Which phase of meiosis results in genetic variation due to crossing over?

here are the answers to your questions:

1.1.1
The phase of meiosis that results in genetic variation due to crossing over is Prophase I. During Prophase I, homologous chromosomes pair up and exchange genetic material, a process known as crossing over, which shuffles genes and creates new combinations.
The correct option is A.

1.1.2
Let's evaluate each option:

• A Ejaculation – fusion of an egg cell and a sperm cell. This is incorrect. Ejaculation is the release of semen. Fusion of gametes is fertilization.
• B Fertilisation – release of semen from the penis. This is incorrect. Fertilization is the fusion of gametes. Release of semen is ejaculation.
• C Gestation – embedding of a fertilised ovum. This is incorrect. Gestation is the period of development of an embryo/fetus. Embedding of a fertilized ovum is implantation.
• D Ovulation – release of an egg cell from the ovary. This is correct. Ovulation is the process where a mature egg is released from the ovary. The correct option is D.

1.1.3
Nucleic acids (like DNA and RNA) are large polymers made up of repeating monomer units. These monomer units are called nucleotides. Therefore, nucleotides are the building blocks of nucleic acids.
The correct option is A.

1.1.4
Let's evaluate the types of reproduction:

• A Ovipary: Animals lay eggs that hatch outside the mother's body.
• B Vivipary: Young develop inside the mother's body and receive nutrients directly from the mother (e.g., via a placenta), resulting in live birth.
• C Parental care: Any behavior by parents to enhance the survival of offspring.
• D Ovovivipary: Eggs are retained inside the mother's body, and the young develop within these eggs, nourished primarily by the egg's yolk. They hatch inside the mother and are then born live. This matches the description. The correct option is D.