores food in the form of starch, fat and protein. It is found in the roots and underground stem. Hence statement 2 is also correct.

Answer: D

Explanation:

Ribosomes can be found floating within the cytoplasm. They are associated with the endoplasmic reticulum or in a free state. Hence option (a) is not correct.

Nucleus is present in the cell. Hence option (b) is not correct.

Chloroplasts are present in the cytoplasm of plant cells. Hence option (c) is not correct.

The nuclear membrane surrounds the nucleus of the cell and the cell membrane surrounds the cell. Hence option (d) is correct.

Answer: C

Explanation:

Ribozymes are RNA molecules that catalyze or autocatalyze sequence-specific cleavage. They are found in viruses, plants, and mammals and act as RNA cutting enzymes. Ligase, deoxyribonuclease, lysozyme are proteinase enzymes, which are made of proteins whereas ribozymes have RNA as structural components.

Answer: D

Explanation:

The causes of diseases related to human genes can be detected through DNA sequencing. For example, DNA sequencing has been used to understand the causes of HIV/AIDS, cancer, and many other genetic diseases. Hence statement 1 is correct.

Through DNA sequencing, disease-fighting species can be developed in animals. For example, DNA sequencing has been used to develop malaria-resistant mosquitoes and HIV-resistant pigs. Hence statement 2 is correct.

Through DNA sequencing, disease can be prevented before symptoms appear in a person. For example, DNA sequencing can be used to identify people at high risk for breast cancer, so they can receive early diagnosis and treatment. Hence statement 3 is correct.

Golden rice is a type of rice that contains a nutrient called beta-carotene. Beta-carotene can be converted into vitamin A, which is important for vision and the immune system. Gene sequencing technology has been used in the creation of golden rice. Hence statement 4 is correct.