1)Name features that enable the placenta to carry out its function
2)State the role of the amniotic fluid
3)what differentiates anaphase 1 from the other stages of cell division
4)State functions of the pollen tube
1) The features that enable the placenta to carry out its function include:
- Increased surface area: The placenta has numerous villi (finger-like projections) that increase the surface area available for nutrient and gas exchange between the mother and fetus.
- Thin membrane: The placental membrane is thin, allowing for efficient diffusion of nutrients, gases, and waste products.
- Maternal blood supply: The placenta is connected to the mother's uterine wall through blood vessels, allowing for the transfer of oxygen, nutrients, and antibodies from the mother to the fetus, as well as removal of waste products.
2) The role of amniotic fluid is to provide protection and support to the developing fetus. It serves several functions:
- Cushioning: The amniotic fluid serves as a shock absorber, protecting the fetus from mechanical shocks or minor injuries.
- Temperature regulation: It helps in maintaining a stable temperature around the fetus, protecting it from extreme temperature variations.
- Movements: The fluid allows the fetus to move and develop its muscles and skeletal system.
- Allows growth: The fluid provides space for a growing fetus, helping with the development of organs and limbs.
- Prevents adhesion: The fluid also prevents the fetus from sticking to the amniotic sac, allowing for proper growth and movement.
3) Anaphase 1 is a stage of cell division specific to meiosis, which is different from mitosis and anaphase 2. In anaphase 1:
- Chromosome pairs separate: In anaphase 1, homologous chromosomes, each consisting of two sister chromatids, separate and migrate to opposite poles of the cell.
- Independent assortment: Anaphase 1 also leads to independent assortment, where each pair of homologous chromosomes line up randomly at the cell equator, resulting in a diverse combination of genetic material in the resulting daughter cells.
- Reduction in chromosome number: Anaphase 1 results in a halving of the chromosome number in the daughter cells, contributing to the genetic diversity of offspring.
4) The pollen tube plays several important functions in plant reproduction:
- Pollen delivery: The tube grows from the pollen grain and carries the male gametes (sperm cells) to the female reproductive organ of the plant, usually the stigma of a flower.
- Nutrient uptake: The pollen tube absorbs and transports essential nutrients, such as sugars and amino acids, from the surrounding tissues to support the growth and development of the pollen tube and the male gametes inside it.
- Protective role: The pollen tube creates a protective pathway for the male gametes, shielding them from external environmental factors and assisting in their successful delivery to the female reproductive organ.
- Fertilization: Once the pollen tube reaches the ovule, it penetrates the female reproductive structures and delivers the male gametes to the female gametes, enabling fertilization and subsequent seed formation.